Return to the Cloudy Nights Telescope Reviews home pageAstronomics discounts for Cloudy Nights members
· Get a Cloudy Nights T-Shirt · Submit a Review / Article

Click here if you are having trouble logging into the forums

Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu… uh, User

Equipment Discussions >> Binoculars

Pages: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | (show all)
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
127mm f/5.5 binocular
      #5262069 - 06/08/12 02:52 PM Attachment (508 downloads)

Well, I "pulled the trigger" on two 127mm f/5.5 Istar achromats in collimatable lens cells to build binoculars using 3.1 inch secondary mirrors relaying lightcone to 2 inch diagonals in low profile helical focusers which relays to 1 1/4 inch diagonal.

Raytrace shows full illumination over 27mm lightcone at fieldstop of 19mm and 24mm Panoptic eps.

This will be a fun project that may be my ultimate Milky Way sweeper.

CAD drawing shows layout for 6 inch f/5...this will be same design for 5 inch f/5.5.



Edited by Mr. Bill (06/09/12 11:55 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mark9473
Postmaster
*****

Reged: 07/21/05

Loc: 51°N 4°E
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5262211 - 06/08/12 04:44 PM

One of my cherished memories is a view, some 22 years ago, of the Great Orion Nebula through a 5" f/5 scope under mag 7 skies. I can only dream of getting that with two eyes.

Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: Mark9473]
      #5262350 - 06/08/12 06:57 PM

Bill,
If you wish full illumination across a 27mm field stop (or whatever the desired circle), your mirrors must be large enough to field the full envelope of light contributing to image formation. In your drawing here, the mirrors have been undersized (or located too near the objective), and in the case of the first mirror may result in *reduced* aperture.

What are the 'strange' rays emanating from the ~3/4 radius on the objective. They serve no useful purpose for ray tracing. Indeed, it seems they've led you astray. Get rid of them, and consider only the outermost pair of rays, which accurately represent the light bundle for 100% illumination to the field edge.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5262474 - 06/08/12 08:34 PM

Glenn

I show the drawing (not mine) only to give general layout of my design, not dimensions. It is obvious that there it considerable vignetting as drawn.

If you take this and scale it for 5 inches instead of 6, and adjust the light cone for f/5.5 instead of 5, you will see there is no vignetting.

The raytrace I did on paper shows full illumination over 27mm which is the fieldstop of the 24mm Panoptic.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5285038 - 06/23/12 10:41 AM Attachment (203 downloads)

Just got back from observing trip in central Nevada and found box from Istar waiting.

Coatings are almost invisible on these....reminds me of the coatings on my Fuji 25x100s. Definitely different coatings than on my Istar 6 inch f/5 lens cell.

Interferograms show RMS on both 0.020 and P-V 0.215 and 0.229 which bodes well, certainly for the low magnification views which these are intended.

Be interesting to build box to test monocularly with high power.

Note consecutive serial numbers.



Post Extras: Print Post   Remind Me!   Notify Moderator  
Rich V.
Post Laureate
*****

Reged: 01/02/05

Loc: Lake Tahoe area, Nevada, USA
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5285078 - 06/23/12 11:06 AM

Now the fun begins......

Rich


Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: Rich V.]
      #5285380 - 06/23/12 02:27 PM

Bill,
With good figures such as these lenses posses, you'll be good to 150X. The 5" f/5 bino I built for a friend has objectives having about 1/3 wavefront errors, and we've used Nagler 4.8mm eyepieces for about 130X to quite good effect. Exciting times ahead for you!


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5285409 - 06/23/12 02:52 PM

Am building box next week to test out monocular.



Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5285414 - 06/23/12 02:54 PM

Quote:

Bill,
With good figures such as these lenses posses, you'll be good to 150X. The 5" f/5 bino I built for a friend has objectives having about 1/3 wavefront errors, and we've used Nagler 4.8mm eyepieces for about 130X to quite good effect. Exciting times ahead for you!




Glenn

Did you use 3 mirror design in my above CAD drawing?



Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5285466 - 06/23/12 03:21 PM

If my calculation is correct, with RMS 0.020, the Strehl ratio is 96.8%.

If that is the correct RMS value as shown on the report, that's much better than the 88% minimum promised.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Rich V.
Post Laureate
*****

Reged: 01/02/05

Loc: Lake Tahoe area, Nevada, USA
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5285542 - 06/23/12 04:09 PM

That's a pleasant surprise, Bill. It really could make a killer binoscope with good high magnification capabilities as well as your intended WF application.

Rich


Post Extras: Print Post   Remind Me!   Notify Moderator  
Unknownastron
professor emeritus
*****

Reged: 04/06/05

Loc: CatsEye Observatory,Rural Sout...
Re: 127mm f/5.5 binocular new [Re: Rich V.]
      #5285590 - 06/23/12 04:37 PM

Oh how I wish I lived near you and could see this creation take shape. Much work and much tweaking ahead but the result will be an instrument for life. Keep us posted.
Clear skies and clean glass,
Mike


Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: Unknownastron]
      #5286309 - 06/24/12 05:12 AM

That 5" f/5 I built did indeed use a 3-mirror system. The first mirror is a 2.14" m.a., and the other two are 1.52" m.a., arranged to direct the light inward and then upward to the eyepieces. In spite of the somewhat smaller-than-46mm field stop on widest field 2" eyepieces, the 1.52" mirrors cause no discernible edge-of-field darkening. All mirrors were purchased from Lumicon, and have enhanced aluminum coatings.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5287285 - 06/24/12 07:25 PM

Looks like total cost of components is about $2K (not including eps)....certainly reasonable when you consider what a similiar product would cost if available.

The only other similiar (5 inch) binoscope I know about that can be ordered now is the Vixen which is $4K for the OTA.

This will "blow the doors" off the Vixen (or Garrett's 6 inch for that matter)... I am willing to bet a C note on that.



Edited by Mr. Bill (06/24/12 07:35 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5287794 - 06/25/12 02:20 AM

It most definitely will blow the doors off the current crop of Chinese-made offerings. I'd also choose it over the vaunted Fuji 150mm models in a heartbeat!

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5288216 - 06/25/12 10:54 AM

Quote:

I'd also choose it over the vaunted Fuji 150mm models in a heartbeat!




Been there, done that...time to move on.



Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5288503 - 06/25/12 02:14 PM

Just ordered 99% 1 1/4 and 2 inch pairs of diagonals from Stellervue.

Ordered the other 3.1 from Discovery.

Could have this together in time for the GSSP SP next month!

Edited by Mr. Bill (06/25/12 06:02 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5288853 - 06/25/12 06:00 PM

Given some thought to both inter and intra barrel collimation...

Current idea is to build separate barrel boxes so that each can be collimated individually, attach boxes so that they can be pivoted (pitch) for altitude collimation correction and shimmed to correct for azimuth correction.



Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5288983 - 06/25/12 07:29 PM

That'll add mass and needless complexity. One rigid body is best. You can carefully align and then lock down five of the six mirrors, leaving just the one to do the tiny tweaks occasionally necessary.

In the 'big box' 5" f/5 bino I built, the larger, first mirrors are tilt adjustable. The other, smaller ones are mounted via RTV to pieces of square aluminum tubing cut at 45 degree angles, and act just like small periscopes. The mutually parallel sides to which the mirrors' back surface are RTV'd make alignment of these two pairs of mirrors absolutely reliable. The beauty of this system is that the 45 degree cuts need not be to micrometric precision--errors can be as large as a couple of degrees. Why? Because the light exiting will be parallel to that entering, even with considerable rotation of the unit.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5289037 - 06/25/12 07:55 PM

OK...so first mirror (3.1) would be adjustable.

So one of these could have rotation in the azimuth and could be shimmed to create altitude.

Does that sound right?



Post Extras: Print Post   Remind Me!   Notify Moderator  
Wes James
Postmaster
*****

Reged: 04/12/06

Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5289662 - 06/26/12 08:07 AM

Would love to see some drawings/pictures of some of this... for us "visual" learners!

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Wes James]
      #5289697 - 06/26/12 08:35 AM

Quote:

Would love to see some drawings/pictures of some of this... for us "visual" learners!




Will start a thread on ATM forum and post link on this thread.

Still waiting on parts and finalizing construction details.



Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5289884 - 06/26/12 10:31 AM

One would be tiltable in the fore-aft direction, which would cause the image to move up-down. The other would rotate about the optical axis (as coming from the objective, not that as reflected), which would cause the image to move L-R. As long as reasonable care has been exercised in the dimensioning of components and their placement, the rotation of the one mirror in order to effect collimation will be so slight that image rotation will not be an issue.

When I first assembled the 5" f/5, I had adjusted the tiltable mirrors on the rear assembly merely by eye. When I attached this unit to the body, the bino was not far from collimation, only small adjustments being required. I say this to assure you that as long as you observe (my version) of the carpenter's dictum which states, "measure thrice, cut once", your bino will come together nicely and perform splendidly.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5289934 - 06/26/12 11:04 AM

Glenn

Just ordered 2 of these....using 1 box design and collimate with secondary holders.

http://www.astrosystems.biz/sechold.htm

Edited by Mr. Bill (06/26/12 01:51 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5290201 - 06/26/12 01:41 PM

Looks like all the bits and pieces will show up by end of week.

Soon as I verify a few measurements (like back focus through diagonals), I can draw up the dimensions and start cutting box pieces.



Post Extras: Print Post   Remind Me!   Notify Moderator  
mercedes_sl1970
professor emeritus
*****

Reged: 12/02/05

Loc: Canberra, Oz
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5291212 - 06/27/12 08:39 AM

Looking forward to following the build of these binos. Should be fascinating.

Andrew


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: mercedes_sl1970]
      #5291920 - 06/27/12 05:22 PM Attachment (120 downloads)

Finished layout...cut box pieces out of cabinet grade birch plywood.



Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5291961 - 06/27/12 05:41 PM Attachment (110 downloads)

Diagonals (99% dielectric) and low profile helical focuser with 1 3/4 inch travel....

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5293500 - 06/28/12 03:57 PM Attachment (109 downloads)

Box assembled and waiting for parts...

Post Extras: Print Post   Remind Me!   Notify Moderator  
Rich V.
Post Laureate
*****

Reged: 01/02/05

Loc: Lake Tahoe area, Nevada, USA
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5293522 - 06/28/12 04:12 PM

Moving along nicely, Bill!



Rich


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Rich V.]
      #5293530 - 06/28/12 04:22 PM

Yeah Rich....

I'm getting better at this box building after the 6 inch f/5 EE Barnard box considering the *BLEEP* radial arm saw I have.

The rail apparently has a slight amount of roll in it over full travel.

"Good enough for government work"....(I should know)



Post Extras: Print Post   Remind Me!   Notify Moderator  
Andresin150
Pooh-Bah
*****

Reged: 08/14/07

Loc: Bogotá - La Calera / Colombia
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5293596 - 06/28/12 05:05 PM

looks promising!

Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: Andresin150]
      #5293634 - 06/28/12 05:35 PM

A suggestion. Place a thin-walled divider between the two optical paths so as to ensure no light leakage through one objective onward to the opposite eyepiece. It may not be necessary--especially so if the optical path length from first mirror to focus is long--but it never hurts.

This is looking rather reminiscent of my first 5" build, of which I will eventually post photos, both of the outside and the innards. (But I made use of black anodized aluminum plates for both the objective cell and focuser/mirror system supports.)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5293758 - 06/28/12 06:55 PM

Thanks Glenn...wow, that's weird. I was JUST thinking about a divider between the objectives.

