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127mm f/5.5 binocular

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#101 Mr. Bill

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Posted 07 July 2012 - 05:22 PM

Post deleted by Mr. Bill

#102 Refractor6

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Posted 07 July 2012 - 06:41 PM

Awesome project Mr. Bill!!! :cool: :bow: :bow:

#103 GlennLeDrew

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Posted 08 July 2012 - 12:10 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.

#104 Mr. Bill

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Posted 08 July 2012 - 02:11 PM

Just for you Glenn...

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

:grin:

#105 Mr. Bill

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Posted 09 July 2012 - 08:41 AM

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

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  • 5309482-Parts list Bino Box.JPG


#106 Mr. Bill

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Posted 09 July 2012 - 08:53 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.

:question:

There could be a potential market here... :cool:

#107 Mr. Bill

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Posted 09 July 2012 - 12:03 PM

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

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#108 Scanning4Comets

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Posted 19 July 2012 - 02:34 PM

Looks great Bill ! Very impressive! :bigshock: :bow:

Cheers,

#109 Mr. Bill

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Posted 25 July 2012 - 08:02 PM

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

Note difference in reflections.

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  • 5335561-BB vs BT.JPG


#110 Mr. Bill

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Posted 26 July 2012 - 08:45 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....

:cool:

#111 Wes James

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Posted 26 July 2012 - 09:38 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

#112 Mr. Bill

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Posted 19 August 2012 - 12:04 PM

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

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#113 Jawaid I. Abbasi

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Posted 19 August 2012 - 12:12 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,

#114 Rich V.

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Posted 19 August 2012 - 12:13 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! :waytogo:

Rich

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

#115 Mr. Bill

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Posted 19 August 2012 - 02:47 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,


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

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.

#116 Mr. Bill

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Posted 19 August 2012 - 03:01 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?

:bigshock:

#117 Jawaid I. Abbasi

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Posted 19 August 2012 - 09:13 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.

#118 Gordon Rayner

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Posted 21 August 2012 - 02:47 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. ??

#119 Mr. Bill

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Posted 21 August 2012 - 03:16 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.

:cool:

#120 kcolter

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Posted 17 September 2012 - 05:32 PM

.

]

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

:bigshock: [/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.

#121 GlennLeDrew

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Posted 17 September 2012 - 05:39 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.

#122 daniel_h

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Posted 17 September 2012 - 10:10 PM

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

#123 Mr. Bill

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Posted 18 September 2012 - 10:27 AM

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.

:p

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#124 Mr. Bill

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Posted 18 September 2012 - 10:42 AM

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.

:cool:

#125 Mr. Bill

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Posted 18 September 2012 - 01:39 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....

:cool:


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