Will do.



Post Extras: Print Post   Remind Me!   Notify Moderator  
marcelof
sage


Reged: 05/24/10

Loc: Necochea,Bs As,Argentina
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5293984 - 06/28/12 09:32 PM

It is the style box!!! I understand that to use pipes of aluminium would complicate the things and to raise the costs. We wait anxious for the results!!
Good luck!


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: marcelof]
      #5294807 - 06/29/12 12:33 PM Attachment (116 downloads)

Box with divider on mount...

Secondary holders on truck for delivery, according to UPS tracking so I will be able to put together at least one side to check out this weekend.

3.1 mirror and flocking material (the last of parts ordered) should show up today or tomorrow....

Got my fingers crossed that I got it right on paper...



Edited by Mr. Bill (06/29/12 01:14 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5295549 - 06/29/12 09:39 PM Attachment (106 downloads)

First light with one side....other 3.1 mirror hasn't arrived...maybe tomorrow.

Collimation appears to be fairly straightforward (at least for one barrel.)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5295596 - 06/29/12 10:10 PM Attachment (93 downloads)

Once I shorten long adjustment knobs, I can move diagonal back another inch and push components back further into lightcone, increasing edge of field illumination even more (about 60-70% now) Like to get 80% which I think is very doable.

I'll still have a couple of inches for hinged trapdoor in rear to tweak adjustments.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Rich V.
Post Laureate
*****

Reged: 01/02/05

Loc: Lake Tahoe area, Nevada, USA
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5295660 - 06/29/12 11:10 PM

Looking great, Bill. What is the minimum IPD as shown in the photo above when the diagonals meet?

Any sign of sag in the diagonal/focuser train?

The Bino Box lives!

Rich


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Rich V.]
      #5295668 - 06/29/12 11:23 PM

Minimum IPD as shown around 65mm (can get less by offsetting)...mine is 67mm. I probably could have increased objective spacing, but things worked out OK. Whew!!

Optical train looks very robust....still lots of tweaking but looks like everything will work out.

That's a relief after spending $2K betting on paper raytrace.



Post Extras: Print Post   Remind Me!   Notify Moderator  
Smithfr2000
member


Reged: 09/12/09

Loc: Nantes - France
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5295922 - 06/30/12 06:29 AM

Very interesting work ! Well done !

I do not understand how you achieve collimation with knobs inside the box ? Any explication ?
Thanks a lot.


Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: Smithfr2000]
      #5296254 - 06/30/12 11:54 AM

What's the weight? My 1996 version of the 5" weighed 27 pounds, and I want to shave a fair bit off the 2012 re-do.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5296410 - 06/30/12 02:00 PM

Looks like just under 30 pounds, Glenn.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5296894 - 06/30/12 08:11 PM Attachment (113 downloads)

Received second 3.1 mirror by priority mail today.

Achieved near perfect binocular collimation centering a telephone pole 1 mile distant while maintaining reasonable intrabarrel collimation.

Once figured out what I was doing it was easy and alignments very robust.

Next step, star test.

Focusers work perfect in position shown and will result in very little change in position during altitude rotation. Should be able to sit and sweep from horizon to zenith without much if any seat adjustment.

Note: found helical threading to be too sloppy to precise maintain collimation alignment....used Teflon pipe tape on drawtube to provide stiffness and friction without stiction.



Edited by Mr. Bill (07/01/12 03:15 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5297117 - 06/30/12 11:22 PM

Another interesting thing now that collimation is achieved is there is a 3-4mm difference in ep height when fine focused with the same eye.

I assume that is the difference in focal length between objectives.

That's around 1/2% so I guess that's probably normal.

I could put a shim on the long barrel to even out the ep height.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5297647 - 07/01/12 10:39 AM Attachment (104 downloads)

First light this morning between moonset and first light of dawn (3:00-4:00 AM)

"My God, it's full of stars."

This is going to be the "killer app" of Milky Way cruising machines. Panoptic 19 seems to be a perfect match for this...37x and 3.5mm exit pupil.

Much more to do...flocking, staining, varnishing but optical design proved.

Contrast even without flocking is excellent and dark nebulae and starclouds are breathtaking...even better than my trusty BT100s.

Maybe someday I'll be able to compare side by side with the Fuji 25x100s.

Total cost without eyepieces was around $2200.


Post Extras: Print Post   Remind Me!   Notify Moderator  
marcelof
sage


Reged: 05/24/10

Loc: Necochea,Bs As,Argentina
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5297710 - 07/01/12 11:20 AM

That advantages has this disposition versus place only four diagonals going out on the later part?
(Besides saving both biggest mirrors.)
Anyhow remain the eyepieces vertical to up, achieving the 90 º of inclination so looked.

Edited by marcelof (07/01/12 11:24 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Rich V.
Post Laureate
*****

Reged: 01/02/05

Loc: Lake Tahoe area, Nevada, USA
Re: 127mm f/5.5 binocular new [Re: marcelof]
      #5297757 - 07/01/12 11:48 AM

Marcelo, if I understand you correctly, using two diagonals attached to the rear of the box so as to allow 90° viewing would present images 180° rotated relative to each other. One side would have the image rotated right 90° and the other side rotated left 90°.

Using the larger first mirrors to orient the images 90° initially allows the two diagonals on each side to mimic a rhomb which creates no rotational error as they are turned for IPD adjustment.

Rich


Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: Rich V.]
      #5297797 - 07/01/12 12:15 PM

I knew you'd succeed, Bill! And talk about short order, too--it came together mighty quickly. I'm not surprised to see that even non-blackened, the contrast is good. This is due in part to the fact that unlike a 'streamlined' bino, wherein the main tubes closely follow the converging light cone and thus too easily allow scattered light to do harm, your box has its walls, for the most part, well removed from the image-forming light cone. And the self-shadowing provided by the back side of the front board and lens cells is a big contributor, too.

Making your own binocular isn't so hard, is it? The very first astro instrument I built was a 5" bino, too. If one gets over the needless fear of super precision being required, it's not much harder than designing a Dobsonian scope.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5298010 - 07/01/12 02:35 PM Attachment (74 downloads)

Quote:

I knew you'd succeed, Bill! And talk about short order, too--it came together mighty quickly. I'm not surprised to see that even non-blackened, the contrast is good. This is due in part to the fact that unlike a 'streamlined' bino, wherein the main tubes closely follow the converging light cone and thus too easily allow scattered light to do harm, your box has its walls, for the most part, well removed from the image-forming light cone. And the self-shadowing provided by the back side of the front board and lens cells is a big contributor, too.

Making your own binocular isn't so hard, is it? The very first astro instrument I built was a 5" bino, too. If one gets over the needless fear of super precision being required, it's not much harder than designing a Dobsonian scope.




That's about right....

Preparation before cutting pieces is essential. Raytracing and measuring backfocus of components like diagonals will prevent surprises.

Making the box refractor before this allowed me to hone up my woodworking skills but one slip and....

This was done using only a radial arm saw and floor drill press. I would not attempt this project without them; the precision of cuts is beyond hand tools and Skil saws.

Taking a break today from project...my 80 trees are hollering for a deep watering!



Edited by Mr. Bill (07/01/12 10:22 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5298036 - 07/01/12 02:48 PM

Hey, just made Postmaster.....only took 7 1/2 years.



Post Extras: Print Post   Remind Me!   Notify Moderator  
marcelof
sage


Reged: 05/24/10

Loc: Necochea,Bs As,Argentina
Re: 127mm f/5.5 binocular new [Re: Rich V.]
      #5298040 - 07/01/12 02:51 PM

It is difficult to express with words.
I refer to this:
Only that constructed with the materials used by Mr. Bill.
I counted badly or only it uses two diagonal mirrors????


Post Extras: Print Post   Remind Me!   Notify Moderator  
Rich V.
Post Laureate
*****

Reged: 01/02/05

Loc: Lake Tahoe area, Nevada, USA
Re: 127mm f/5.5 binocular new [Re: marcelof]
      #5298058 - 07/01/12 03:06 PM

Marcelo, what you are talking about is the Matsumoto EMS mirror system. It's the ultimate solution for a bino back. Matsumoto uses an elegant 2-mirror system that produces a correct image. There's a lot more engineering and precision fabrication to it than using 2- 90° factory diagonals together as Bill has done, though.

Matsumoto EMS

Rich


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Rich V.]
      #5298085 - 07/01/12 03:27 PM Attachment (85 downloads)

My understanding is that the EMS system only works well with relatively slow f ratios such as f/7 and higher.

My setup provides no vignetting and outstanding edge of field illumination on fast refractors using f/5 or in my case here f/5.5.

Here's a 6 inch f/8 Tak tubes system using the EMS. I took this last year at the Okie-Tex SP. Only cost $28K.



Edited by Mr. Bill (07/01/12 03:47 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Wes James
Postmaster
*****

Reged: 04/12/06

Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5298492 - 07/01/12 08:33 PM

...*drool*...

Post Extras: Print Post   Remind Me!   Notify Moderator  
Wes James
Postmaster
*****

Reged: 04/12/06

Re: 127mm f/5.5 binocular new [Re: Wes James]
      #5298493 - 07/01/12 08:33 PM

You've got an impressive project going here, Bill- Impressive!!

Post Extras: Print Post   Remind Me!   Notify Moderator  
marcelof
sage


Reged: 05/24/10

Loc: Necochea,Bs As,Argentina
Re: 127mm f/5.5 binocular new [Re: Wes James]
      #5298580 - 07/01/12 09:47 PM

I supposed that eliminating the elliptical mirrors the beams they follow his path, placing then diagonals in the back part. The box should be little long mas. I do not have the elements to experiment, because of it I ask.
My experience says to me that eliminating the prisms a binocular remains much more luminous. Will it be more luminous than the fuji 150? Or maybe equal?


Post Extras: Print Post   Remind Me!   Notify Moderator  
mercedes_sl1970
professor emeritus
*****

Reged: 12/02/05

Loc: Canberra, Oz
Re: 127mm f/5.5 binocular new [Re: Wes James]
      #5298749 - 07/02/12 12:01 AM

Quote:

You've got an impressive project going here, Bill- Impressive!!




You'd think he would have it finished by now. It really is only a fairly trivial project....! (Yeah, right).

Andrew

ps I bet the bet the views will be fabulous


Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: mercedes_sl1970]
      #5298958 - 07/02/12 06:46 AM

The elegance of the Matsumoto system lies only in the fact that that two mirrors deliver a normal, non mirror-reversed view. In other respects the system leaves much to be desired due to the fact that it requires the user to tweak things in order to have the eyepieces be parallel. That the erection/folding system effectively 'hangs out there' like a plumber's nightmare just waiting to be bumped and hence knocked out of collimation gives me the heebie-jeebies! This is NOT robust, by my engineering standards.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Rich V.
Post Laureate
*****

Reged: 01/02/05

Loc: Lake Tahoe area, Nevada, USA
Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5299169 - 07/02/12 10:35 AM

Amen to that, Glenn! There's a whole lot going on mechanically with the EMS design compared to the sheer simplicity of this three mirror design.

I'm looking forward to looking through Bill's Bino Box!

Rich


Post Extras: Print Post   Remind Me!   Notify Moderator  
Wes James
Postmaster
*****

Reged: 04/12/06

Re: 127mm f/5.5 binocular new [Re: Rich V.]
      #5299327 - 07/02/12 03:50 PM

So what kind of image does this bino box bino give- inverted/reversed?? Can't quite wrap my mind around the answer!!
Wes


Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: Wes James]
      #5299380 - 07/02/12 04:15 PM

The view is just like that delivered by a refractor with a mirror diagonal installed--upright, but mirror-reversed L-R. The two following mirrors, due to the even number of reflections, do not alter the image orientation at all; their only purpose is to bring closer together, periscope-like, the widely separated optical axes.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5299542 - 07/02/12 05:58 PM Attachment (119 downloads)

Last woodworking step....

Sanded, applied stain and letting everything sit overnight.

Tomorrow, flocking the interior and putting first coat of Urethene Spar Varnish on.

The end is in sight!

Notice I copied the BT100s hood over the objectives...quite effective for blocking ambient light.



Edited by Mr. Bill (07/02/12 07:39 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Gordon Rayner
Carpal Tunnel
*****

Reged: 03/24/07

Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5300146 - 07/03/12 03:26 AM

Did you see the binoscope by James Stillburn in pp. 66-67 of the April Sky & Telescope? There, the image is unreversed and erect, with only two mirrors . Each telescope moves as a unit laterally, for interpupillary adjustment. The metalwork shown seems to be of a very high order,and no doubt time-consuming. But the present thread gives hope of an easier approach to an erect, unreversed image, two mirror, binoscope. The wooden box is the key.

In the Matsumoto EMS, the separation of each mirror pair is varied for IPD adjustment. In some or all, the mechanism is a Pentax 67 film camera accessory.

In the present thread, the IPD is via two mirrors, equivalent to the rhomboid prisms which swivel on many of the the 45 degree or 60 degree inclined view WW II Japanese 60, 80, 105, or 120mm binoculars.

The present wooden box structure suggests that metalworking machine tools , such as a lathe and a vertical milling machine, may not be required for a successful binoscope construction.
Mr. Bill used a radial arm saw. A sliding compound miter saw has replaced those for some applications. If applicable, the slider compound miter saw would occupy less shop space. Mine is from Harbor Freight. Adequate slide length seems to be the criterion here.

One can visualize a two mirror erect, unreversed system with a wooden box to house both telescopes:
The mirrors would be arranged as in the beamprint traces illustrated in the drawings of an Amici prism used in the second mode, as found in Mil Handbook 141, which can be found in the bibliography of this forum, or Googled. There, the entire beam passes from one roof face to the other roof face, without being halved or partially divided by the roof edge. Phantom roof edge or virtual roof edge, is a description.

For 90 degree deviation, as chosen by Mr. Stillburn, op. cit., the beamprints are 2:1 major/minor axes ratio. The axial ray has an incidence angle to 60 degrees onto the mirrors.
The Stillburn scope uses 1.414:1 major/minor axes ratio ellipses, the same proportions as the diagonal mirror of a Newtonian telescope, or the mirrors used for the 3-mirror non-compound angle reversed image system of the present thread. So, some of the mirror area is wasted in the Stillburn execution. I do not know what the ratio is in Matsumoto constructions.
One mirror would be in a fixed location inside the wood box. Its mate, which can be smaller, to accept the smaller cone diameter downstream , can be supported by a slide which is supported by a wood or metal lid of the box. The smaller mirror should be large enough to accept the entire cone when moved "upstream" for a large IPD such as 72 or 74mm.

The slide motion direction on or under the box lid,in a plane parallel to the plane of the box lid, for the 90 degree case,can come from a compound angles calculation by the reader,or from your present servant when I retrieve former work on this general topic ,which has been discussed several times in this forum , from Mssrs. Stillburn or Seronik, handbook search, top views of the Matsumoto system, ...? Mr. Stillburn sent to me some fine drawings of his system.
30 deg? 45 deg? 60 deg.?, 54.75 deg. ? I do not recall. I used 3D vectors .

Compound angles are discussed in Machinery's Handbook, finish carpentry books , and probably elsewhere, maybe in trigonometry , certainly in books on solid geometry, which use 3D vectors as the most straightforward approach. My hp48 program is for layout of a general ( not just 90 deg. , but fixed deviation once chosen) two mirror version which uses the WW II Zeiss style IPD change , in which one( and only one) of the eyepieces moves laterally by twice the motion of its roof prism. That system has been considered , but not built, in a 90 deg. overall deviation box form in which the mirrors are supported by the lid of the box.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Gordon Rayner]
      #5300453 - 07/03/12 10:40 AM

As far as image presentation, I have no problem with erect, left to right reversed. I'm used to the fields in my refractors and since I will use the Bino Box (thanks, Rich ) in conjunction with refractors, the fields are the same.

Come to think about it, this 5 inch bino which works out to a 7 inch refractor may make my 6 inch f/5 refractors redundant.



Edited by Mr. Bill (07/03/12 12:43 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5300968 - 07/03/12 05:18 PM

An EMS-like mirror configuration was an early contender for consideration when designing my friend's 'bino box' lo those many years ago. If I remember rightly, in order to have a sufficiently large footprint, the mirrors would have required a somewhat greater height on the box's top if I wanted to retain the uniform height along the full length. If I hD elected to restrict to 1.25" format eyepieces, this would have posed no problem.

My approach now is to employ a large Amici prism in conjunction with a mirror pair.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Gordon Rayner
Carpal Tunnel
*****

Reged: 03/24/07

Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5301082 - 07/03/12 06:30 PM

Yes, the focal planes would be near, or above ,a plane containing the tops of the objective lens cells. Thus the sides of the box will not be rectangular, if the surface area ( and thus the weight) of the box is to be no larger than required.

Post Extras: Print Post   Remind Me!   Notify Moderator  
RichD
Carpal Tunnel


Reged: 11/08/07

Loc: Derbyshire, UK
Re: 127mm f/5.5 binocular new [Re: Gordon Rayner]
      #5301820 - 07/04/12 07:23 AM

Amazing piece of work Bill, can only imagine the views through the finished article under your dark skies. What mag and EP will your 24mm Pans give?

Post Extras: Print Post   Remind Me!   Notify Moderator  
GamesForOne
professor emeritus


Reged: 09/29/09

Loc: Knoxville, TN
Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5303162 - 07/05/12 01:05 AM

Quote:


My approach now is to employ a large Amici prism in conjunction with a mirror pair.




I've read a 2006 report on this site that indicated the WO Amici prism was a poor performer compared to a typical mirror diagonal, especially at higher magnifications. The reviewer did not recommend it for anything but daylight observations. From whom would you buy such a prism?

Also, most large 2" Amici prisms I've seen are 45 deg. Would you use the 45 deg on the top of something like Bill's box? It would look sort of like a typical stereo microscope sticking out the top.

Or is the Amici inside the box in place of the diagonal mirror in Bill's design?

The nice thing about Bill's design is it should perform quite well at higher magnifications as well given its optical simplicity and good quality mirrors. Light transmission should be excellent as well.

I was told about 3 years ago by a well-known astro equipment importer that Chinese designers/factories were working on a 90 deg bino design using mirrors instead of prisms. I haven't seen or heard anything about it since.

---
Michael Mc


Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: GamesForOne]
      #5303520 - 07/05/12 10:34 AM

Michael,
I have a pair of 90 degree Amicis, bought from Orion but essentially the same as the WO units, which have 40mm clear apertures. I've tried them out and thy perform as expected. There is a diffraction spike formed by the roof line passing centrally through the on-axis light bundle. This is just like such a spike formed by a single-vane secondary support on a Newt. As long as the roof has no significant angle error (departure from the ideal 90 degrees for the two mutually perpendicular roof faces), one can use higher magnifications.

In my design, the pair of 'periscopic' mirrors will be ahead, directing the beams first inward to my IPD, then back, parallel to the optical axes. The. The Amici will follow, directing the beams 90 degrees upward. This has the advantage of keeping the eyepiece heights rather low, with the back end of the bino having a 'dropped shelf' of lower height than the foreword portion of the body. I like the notion of a more streamlined construction.

And I like a correct view sufficiently to accept the performance drop an Amici introduces, that being the lower transmission (about 89%, or similar to standard-reflectance mirrors) and a diffraction spike on bright objects.) At low to moderate magnifications--where the bulk of my observing will be done--there will be little visible difference between the Amici variant and one having a mirror.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5303947 - 07/05/12 03:23 PM Attachment (100 downloads)

FINALLY....

Flocking, second coat Urathane, assembly and collimation done.



Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5303949 - 07/05/12 03:24 PM Attachment (93 downloads)

Front view....

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5303953 - 07/05/12 03:25 PM Attachment (105 downloads)

Collimation made easy with access holes...man, it's DARK down there.



Edited by Mr. Bill (07/05/12 06:44 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5303954 - 07/05/12 03:26 PM Attachment (99 downloads)

Inside Bino Box...flocking done with sheets of Edmund Optics flocking paper glued with thinned down wood glue.

Edited by Mr. Bill (07/07/12 01:49 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5303985 - 07/05/12 03:49 PM Attachment (102 downloads)

A "tip of the hat" to EE Barnard...

Post Extras: Print Post   Remind Me!   Notify Moderator  
Smithfr2000
member


Reged: 09/12/09

Loc: Nantes - France
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5304022 - 07/05/12 04:23 PM

Very nice !
Thanks a lot for the pictures and the explanations about collimation.

Edited by Smithfr2000 (07/05/12 04:46 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Smithfr2000
member


Reged: 09/12/09

Loc: Nantes - France
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5304024 - 07/05/12 04:24 PM

-

Edited by Smithfr2000 (07/05/12 04:45 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Joad
Wordsmith
*****

Reged: 03/22/05

Re: 127mm f/5.5 binocular new [Re: Smithfr2000]
      #5304275 - 07/05/12 07:52 PM

I'm more than a little amazed at how fast you completed this project!

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Joad]
      #5304545 - 07/05/12 10:52 PM

Quote:

I'm more than a little amazed at how fast you completed this project!




My wife's on holiday in Ireland so I have been working without distractions to finish in time for the Golden State SP coming up in two weeks.

Will be giving a PowerPoint presentation on this project at GSSP.





Edited by Mr. Bill (07/06/12 04:16 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
JMW
Pooh-Bah


Reged: 02/11/07

Loc: Nevada
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5304702 - 07/06/12 12:48 AM

Just stumbled across this. Looks awesome. I will definitely mossy on over for a view through your new creation at the GSSP. There may be a line.

Bill, I still appreciate the tours of the dark stuff when I camped next to you at the 2009 GSSP. Seeing the dark nebula is one of the things I look forward to after viewing for several months within an hour of Reno's light dome.


Post Extras: Print Post   Remind Me!   Notify Moderator  
mercedes_sl1970
professor emeritus
*****

Reged: 12/02/05

Loc: Canberra, Oz
Re: 127mm f/5.5 binocular new [Re: JMW]
      #5305079 - 07/06/12 09:47 AM

Very impressive. Look forward to hearing about the views.

Andrew


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: mercedes_sl1970]
      #5306119 - 07/06/12 10:34 PM Attachment (121 downloads)

Ready for night trials...

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5306121 - 07/06/12 10:36 PM Attachment (114 downloads)

Another...

Post Extras: Print Post   Remind Me!   Notify Moderator  
Rich V.
Post Laureate
*****

Reged: 01/02/05

Loc: Lake Tahoe area, Nevada, USA
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5306137 - 07/06/12 10:51 PM

Wishing you a good night, Bill!


Rich


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Rich V.]
      #5306319 - 07/07/12 04:24 AM

I remember Klipchhorn speakers....my first $75 bottle of pinot noir wine....

Looking through these at M24 gives me the same sensation of the next level...

Maybe mirrors instead of prisms is the way to go...

With the 24mm Pans, pinpoint stars to the edge of the fieldstop and the contrast is definitely better than the BTs which are very, very good.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Smithfr2000
member


Reged: 09/12/09

Loc: Nantes - France
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5306413 - 07/07/12 08:21 AM

A question about collimation : Do you tweak the mirrors alone ?
Or, do you tweak also the lenses cells ?
And what about the diagonal's mirrors ?
Thanks.

Edited by Smithfr2000 (07/07/12 08:22 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Rich V.
Post Laureate
*****

Reged: 01/02/05

Loc: Lake Tahoe area, Nevada, USA
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5306610 - 07/07/12 11:37 AM

Quote:

Looking through these at M24 gives me the same sensation of the next level...

With the 24mm Pans, pinpoint stars to the edge of the fieldstop and the contrast is definitely better than the BTs which are very, very good.




I take it you were duly impressed?......

Rich


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Smithfr2000]
      #5306612 - 07/07/12 11:37 AM

The lens cells are fixed; all collimation is done with the diagonals.

There are three adjustments...rotation, tilt, and yaw.

The 1 1/4 diagonal is adjusted with a precision square to be precisely parallel to the 2 inch diagonal to eliminate field rotation.

Each barrel is adjusted for best collimation, then I tweek the right barrel (my non dominate eye) to correct the inter collimation.

I use my focused/defocused barrel technique on a star to do final collimation.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Rich V.]
      #5306621 - 07/07/12 11:42 AM

Quote:

Quote:

Looking through these at M24 gives me the same sensation of the next level...

With the 24mm Pans, pinpoint stars to the edge of the fieldstop and the contrast is definitely better than the BTs which are very, very good.




I take it you were duly impressed?......

Rich




They'll do....


Post Extras: Print Post   Remind Me!   Notify Moderator  
hallelujah
Post Laureate
*****

Reged: 07/14/06

Loc: North Star over Colorado
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5306650 - 07/07/12 12:05 PM

Quote:

They'll do....




It is 'acceptable' to be enthusiastic over your excellent piece of workmanship!

We won't hold it against you.

GREEN with Envy is another thing.

Stan


Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: hallelujah]
      #5306726 - 07/07/12 12:56 PM

Bill,
I'd be curious to see a pic looking into the objective from one side, with eyepiece installed, and another of the exit pupil...


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5306773 - 07/07/12 01:28 PM Attachment (108 downloads)

Here they are, Glenn...24mm Pan (4.35mm ep) on left, 19mm Pan (3.45mm ep) right.



Edited by Mr. Bill (07/08/12 03:09 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5306776 - 07/07/12 01:29 PM Attachment (86 downloads)

Edge of field illumination with 24mm Pan in place...tracing out on a piece of paper placed over monitor and adding missing part, I would say 70%.

Edited by Mr. Bill (07/07/12 02:41 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Gordon Rayner
Carpal Tunnel
*****

Reged: 03/24/07

Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5306859 - 07/07/12 02:21 PM

You found that there was enough looseness in the focusers' threads that you needed to use Teflon plumber's tape applied over the male threads. Stellarvue is not alone in this shortcoming. The advertising buzzword use of "CNC" does not make up for lack of proper design, manufacture, and fitting quality control .

A good threaded helical focuser should use truncated Acme or similar shallow thread profile ( inserts are available from Seco Snap-Tap, or their successor or buyout, and no doubt several other threading bit sources) rather than a standard vee. That allows optimal use of the wall thickness allowed in the spacing budget for this portion of a binocular instrument.
For a monocular telescope, wall thicknesses are much less constrained, but that is not an excuse for sloppy thread fits and non-optimal thread profiles, and lack of multiple threads, "CNC" or not.

For a given IPD, there are limits on the glass diameter and the wall thicknesses of the metal parts of the eyepieces . That is why multiple lead/"multiple start"/ multiple threads are used in professionally manufactured binocular instruments ( and in many common food and drink containers).

For a given wall thickness, multiple threads allow more axial motion per turn. That is important in optical focusing. The material savings in production of millions of PETE beverage bottles must be substantial.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Gordon Rayner]
      #5306883 - 07/07/12 02:38 PM

Gordon...helical focusers are not Stellervue's.

Bought these several years ago (anticipating this project) and cannot remember vendor or manufacturer...no markings.

I will comment on one problem with the 2 inch Stellervue diagonals....the drawtube barrels are baffled with grooving but the finish was shiny anodizing.

I discovered this when I was observing the moon and moved off axis about 20 degrees when the fov became flooded with light where there should have been none. Turned out the diagonal drawtube was the cause in spite (and probably a result of) of the grooved baffling.

That just ticks me off that manufacturers just don't get it...my Moonlite focuser had the same issue and when I called Ron at Moonlite he didn't think it was a big deal.

A few shots of Krylon Ultra Flat Black solved the problem on both items.

Curiously,the Stellervue 1 1/4 inch diagonal drawtube barrels were both grooved and properly blackened. Probably different manufacturers.



Edited by Mr. Bill (07/07/12 07:15 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Rich V.
Post Laureate
*****

Reged: 01/02/05

Loc: Lake Tahoe area, Nevada, USA
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5306890 - 07/07/12 02:44 PM

What is the source of the intrusion into the light path? To fuzzy to tell...

Looks great!

I had to paint the inside of my SV 2" diagonal as well. That in addition to the shiny 2" Feathertouch drawtube baffles bothered me. You'd think this would be considered. UFB paint made a big difference.

Rich

Edited by Rich V. (07/07/12 02:50 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Rich V.]
      #5306910 - 07/07/12 02:59 PM

Quote:

What is the source of the intrusion into the light path? To fuzzy to tell...

Rich




Hi Rich

the bottom of the helical drawtube.


Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5306948 - 07/07/12 03:29 PM

Good field illumination, and certainly no prism-induced 'fingernail' extra-pupil reflections to send unwanted light into the eyes. The area immediately surrounding the exit pupil looks well enough 'black', and so the only light of any consequence making it through to the retina is that forming the image.

Have you tried bumping up the magnification, on one side only if tyis is all you can do, to see how the image holds up? I should think a 1mm exit pupil, or around 130X, is useable. Of course, in bino mode this will place pretty tight constraints on collimation. This is why I implemented external up-down and left-right adjustment knobs for easy and instant on-the-fly tweaking. Such things as loose focusers and wiggling eyepieces (primarily due to slight differences in barrel diameters) can be accounted for the instant collimation drifts as the bino is moved about.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5306999 - 07/07/12 04:10 PM

I would say for a binocular where 50% edge illumination is considered good (a la EdZ) that 70% is very good.

My monocular 6 inch f/5 box refractor is about 80%, but it doesn't have two diagonals in the light path to deal with.


Post Extras: Print Post   Remind Me!   Notify Moderator  
RichD
Carpal Tunnel


Reged: 11/08/07

Loc: Derbyshire, UK
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5307150 - 07/07/12 05:55 PM

I'd say 70% is at least very good and probably excellent! I bet you can't wait for winter and M42...

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular *DELETED* new [Re: GlennLeDrew]
      #5307177 - 07/07/12 06:22 PM

Post deleted by Mr. Bill

Post Extras: Print Post   Remind Me!   Notify Moderator  
Refractor6
Post Laureate
*****

Reged: 10/20/04

Loc: Vancouver B.C. , Canada
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5307214 - 07/07/12 07:41 PM

Awesome project Mr. Bill!!!

Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: Refractor6]
      #5308245 - 07/08/12 01:10 PM

Ah, but overexposed is what better reveals scattering of light outside the image forming bundle. Some might underexpose in order to make the situation look good. A photo and the display device have much smaller dynamic range than our visual system. The exposure must be appropriate for the element being highlighted. Showing the bright exit pupil well will make the surrounding dark region (the image of the innards of the bino and eyepiece) much underexposed.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5308429 - 07/08/12 03:11 PM

Just for you Glenn...

I put the original picture back in...eye dander and all.



Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5309482 - 07/09/12 09:41 AM Attachment (141 downloads)

Put together a parts list for my PowerPoint presentation...

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5309497 - 07/09/12 09:53 AM

Well, now that the evil moon is arriving later, I can start to do some real compare and contrast evaluation with the Bino Box and BT100 as far as contrast of faint, extended objects such as dark nebulae.

My first impression is, all other things equal, mirrored binoculars will out perform prism binoculars because of the limitations of prisms (ie fingernail light leaks, ghost images, light scatter, etc.)

Wonder why we don't see three mirror binoculars available commercially.



There could be a potential market here...


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5309781 - 07/09/12 01:03 PM Attachment (162 downloads)

Bino Box and 6 inch f/5 Box refractor...

Post Extras: Print Post   Remind Me!   Notify Moderator  
Scanning4Comets
Markus
*****

Reged: 12/26/04

Loc: Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5325299 - 07/19/12 03:34 PM

Looks great Bill ! Very impressive!

Cheers,


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Scanning4Comets]
      #5335561 - 07/25/12 09:02 PM Attachment (100 downloads)

Interesting comparison....BT100s and (BBs) Bino Box.

Note difference in reflections.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5336262 - 07/26/12 09:45 AM

Some more notes...

Since one of the objective focal lengths is 3mm longer than the other, the eyepieces were sitting at different heights at the same diopter setting. This was not a problem with the 24mm Pans and the 14mm Denks as they have generous eye relief, but the 19mm Pans were a different story as the eye relief is tight and you have to put your eye socket up against the eyecups to see the fieldstop clearly.

I shimmed the long barrel between the lens cell flange and box. This brought the eps to the same height and made much more comfortable viewing through the 19mm Pans which are turning out to be my favorite ep with this binoscope.

The other thing I did was to cut off 3/4 inch of the helical focuser drawtube that was protruding into the box. This increased the edge of field illumination slightly,... every bit helps. I would estimate it to be about 80%.

The novelty of the scope has now worn off after several hours of use and I'm beginning to settle in and just look through them without all the fussing of initial adjustment.

This project has succeeded beyond my expectations and the binoscope has proven to be a serious, practical instrument for its intended use....examining Milky Way structure. The views are incredible on a transparent night such as last night and the detail is more like viewing a long exposure photograph than looking through optics.

Sorta makes the BT100s redundant....



Edited by Mr. Bill (07/26/12 06:36 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Wes James
Postmaster
*****

Reged: 04/12/06

Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5336335 - 07/26/12 10:38 AM

I've got to- once again- say "Congratulations" on a ground- breaking project here, Mr. Bill- truly a wonderful ATM project- not many people build their own bino's (Glenn LeDrew being one of the more noteworthy exceptions), and you took it in a different direction. Very, very nice. Color me envious!!
Wes


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Wes James]
      #5375918 - 08/19/12 01:04 PM Attachment (77 downloads)

Small improvement but makes finding target at zenith much easier on the neck...

Post Extras: Print Post   Remind Me!   Notify Moderator  
Jawaid I. Abbasi
Carpal Tunnel
*****

Reged: 06/19/07

Loc: LEVITTOWN, PA
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5375938 - 08/19/12 01:12 PM

Bill,
I am so impressed that now I am thinking to build but having lack of information and never built any binocular nor telescope; makes me think twice to start project. Money is also an issue and I do not want to put money into trash if not suceded.

Perhaps, I would ask you to build one in the future if you have time to permit you to build one.

One suggestion is that you should do a "petent" since I have not seen any binocular design like yours.

Regards,


Post Extras: Print Post   Remind Me!   Notify Moderator  
Rich V.
Post Laureate
*****

Reged: 01/02/05

Loc: Lake Tahoe area, Nevada, USA
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5375941 - 08/19/12 01:13 PM

There are times where I lusted for a finder mounted on half a broom handle! My back and neck can't stand up to the misery of "finder contortions" any more.

Well done, Bill!

Rich

BTW, how's the smoke lately? Looked pretty nasty the other day looking north towards your area....


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Jawaid I. Abbasi]
      #5376159 - 08/19/12 03:47 PM

Quote:

Bill,
I am so impressed that now I am thinking to build but having lack of information and never built any binocular nor telescope; makes me think twice to start project. Money is also an issue and I do not want to put money into trash if not suceded.

Perhaps, I would ask you to build one in the future if you have time to permit you to build one.

One suggestion is that you should do a "petent" since I have not seen any binocular design like yours.

Regards,




Building one was enough to test my patience....

Think I gave enough info in this thread that someone could build their own if they had a circular/radial arm saw and a drillpress and the time and money for parts (all available).

As far as a patent, it's not an original design and I don't think there's really anything to patent.

My amazement is that someone (as far as I know) hasn't done this design commercially as it is very practicable and avoids a lot of the problems of the porro prism design.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5376177 - 08/19/12 04:01 PM

One further thought....

I just bought a 99 year lease on an RV site and a 1/4 acre observatory site in southeast New Mexico.

http://www.granitegap.com/

How about a pair of 8 inch f/6 binoculars of the same design permanently mounted in a roll off roof observatory?



Edited by Mr. Bill (08/19/12 05:58 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jawaid I. Abbasi
Carpal Tunnel
*****

Reged: 06/19/07

Loc: LEVITTOWN, PA
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5376693 - 08/19/12 10:13 PM

You are right that no one has done it commercially and it will avoid problems. Perhaps cost effective if done commercially? just a thought.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Gordon Rayner
Carpal Tunnel
*****

Reged: 03/24/07

Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5379620 - 08/21/12 03:47 PM

You should have said southwest, rather than "southeast" New Mexico.

What about the summer "monsoon"? Driving west, toward Tucson, a few years ago, there was substantial instability and "heat lightning" after dark. Maybe that goes away later.
I slept in a truck , near the very busy Border Patrol station at Douglas,Az. after a rainstorm. There was an inspiring chorus of frogs , small and very large, who had just come out of estivation in the creekbed northeast of the station.

A friend, Robert Mortimer (RIP) retired south of Willcox,Az. and enjoyed dark skies, but heard and/or saw frequent Border Patrol-wetback/narcotic "mule" interaction near or on his land.

Did you consider the place run by the expat Canadian couple , near the road to the Mexican National Observatory at San Pedo Martir in Baja Calif., not far from the historic Meling-Johnson ranch?

To get more southern targets, yet retain the smooth, stable air of Baja, without the summer rain/hotel etc . gringo-ization-" development" and the resulting light pollution of the Cape region, what about the mid-peninsula.? But accessible altitudes with (rudimentary) shopping are lower there.

How does the finder relieve your neck for near-Zenith sighting? A high support, or a 90 degree reflecting mirror would help, but I see neither. ??


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Gordon Rayner]
      #5379662 - 08/21/12 04:16 PM

Right you are...meant to say southwest, near Lordsberg....actually Animas in Hidago county.

Have no desire to be there during summer/monsoon season; strictly use Oct-April.

Potential community of fellow astronomers.....price cheap enough if it doesn't work out no big deal.

As far as finder position, works for me. It gives an additional 2 inches of rise from original position.



Edited by Mr. Bill (08/21/12 04:27 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
kcolter
sage
*****

Reged: 06/04/03

Loc: Missouri, USA
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5425993 - 09/17/12 06:32 PM

.

]

How about a pair of 8 inch f/6 binoculars of the same design permanently mounted in a roll off roof observatory?






I'm curious about whether Bill, or Glenn, or any of the other talented ATMer's on the forum, see any problem trying to take Mr Bill's design up in size to 7 or 8 inch objectives? Weight will go up, obviously. What will it take to "deliver the images" to a spot where the diagonals can be made to place the eyepieces at an appropriate IPD? Will it take an extension tube between the two diagonals in order for the final diagonal to place the eyepieces at an appropriate IPD? Will a larger binobox mount need to be a yoke type altaz mount or could could the box still "hang on one side" of a mount the way Mr Bill has done with his bino box? There are probably many more issues that I haven't thought of.


Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: kcolter]
      #5426007 - 09/17/12 06:39 PM

Fundamentally, it's dead simple! Because of the larger separation required between bigger objectives, the first and second diagonal mirrors need to be scaled up in size so as to fully field the light cone. That's it; the rest is just making the construct to hold it all together.

Post Extras: Print Post   Remind Me!   Notify Moderator  
daniel_h
Carpal Tunnel
*****

Reged: 03/08/08

Loc: VIC, Australia
Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5426462 - 09/17/12 11:10 PM

did i miss the non moon report Bill - you said they make the BT redundant but did i miss some comparison?

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5427168 - 09/18/12 11:27 AM Attachment (68 downloads)

Actually, there is enough swing left in the present diagonals (9 inch total) that the same components, including the 3.1 inch mirrors, could be used on an 8 inch f/6 binoscope without compromising effective aperture/ field edge illumination.

I mention that size because APM offered 8 inch f/6 achromat lens sets....sadly it looks like they have been deleted from inventory.



Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: daniel_h]
      #5427199 - 09/18/12 11:42 AM

Quote:

did i miss the non moon report Bill - you said they make the BT redundant but did i miss some comparison?




Same weight (26 vs 30 lbs) with an impressive gain in image brightness and contrast because of larger aperture but also light scatter and transmission loss of porro prism vs dielectric mirrors. Also the Strehl of 97% and superior multicoatings of the Istar lensets has to help.

As I said earlier, it's like putting an image intensifier on the BT100s.

Also, field edge sharpness improved in the BinoBox.



Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5427568 - 09/18/12 02:39 PM

Another point worth mentioning....

I have read that a 5 inch rich field refractor will show the most number of stars in a starfield as a function of light grasp/real field of view.

I believe that my binobox is the best all around choice of aperture/f ratio, as well as weight/portability, when these factors are taken into account and used for viewing MW structure.

Bigger isn't always better....



Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5428066 - 09/18/12 07:04 PM

Bill,
The Richest Field Telescope is an interesting concept and subject. That such an instrument need not be large derives from the fact that at about the 11th magnitude, star numbers do not continue to increase as expected due to the combination of interstellar extinction near the band of the milky way and the fall-off in star density perpendicular to the galactic disk.

The instrument which, when operating at the largest useable exit pupil for the observer, just clearly shows stars to 11m, is The RFT. Under a dark sky, this would be an aperture of closer to 80mm, or even smaller for an experienced observer using a bino. At smaller exit pupils, or when the aperture is increased, the number of stars contained in the (same apparent) field of view decreases.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5428537 - 09/19/12 12:42 AM

Let's see....20x80 or 29x127? Hummm...



Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5428625 - 09/19/12 01:38 AM

Naturally, bigger is better if one desires to see more than merely the greatest number of stars possible at a time. And so one could legitimately ask, 29X127, or 50X200, or 100X400, or....? Ever larger is better for ever smaller *objects*. My point is that at a given exit pupil and apparent field of view, a 3" will show a larger number of discrete stellar points than will a 5", or an 8", or.... Not by a large margin, and not for *every* field examined, but in the main, yes.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5429003 - 09/19/12 10:47 AM

I wasn't disputing your statement about greatest number of stars seen in a MW field; I mentioned it because I had read somewhere the 5 inch refractor was optimal. It probably referred to fields examined without extinction coming into play. I looked through a few books on the shelf and couldn't locate the reference...I thought that Burnham or Clark had said it.

My Graemlin was ironically pointing out that maybe the greatest number of stars seen is not as important as the overall aesthetic of the field viewed.....I think the BinoBox hits a "sweet spot" in "enjoyability."



Post Extras: Print Post   Remind Me!   Notify Moderator  
Gordon Rayner
Carpal Tunnel
*****

Reged: 03/24/07

Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5429075 - 09/19/12 11:39 AM

The reference you seek is a chapter by Walkden(?) in ATM II or III , depending upon the date of publication . There is a picture of Leslie Peltier there, as I recall. If you have trouble finding the article , I can find it in those books.

It was written before WW II and the large numbers of big mounted binoculars which became available after that conflict, and before the 40% gain from a binocular was discovered/ published.

There was a revision to the original article which followed subsequent stellar population in relation to magnitude research.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Gordon Rayner]
      #5429366 - 09/19/12 02:47 PM

Quote:

The reference you seek is a chapter by Walkden(?) in ATM II or III , depending upon the date of publication . There is a picture of Leslie Peltier there, as I recall. If you have trouble finding the article , I can find it in those books.

It was written before WW II and the large numbers of big mounted binoculars which became available after that conflict, and before the 40% gain from a binocular was discovered/ published.

There was a revision to the original article which followed subsequent stellar population in relation to magnitude research.




I'm sure that I didn't read the original source...the info is second sourced in one of my shelf full of astro reference books.



Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: Gordon Rayner]
      #5429410 - 09/19/12 03:11 PM

Bill,
I know exactly what you're saying; for a 120mm bino of my own is on the horizon.

Gordon's memory serves him well, and I quickly looked over the chapter (the final one in the book) on the RFT in the original ATM 2. Author Walkden's original work was based on photographic magnitudes, for which the turnover in star density occurred at about 11m. The RFT aperture suggested was 2.75".

An addendum corrected things by use of then more recent data based on visual magnitudes. The star count turnover occurred at 12.4m, and so the RFT aperture was suggested as being 5".

My memory was based on the *original* study, forgetting that the magnitudes were photographic.

But for the individual, the instrument's efficiency, and depending on sky conditions, 'The' RFT is that which just shows stars at 12.4m when the maximum exit pupil is used.

Let's calculate this for myself. My out-of-town site typically allows me to just see to 6.4m naked eye. I need to gain 6 magnitudes in order to reach 12.4m. This is a brightness ratio of 2.512^6 = 251. And so my entrance pupil must be expanded so that its area is 251 times larger. That larger aperture equals the square root of 251 times 6.5, or 103mm.

Now, this is based in my two eyes being used to see those 6.4m stars. The RFT thus derived must necessarily apply to a binocular. A monocular RFT should be dimensioned so as to collect a further ~0.3m worth Of light in order to overcome the larger visual system noise imposed on a one-eyed view.

My binocular RFT is a 15.8X103.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: kcolter]
      #5431124 - 09/20/12 03:03 PM

Quote:



I'm curious about whether Bill, or Glenn, or any of the other talented ATMer's on the forum, see any problem trying to take Mr Bill's design up in size to 7 or 8 inch objectives? Weight will go up, obviously. What will it take to "deliver the images" to a spot where the diagonals can be made to place the eyepieces at an appropriate IPD? Will it take an extension tube between the two diagonals in order for the final diagonal to place the eyepieces at an appropriate IPD? Will a larger binobox mount need to be a yoke type altaz mount or could could the box still "hang on one side" of a mount the way Mr Bill has done with his bino box? There are probably many more issues that I haven't thought of.




Hi Kim

As far as mounting, I would use a yoke mount for a larger binobox.



Post Extras: Print Post   Remind Me!   Notify Moderator  
Wes James
Postmaster
*****

Reged: 04/12/06

Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5431198 - 09/20/12 03:46 PM

Quote:

My binocular RFT is a 15.8X103





Would love to see a pic(s) of this!!!


Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: Wes James]
      #5431211 - 09/20/12 03:53 PM

Wes,
That 'RFT for Glenn' configuration is merely the outcome of a calculation; it does not exist (at least as made by me)... I was merely illustrating how one could determine, based on their own pupil diameter and visual limiting magnitude, their personal RFT which will reveal the maximal number of stars in the FOV.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Wes James
Postmaster
*****

Reged: 04/12/06

Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5431429 - 09/20/12 06:20 PM

O.K., then- I'll change that to "I'd love to see a picture of that... in my backyard"!!

Wes


Post Extras: Print Post   Remind Me!   Notify Moderator  
Zoomit
sage


Reged: 12/04/06

Loc: Tehachapi, CA
Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5431656 - 09/20/12 08:46 PM

Quote:

A monocular RFT should be dimensioned so as to collect a further ~0.3m worth Of light in order to overcome the larger visual system noise imposed on a one-eyed view.





Glenn,

Slighly off-topic but do you have a handy reference for the 0.3m gain with binocular vision? Is that after correcting for light gathering area or before?


Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: Zoomit]
      #5432063 - 09/21/12 02:08 AM

Brandon,
The ~0..3m figure comes from the gain in signal to noise, which for two-eyed viewing equals the square root of two, or 1.414, or 41%. This is equivalent to 0.37 magnitude. But does one actually gain 0.37m in the faint star detection limit? The jury may not yet have arrived at a verdict. A gain of 0.2m would seem to be eminently realizable, and 0.3m quite possible. A matrix of variables might contribute to the actual gain.

In any event, when it comes to extended objects of low contrast, it is my sure impression that the gain is not inconsiderable, amounting to something like the 0.37m figure. The quality of the view, while numerically seeming to be small, is of no small consequence as regards the surety of detection of features near the limit of detection. How this translates to point sources has not been investigated in depth by yours truly (but it would be so easy to do!).


Post Extras: Print Post   Remind Me!   Notify Moderator  
planetmalc
sage


Reged: 10/21/09

Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5432598 - 09/21/12 12:11 PM

Quote:

My binocular RFT is a 15.8X103.




And the OG's would be working at around f1.4 'cos you'd be using the ES 9mm eyepiece with its 120-degree AFOV.......


Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: planetmalc]
      #5432789 - 09/21/12 02:02 PM

Is that a dig at my predilection, my proclivity, my penchant for ultra-wide fields? ;grin:

Post Extras: Print Post   Remind Me!   Notify Moderator  
Zoomit
sage


Reged: 12/04/06

Loc: Tehachapi, CA
Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5433337 - 09/21/12 07:40 PM

Quote:

Brandon,
The ~0..3m figure comes from the gain in signal to noise, which for two-eyed viewing equals the square root of two, or 1.414, or 41%. This is equivalent to 0.37 magnitude. But does one actually gain 0.37m in the faint star detection limit? The jury may not yet have arrived at a verdict. A gain of 0.2m would seem to be eminently realizable, and 0.3m quite possible. A matrix of variables might contribute to the actual gain.

In any event, when it comes to extended objects of low contrast, it is my sure impression that the gain is not inconsiderable, amounting to something like the 0.37m figure. The quality of the view, while numerically seeming to be small, is of no small consequence as regards the surety of detection of features near the limit of detection. How this translates to point sources has not been investigated in depth by yours truly (but it would be so easy to do!).




Thanks, Glenn. This is what I wanted to clarify. You're saying that going from a 5" monocular to a 5" binocular is equal to ~0.3m gain, or about equal to the effect from the increased light gathering area. In this case increasing the aperture from a 5" monocular (20 in^2) to either two 5" scopes or a single 7" scope (both 40in^2) yields an additional 0.3m.

[Edit: This is in error. A 7" mono yields 0.7m over a 5" mono.]

Edited by Zoomit (09/22/12 01:32 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
GamesForOne
professor emeritus


Reged: 09/29/09

Loc: Knoxville, TN
Re: 127mm f/5.5 binocular new [Re: Zoomit]
      #5433714 - 09/22/12 12:23 AM

Quote:


Thanks, Glenn. This is what I wanted to clarify. You're saying that going from a 5" monocular to a 5" binocular is equal to ~0.3m gain, or about equal to the effect from the increased light gathering area. In this case increasing the aperture from a 5" monocular (20 in^2) to either two 5" scopes or a single 7" scope (both 40in^2) yields an additional 0.3m.




Actually, there has been much discussion about this in past threads. The sqrt(2) multiplier should be applied to the area of one objective to get the equivalent area of a single objective. You do not simply add the areas of both bino objectives as binocular summation is not equivalent to a simple addition of the two areas.

When you apply a sqrt(2) increase to the area of one objective, the equivalent diameter multiplier works out to be 2^(1/4). Therefore, two 5" scopes using binocular summation are the theoretical equivalent of a 5" * 2^(1/4) = 5.9" single objective.

See the past discussion here.

---
Michael Mc


Post Extras: Print Post   Remind Me!   Notify Moderator  
planetmalc
sage


Reged: 10/21/09

Re: 127mm f/5.5 binocular new [Re: Zoomit]
      #5434204 - 09/22/12 10:58 AM

Quote:

Quote:

Brandon,
The ~0..3m figure comes from the gain in signal to noise, which for two-eyed viewing equals the square root of two, or 1.414, or 41%. This is equivalent to 0.37 magnitude. But does one actually gain 0.37m in the faint star detection limit? The jury may not yet have arrived at a verdict. A gain of 0.2m would seem to be eminently realizable, and 0.3m quite possible. A matrix of variables might contribute to the actual gain.

In any event, when it comes to extended objects of low contrast, it is my sure impression that the gain is not inconsiderable, amounting to something like the 0.37m figure. The quality of the view, while numerically seeming to be small, is of no small consequence as regards the surety of detection of features near the limit of detection. How this translates to point sources has not been investigated in depth by yours truly (but it would be so easy to do!).




Thanks, Glenn. This is what I wanted to clarify. You're saying that going from a 5" monocular to a 5" binocular is equal to ~0.3m gain, or about equal to the effect from the increased light gathering area. In this case increasing the aperture from a 5" monocular (20 in^2) to either two 5" scopes or a single 7" scope (both 40in^2) yields an additional 0.3m.




We do it for the sheer pleasure of using 2 eyes; the 0.3 mag gain is just a bonus.


Post Extras: Print Post   Remind Me!   Notify Moderator  
planetmalc
sage


Reged: 10/21/09

Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5434206 - 09/22/12 11:00 AM

Quote:

Is that a dig at my predilection, my proclivity, my penchant for ultra-wide fields? ;grin:




Oh yes - way to go, bro!


Post Extras: Print Post   Remind Me!   Notify Moderator  
Zoomit
sage


Reged: 12/04/06

Loc: Tehachapi, CA
Re: 127mm f/5.5 binocular new [Re: planetmalc]
      #5434437 - 09/22/12 01:13 PM

Quote:

We do it for the sheer pleasure of using 2 eyes; the 0.3 mag gain is just a bonus.




Your comment is actually at the heart of my inquiry. It goes beyond the summation discussion. I completely understand the "shear pleasure" of using 2 eyes and I'd like to quantity that effect. From an equivalent light gathering perspective, which correlates with cost, using two eyes yields about a 0.4m loss over an equal area monocular. [Using the examples above, a 5.9" scope gives up 0.4m to a 7" scope.]

What is it that motivates us to ignore the additional cost of using two eyes? Is there a way to quantify this? Probably should start a new thread...


Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: Zoomit]
      #5434638 - 09/22/12 03:17 PM

Brandon,
Binocular viewing incurrs a *cost*? Quite the contrary; it affords a *gain*. And the equivalence is: a 5" bino about equals a 5.9" singleton.

But to me this 'aperture equivalence' is academic, and belongs only in the sphere of the theoretical. In the real world, the 5" bino is a 5" aperture instrument which allows the most efficient use of our two eyes. If anything, when bandying about this aperture equivalence thing, it's more realistic to state that a 5" telescope is actually closer to a 4.2" binocular! Squinting with one eye is an unnecessary handicap to be avoided. That's how binoculars should be promoted!


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5434649 - 09/22/12 03:31 PM

Quote:

Brandon,
Binocular viewing incurrs a *cost*? Quite the contrary; it affords a *gain*. And the equivalence is: a 5" bino about equals a 5.9" singleton.

But to me this 'aperture equivalence' is academic, and belongs only in the sphere of the theoretical. In the real world, the 5" bino is a 5" aperture instrument which allows the most efficient use of our two eyes. If anything, when bandying about this aperture equivalence thing, it's more realistic to state that a 5" telescope is actually closer to a 4.2" binocular! Squinting with one eye is an unnecessary handicap to be avoided. That's how binoculars should be promoted!






Post Extras: Print Post   Remind Me!   Notify Moderator  
Zoomit
sage


Reged: 12/04/06

Loc: Tehachapi, CA
Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5435032 - 09/22/12 08:14 PM

Quote:

Brandon,
Binocular viewing incurrs a *cost*? Quite the contrary; it affords a *gain*.

//cut//

Squinting with one eye is an unnecessary handicap to be avoided. That's how binoculars should be promoted!




Oh come on, there's huge premium for a binocular view, as we're all aware. To most people, that incremental pleasure from a binocular view cannot justify the significant additional expense and complexity. That's why most telescopes, even those intended to be only visual instruments, remain monocular.

Even in refractor vs newt vs SCT debates, there are quantitative comparison data and arguments. I've tried to logically justify a binocular view but the argument always seems to boil down to: two eyes are better than one.

Which is where I started when I posed my original question (and with apologies to Mr. Bill, the OP, for taking the thread down this path). I was hoping Glenn had a quantitative metric that captured the "sheer pleasure" of a binocular view, beyond the straightforward summation equations.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Zoomit]
      #5435086 - 09/22/12 08:53 PM

As the OP, it seems appropriate that a new thread be started on the topic of "cost vs. benefit of binocular vision compared with monocular vision."

Certainly this discussion has gone astray from the construction and use of my BinoBox.



Post Extras: Print Post   Remind Me!   Notify Moderator  
RodgerHouTex
Pooh-Bah
*****

Reged: 06/02/09

Loc: Houston, Texas, USA
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5435660 - 09/23/12 08:47 AM

Okay, back to your binobox. How is the chromatic aberration? I'm pretty sensitive to that with a telescope, but don't notice it much in my binos. Is it because of the lower magnifications involved?

I'm toying with the idea of using a pair of the 6" Istar f/5 objectives to make a binobox. I'm also concerned about field curvature in an f/5 objective. How is the field curvature in yours?

Thanks,


Post Extras: Print Post   Remind Me!   Notify Moderator  
JKoelman
professor emeritus


Reged: 05/16/11

Loc: Bangalore, India
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5435747 - 09/23/12 09:44 AM

Quote:

My amazement is that someone (as far as I know) hasn't done this design commercially as it is very practicable and avoids a lot of the problems of the porro prism design.




These guys seem to be commercializing a 3 mirror design: http://www.astro-mechanik.de/doppelfernrohre.htm


Post Extras: Print Post   Remind Me!   Notify Moderator  
Rich V.
Post Laureate
*****

Reged: 01/02/05

Loc: Lake Tahoe area, Nevada, USA
Re: 127mm f/5.5 binocular new [Re: JKoelman]
      #5435945 - 09/23/12 11:43 AM

Yes, that was also the approach used in the Astromeccanica/Borg binoscope reviewed by Milt Wilcox eight years ago.

Rich


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: RodgerHouTex]
      #5435958 - 09/23/12 11:48 AM Attachment (26 downloads)

Quote:

Okay, back to your binobox. How is the chromatic aberration? I'm pretty sensitive to that with a telescope, but don't notice it much in my binos. Is it because of the lower magnifications involved?

I'm toying with the idea of using a pair of the 6" Istar f/5 objectives to make a binobox. I'm also concerned about field curvature in an f/5 objective. How is the field curvature in yours?




Good question...I have both the Istar 6 inch f/5 lens set (in a MonoBox design I did last year) and of course the 5 inch f/5.5 lens sets.

Not overly impressed with CA and field curvature in the 6 inch....the 5 inch lens sets are much better in both parameters. Stars are pinpoint using Panoptics out to 90% of edge of field in 5 inch.

Actually, my Celestron (Synta) 6 inch f/5 shows a much better image than the Istar 6 inch, so the Istar's shortcomings go beyond the laws of physics.

However, for magnifications under 75x, the 6 inch f/5 objectives would do a good job for scanning MW fields.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: JKoelman]
      #5435978 - 09/23/12 12:00 PM

Looks to me they just stack 2 inch diagonals. I have to wonder about vignetting even at f/7.

My design uses a 3.1 inch mirror as the first element and by careful raytracing gives over 70% edge of field illumination and of course full effective aperture.

My comment about this design not being commercially available really refered to a fully integrated binocular....not just hanging diagonals on two telescopes.

Edited by Mr. Bill (09/23/12 12:45 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5436518 - 09/23/12 04:50 PM

I wondered also about the vignetting and potential aperture loss incurred by having to push the focuser drawtube farther inward along the optical path when additional diagonals are attached at the back end...

A system designed from the ground up will be better in these respects.


Post Extras: Print Post   Remind Me!   Notify Moderator  
RodgerHouTex
Pooh-Bah
*****

Reged: 06/02/09

Loc: Houston, Texas, USA
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5437869 - 09/24/12 11:07 AM

Thanks Mr. Bill. I think you may have saved me from a very expensive mistake with the 6" Istar.

And the 6" f/5 Celestron (Synta) you're talking about is the Newtonian right?


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: RodgerHouTex]
      #5437908 - 09/24/12 11:33 AM Attachment (40 downloads)

No....that would be comparing apples and oranges.

It's a two element achromat just like the Istar.

Here's a picture of the two comparing coatings.

Not meaning to discourage you....for binoculars I think the Istar 6 inch f/5 lens sets would be fine....I chose to use the 5 inch f/5.5 lens set for mine because of size/weight considerations.


Post Extras: Print Post   Remind Me!   Notify Moderator  
RodgerHouTex
Pooh-Bah
*****

Reged: 06/02/09

Loc: Houston, Texas, USA
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5437960 - 09/24/12 11:59 AM

Okay then I'm wondering where are the Celestron/Synta lenses available. When I did a search, I just came up with the 6" f/5 Newt.

Thanks,


Post Extras: Print Post   Remind Me!   Notify Moderator  
Rich V.
Post Laureate
*****

Reged: 01/02/05

Loc: Lake Tahoe area, Nevada, USA
Re: 127mm f/5.5 binocular new [Re: RodgerHouTex]
      #5437988 - 09/24/12 12:15 PM

Rodger, here's the 6" f5 refractor:

Celestron Omni XLT 6" refractor

Don't see it available as an OTA only, though.

Rich


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: RodgerHouTex]
      #5437993 - 09/24/12 12:17 PM

I think you would have to buy two OTAs. Might make an interesting project using their tubes.

You could shorten the tubes to accomodate the relay mirror.

Frankly, I would go with the Istars...just remember that no matter what, short focus achromats will never give you good high magnification images.

The most I use on the Celestron is a 10mm Ethos which yields 75x. After that, the image degrades rapidly.

Just noticed from Celestron ad copy that the lens is aspheric....that would account for superior spherical aberration correction.


Post Extras: Print Post   Remind Me!   Notify Moderator  
RodgerHouTex
Pooh-Bah
*****

Reged: 06/02/09

Loc: Houston, Texas, USA
Re: 127mm f/5.5 binocular new [Re: Rich V.]
      #5438122 - 09/24/12 01:39 PM

Thanks for the link Rich. Yea, buying two telescopes at $829 is probably not in my future. I do like the concept of Mr. Bill's bino box though so I just need to decide what to put in it. It might just be the Istar 127mm lenses that he used.

Post Extras: Print Post   Remind Me!   Notify Moderator  
RodgerHouTex
Pooh-Bah
*****

Reged: 06/02/09

Loc: Houston, Texas, USA
Re: 127mm f/5.5 binocular new [Re: RodgerHouTex]
      #5438127 - 09/24/12 01:41 PM

I'm not really looking for high mags Mr. Bill. I do want a 4 to 5 mm. exit pupil though. So whatever I end up with I'll just have to pick the right eyepiece.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: RodgerHouTex]
      #5438158 - 09/24/12 02:00 PM

I use and highly recommend the 24mm and 19mm Panoptics.



Post Extras: Print Post   Remind Me!   Notify Moderator  
Collimator
super member


Reged: 09/05/12

Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5438205 - 09/24/12 02:26 PM

Sorry, but I am new to this.
Can someone direct me to reviews of the Vixen 125mm binocular telescope.
I think there may be 8 different eyepiece sets.

My RFT made in the 1970s contains a very good coated 5 1/8 inch f/5 Jaegers achromat, which I asked them to select specially. I think it was a cemented doublet in Jaegers own cell. The clear aperture was 123mm.
It performed beautifully for many years in a custom telescope I had made.
The magnifications were 16x with a Kodak WW2 EWA coated eyepiece. Almost 5 degree field. 3 inch eyepiece holder.
20x with 32mm 2 inch Erfle.
35x with 18mm 75 degree eyepiece uncoated.
75x with 8mm Edmunds RKE which is a wonderful combination.
145x with 4.3mm Swift Ortho unfortunately found to be radioactive later.
At 145x this magnification was fully useful and reached mag. 13.1 in town.
So I presume there must be other reasons why using two of these 145x eyepieces would not give good results in a binocular telescope.
And 210x with a 3mm Clave eyepiece. This was a little too much but still usable.

Edited by Collimator (09/24/12 02:29 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Collimator]
      #5594778 - 12/29/12 05:43 PM Attachment (79 downloads)

Well, looks like the BinoBox will be featured in S&T this spring in Gary Seronik's Telescope Workshop column....

A picture from the "photoshoot."


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mark9473
Postmaster
*****

Reged: 07/21/05

Loc: 51°N 4°E
Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5594815 - 12/29/12 06:05 PM

Congratulations Mr. Bill; looking forward to the article.

Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: Mark9473]
      #5594889 - 12/29/12 06:45 PM

Good on ya, mate! I look forward to reading this one.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5602852 - 01/03/13 12:01 PM

According to Gary, looks like April S&T for article... that means it will appear at the end of Feb, beginning of March.



Post Extras: Print Post   Remind Me!   Notify Moderator  
faackanders2
Carpal Tunnel


Reged: 03/28/11

Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5606911 - 01/05/13 04:20 PM

Congrats! How is the view?

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: faackanders2]
      #5606925 - 01/05/13 04:30 PM

Right now, overcast, but on a good night my skies are green/blue. SQMs of 21.5 on best nights.



Post Extras: Print Post   Remind Me!   Notify Moderator  
faackanders2
Carpal Tunnel


Reged: 03/28/11

Re: 127mm f/5.5 binocular new [Re: Zoomit]
      #5607141 - 01/05/13 06:46 PM

Quote:

Quote:

Brandon,
Binocular viewing incurrs a *cost*? Quite the contrary; it affords a *gain*.

//cut//

Squinting with one eye is an unnecessary handicap to be avoided. That's how binoculars should be promoted!




Oh come on, there's huge premium for a binocular view, as we're all aware. To most people, that incremental pleasure from a binocular view cannot justify the significant additional expense and complexity. That's why most telescopes, even those intended to be only visual instruments, remain monocular.

Even in refractor vs newt vs SCT debates, there are quantitative comparison data and arguments. I've tried to logically justify a binocular view but the argument always seems to boil down to: two eyes are better than one.

Which is where I started when I posed my original question (and with apologies to Mr. Bill, the OP, for taking the thread down this path). I was hoping Glenn had a quantitative metric that captured the "sheer pleasure" of a binocular view, beyond the straightforward summation equations.




Joy is subjective (like why some like 100AFOV or not). Thos with large telesopes can get a taste with binoviewers, but this normally comes at the expense of higher power and less light to each eye. Small binoculars provide much wider TFOVs than telescopes. Large binos still provide wider FOV than binoviewers. They are complimentary, and don't need to be exclusive.


Post Extras: Print Post   Remind Me!   Notify Moderator  
EricP
sage


Reged: 11/09/07

Loc: Sachse, Texas
Re: 127mm f/5.5 binocular new [Re: faackanders2]
      #5607405 - 01/05/13 10:22 PM

That's awesome news, Bill! Congrats on making your mark in S&T. Looking forward to the article.

Post Extras: Print Post   Remind Me!   Notify Moderator  
planetmalc
sage


Reged: 10/21/09

Re: 127mm f/5.5 binocular new [Re: EricP]
      #5615531 - 01/10/13 01:22 PM

Mr Bill's design raises an intriguing possibility. Instead of fixing the mount to the side of the box, attach it instead to the BOTTOM. This allows the instrument to swing through a 180-degree arc from horizon to horizon via the zenith. If the OG's are spaced around 9" apart and the 1.25" diagonals have a small footprint, then the two diagonal arms can ALWAYS be swung to a position whereby the observer (probably seated) can look horizontally into the eyepieces with his head upright, and only small sideways movements of the head are needed to cater for objects at various declinations. In essence, the observer's position is extremely comfortable and fixed (until a significant change in RA is required).

Get the cardboard, scissors and drawing pins out and prove it for yourself!

Edited by planetmalc (01/10/13 01:51 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: planetmalc]
      #5615631 - 01/10/13 02:22 PM

I don't see this as possible at all... I take it you mean the bino is now oriented such that when pointed toward the horizon, one objective lies directly above the other, effectively having the instrument lying on what would currently be considered the side.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5615667 - 01/10/13 02:45 PM Attachment (34 downloads)

The alternate position for positioning the diagonals puts eps much closer to the altitude axis so the swing from horizon to zenith is minimized.

I tried both and prefer the diagonals and ep further back as I generally observe standing and don't like leaning over the binos...


Post Extras: Print Post   Remind Me!   Notify Moderator  
planetmalc
sage


Reged: 10/21/09

Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5617178 - 01/11/13 12:23 PM

Quote:

I don't see this as possible at all... I take it you mean the bino is now oriented such that when pointed toward the horizon, one objective lies directly above the other, effectively having the instrument lying on what would currently be considered the side.



Exactly (and firstly, may I apologise for leaving the word 'sideways' in my original post; it should have been edited out).

Starfields don't have a 'proper orientation' (if so, they'd be 'upside down' in an absolute sense in the southern hemisphere) so it matters not a jot what their actual orientation is when you observe them - OK, it might be unfamiliar, and require star atlases to be rotated, but it wouldn't be 'wrong'. I accept that it seems less 'right' to do this with a binocular than it does with a telescope because we normally use bins with their OG's parallel to the horizon, but whilst this is a necessity in terrestrial use it is irrelevant for astronomy (asymmetric binoculars are an example of this).

There can't be many knowledgable 'scope users who haven't thought, "I'd love a Springfield mount", because having the fixed observing position is just SO convenient, but they're complicated and probably not compatible with low magnification/wide field aspirations. Designing a Springfield-mount binocular would be a nightmare, but if you use large bins and want your observing position to be as static as possible - and are prepared to compromise by accepting that you could enjoy a 'Springfield effect' for objects at ANY declination, but ONLY across a small-ish range of RA - then surely this would be worth going for. I envisage a seated observer, using a bottom-mounted Mr. Bill design, sitting side-on to whatever he is observing (we already do this with Newtonian telescopes), with his head ALWAYS held in its natural position (upright and with the eyes looking parallel to the ground), observing an object at ANY declination through an arc of 180 degrees, with only small movements of the head being required to compensate for changes in declination. As I said in my original post, if the (principal axes of the) OG's are around 9" apart, and the instrument is bottom-mounted, and the 1.25" diagonals have a small footprint, then for diagonals arms whose diagonals have their centres 4.5" apart (as per Mr Bill's layout in post #1), it is ALWAYS possible to orient the diagonal arms so that horizontally-aligned eyepieces are presented to the observer with the correct IPD (you really have to make a life-size scale model of the system to see the complex geometry that's going on when you swing the diagonal arms around - it's not something you can visualize). The eyepiece position (compared to a fixed datum) DOES move a little (both vertically and horizontally) for changes in declination, but can be compensated for - even if the observer is seated in a fixed-height chair - by slight changes in posture. The observer only ever needs to significantly alter the position of his head when he gets up to move his seat so that he can observe another object which has an appreciably different RA.

If you think about it, when forum members are discussing the relative merits of straight-through, 45-degree or 90-degree eyepiece inclinations (and bemoaning the fact that the preferred 90-degree option usually comes with reduced-aperture problems) then we're really talking about keeping head position as natural as possible, to reduce fatigue; the bottom-mounted Mr. Bill instrument achieves this and all the design work has been done.

Edited by planetmalc (01/11/13 12:42 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
planetmalc
sage


Reged: 10/21/09

Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5617192 - 01/11/13 12:30 PM

Quote:

The alternate position for positioning the diagonals puts eps much closer to the altitude axis so the swing from horizon to zenith is minimized.

I tried both and prefer the diagonals and ep further back as I generally observe standing and don't like leaning over the binos...



Leaning is NEVER required if you use the bottom-mounted system, Bill.

Edited by planetmalc (01/11/13 12:45 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Rich V.
Post Laureate
*****

Reged: 01/02/05

Loc: Lake Tahoe area, Nevada, USA
Re: 127mm f/5.5 binocular new [Re: planetmalc]
      #5617276 - 01/11/13 01:20 PM

I understand your point, Planetmalc, keeping the eyepieces near and in line with the alt axis limits the viewer's movement for a single eyepiece but with the BinoBox it seems fiddly to have to keep re-setting the diagonals to maintain a relatively level viewing position and still achieve proper IPD from low to high viewing angles.

You've essentially changed the neck motion from up/down to right/left lean. To keep the right/left lean minimal, you'd have to be adjusting the swing of the diagonals frequently.

Unless I had a real neck mobility issue, the standard alt/az orientation with 90° viewing is pretty comfortable for me, whether it's an angled bino or a telescope/diagonal.

For many of us, I think, the familiar up/down orientation of the sky in binoculars (even if L/R reversed in this case) makes moving the bino or scope towards a target more intuitive. YMMV, of course.

Rich


Post Extras: Print Post   Remind Me!   Notify Moderator  
Gordon Rayner
Carpal Tunnel
*****

Reged: 03/24/07

Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5617865 - 01/11/13 07:39 PM

Looking at Mr. Bill's picture of his mount, above, gave the following construction insight(?) , unrelated to the mount motions:

A "D" size long dovetail pair from ADM, or Losmandy, or other suppliers of mounting quick-release dovetails, could be milled and/or bored and/or bandsawn and then hand filed, to have a large racetrack shaped, or rectangular, opening. This would be the basis for a linear IPD motion of one 2-mirror "prism", to gain an erect image with only two mirrors.

One roof mirror "prism" , fixed to a segment of dovetail, either male or female,would move laterally on a much longer piece of dovetail of the opposite gender. Another segment would hold the other "prism", which would have no lateral IPD motion. It would be fed via a circular or square opening near the racetrack shaped opening.

The eyepiece fed by the moving "prism" would be moved laterally by twice the lateral motion of its "prism". The motions could be 2:1 linked, as in WW II Zeiss 25 x 100 or 12 x 60, 25 &40 x 200, and others, for real-time synchronization.

Or, the 2:1 motion could be set by an observer who is the usual, or only, user, without linkage, to simplify construction.

ADDENDUM 1/13/13 :

Two ADM DUP7M, or comparable offerings from others, bolted together back-to-back ( available bolted from ADM), would form the structural core. The lower, inner DUP7, facing the inside of the box body, would hold each of the roof mirror pair "prisms", one of which would be laterally slidable .

The upper, outside the box DUP7 would hold the female eyepiece carriers, one of which would be laterally movable .

Suitable openings would be made as described.

Edited by Gordon Rayner (01/13/13 01:58 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
Re: 127mm f/5.5 binocular new [Re: Gordon Rayner]
      #5617883 - 01/11/13 07:49 PM

Hey Gordon

I did this with a radial arm saw and a floor drillpress....

if I had a machine shop I could have been more inventive.



Post Extras: Print Post   Remind Me!   Notify Moderator  
ronharper
Carpal Tunnel
*****

Reged: 02/14/06

Re: 127mm f/5.5 binocular new [Re: Mr. Bill]
      #5618336 - 01/12/13 12:55 AM

That is awesome Mr. Bill. An original and versatile design, and nice work. Your talent and the thing itself are both enviable.
Ron


Post Extras: Print Post   Remind Me!   Notify Moderator  
planetmalc
sage


Reged: 10/21/09

Re: 127mm f/5.5 binocular new [Re: Rich V.]
      #5618837 - 01/12/13 11:18 AM

Quote:

I understand your point, Planetmalc, keeping the eyepieces near and in line with the alt axis limits the viewer's movement for a single eyepiece but with the BinoBox it seems fiddly to have to keep re-setting the diagonals to maintain a relatively level viewing position and still achieve proper IPD from low to high viewing angles.

You've essentially changed the neck motion from up/down to right/left lean. To keep the right/left lean minimal, you'd have to be adjusting the swing of the diagonals frequently.




Rich: when I modelled it in cardboard - the ONLY way to see what's really going on - I joined the centres of the 'eyepieces' together with a tie-bar and drawing pins, with the distance between the two drawing pins being equal to my IPD. The two cardboard 'diagonal arms' then swing as a single unit with the IPD being maintained, and the process seems completely natural because there's only one possible position the unit can be swung to if you want the eyepieces to end up precisely horizontal (not a necessity of course, but probably the orientation that most observers would go for). This is obviously simpler than adjusting the relative positions of two real diagonal arms on a real instument, but if I was making a binocular like this - and I just might - then I'd probably try to fashion some kind of tie-bar on the actual instrument itself (shaped like a o--o, with the ring-shaped bits around an exposed section of the 1.25" tubes that slide into the focuser). It might eventually prove not to work, but I'd sure try it! The big problem that I forsee would be the one that Mr. Bill encountered: insufficient friction in the pivoting bits. I could use Mr. Bill's remedy, but there'd be so much more diagonal arm-swinging in my system that I think this particular area might require frequent maintenance.

The amount of vertical/horizontal head movement required to compensate for changes in declination can be reduced to a minimum by attaching the bino-box to the mount at an optimum point that needs to be determined by pre-modelling in cardboard - it is NOT where you'd intuitively expect it to be!

Quote:

For many of us, I think, the familiar up/down orientation of the sky in binoculars (even if L/R reversed in this case) makes moving the bino or scope towards a target more intuitive. YMMV, of course.




I agree entirely, but I think I'd eventually get used to the bottom-mounted system (and if I couldn't, I could always convert it to side-mount). The type of finder used could be crucial here: I think I'd want a correct-orientation image, so I'd probably have to have (say) a low-power rifle scope with its long eye-relief allowing the use of a small pentaprism between scope & eye. Annoyingly, this would completely go against the concept of minimal head movement.

Edited by planetmalc (01/12/13 12:31 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: 127mm f/5.5 binocular new [Re: planetmalc]
      #5619609 - 01/12/13 06:33 PM

I've just sketched out the geometry of the independently rotating eyepiece assemblies, and can see that in principle one should be able to devise a scheme which will allow to keep the eyepieces oriented horizontally as the bino is swung in altitude while 'lying on its side.'

This arrangement requires that the mechanical dimensions be such that the swinging arms do not interfere with each other, and at first examination may make it difficult to build for the 2" eyepiece format. This also seems to require a relatively close observance of the ratio of objective separation to radius of swing of the eyepieces.

When the altitude axis coincides with the middle of the eyepiece pair's range of motion, the required vertical head movement is quite minimal. To get the pivot point moved rearward to the required degree and regain balance, it requires only to have a counterweight on a bar extending rearward, as part of the mount, said bar doubling as a handle.

An idea which has merit!


Post Extras: Print Post   Remind Me!   Notify Moderator  
planetmalc
sage


Reged: 10/21/09

Re: 127mm f/5.5 binocular new [Re: GlennLeDrew]
      #5622483 - 01/14/13 11:17 AM

Quote:

I've just sketched out the geometry of the independently rotating eyepiece assemblies, and can see that in principle one should be able to devise a scheme which will allow to keep the eyepieces oriented horizontally as the bino is swung in altitude while 'lying on its side.'




I'm impressed; I had to build a life-size cardboard model to figure all this out!


Quote:

This arrangement requires that the mechanical dimensions be such that the swinging arms do not interfere with each other, and at first examination may make it difficult to build for the 2" eyepiece format. This also seems to require a relatively close observance of the ratio of objective separation to radius of swing of the eyepieces.




Indeed. Even the footprint of the splendid Stellarvue 1.25" units that Mr. Bill has used might be too much for observers with narrow IPD's - it's those protruding corners that cause all the trouble. There's no doubt that people who have widely-spaced eyes could be much more cavalier in their choice of the 3rd diagonal. Someone, somewhere makes a 2" diagonal with a circular - rather than square - footprint, but I can't remember the name of the brand. A bit of serendipity might be all that's needed to make their use feasible.




Edited by planetmalc (01/16/13 12:00 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | (show all)


Extra information
12 registered and 36 anonymous users are browsing this forum.

Moderator:  Greyhaven, Knuklhdastrnmr, WOBentley 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled


Thread views: 14775

Jump to

CN Forums Home


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics