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 | (show all)
Mr. Bill
Postmaster
*****

Reged: 02/09/05

Loc: Northeastern Cal
"new" 70mm 45s
      #5605333 - 01/04/13 06:23 PM

Just found these on Big Binocular website.

http://www.bigbinoculars.com/70bt45.htm

Anybody with first hand knowledge?

Didn't 90 degree versions have effective aperture and edge of field illumination issues?



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

Reged: 01/02/05

Loc: Lake Tahoe area, Nevada, USA
Re: "new" 70mm 45s new [Re: Mr. Bill]
      #5605482 - 01/04/13 08:01 PM

Quote:

Didn't 90 degree versions have effective aperture and edge of field illumination issues?






It was the 100mm 90° that had effective aperture problems and considerable vignette. The MKII version of the Garrett 70mm measured full aperture, IIRC. Don't know about the illumination of field, though.

There was a long thread a while ago about these:

Garrett BT70-90 MK II's arrived!

Still looking for the reference to the flashlight aperture test; maybe it was another thread...Searching CN can be a pain sometimes!

Rich


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

Reged: 03/08/08

Loc: VIC, Australia
Re: "new" 70mm 45s new [Re: Rich V.]
      #5605618 - 01/04/13 09:42 PM

i think i remember 68mm being quoted, it was close (i agree searching CN is a pain-the lists can be huge)

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


Reged: 09/29/09

Loc: Knoxville, TN
Re: "new" 70mm 45s new [Re: Rich V.]
      #5606249 - 01/05/13 10:19 AM

Quote:

Quote:

Didn't 90 degree versions have effective aperture and edge of field illumination issues?






It was the 100mm 90° that had effective aperture problems and considerable vignette.





Not meaning to get off-topic, but we do have one poster who recently purchased a 100mm 90° model direct from the Chinese factory and it tests at very near full aperture with the appearance of good field illumination to the edges.

I don't know if/when this model will propagate to dealers such as Garrett and Orion, but it appears the shortcomings have been addressed at least in the one sample that has been reported.

---
Michael Mc


Post Extras: Print Post   Remind Me!   Notify Moderator  
peter k
sage


Reged: 02/03/07

Re: "new" 70mm 45s new [Re: daniel_h]
      #5608451 - 01/06/13 01:59 PM

Yes. approximately 68mm effective aperture on the 90s (link to my original post).

I believe the 45-degree version has been on the United Optics web site for years--just no US distributors until now.


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


Reged: 01/24/07

Re: "new" 70mm 45s new [Re: peter k]
      #5609890 - 01/07/13 10:33 AM

Beautiful optics.. attention to the inter-pupil distance 68 mm max (my eyes are almost 70 mm),hope that as soon as possible this small problem is modified.

Edited by STEEL (01/07/13 10:35 AM)


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

Reged: 01/02/05

Loc: Lake Tahoe area, Nevada, USA
Re: "new" 70mm 45s new [Re: STEEL]
      #5609958 - 01/07/13 11:02 AM

Good point, Steel, I hadn't noticed the 68mm max. IPD spec for these...

Rich


Post Extras: Print Post   Remind Me!   Notify Moderator  
OBERWERK
Vendor
*****

Reged: 06/24/03

Loc: OH
Re: "new" 70mm 45s new [Re: Rich V.]
      #5610072 - 01/07/13 12:01 PM

Quote:

Good point, Steel, I hadn't noticed the 68mm max. IPD spec for these...

Rich




True, and we'll soon change that. In the mean time, there is an IPD linkage stop that can be easily removed to gain additional width. The binocular's handle then acts as the new stop, and it will then go to 78mm.


Post Extras: Print Post   Remind Me!   Notify Moderator  
kray1
member


Reged: 06/22/10

Loc: NC
Re: "new" 70mm 45s new [Re: OBERWERK]
      #5610400 - 01/07/13 03:05 PM

I have the 25 x 100 Garrett and the 15 x 70 Oberwerk; would the 70mm/45 binocular telescope really add that much to my viewing experience?
If so, what addtional magnifications be most beneficial for this bino?


Post Extras: Print Post   Remind Me!   Notify Moderator  
OBERWERK
Vendor
*****

Reged: 06/24/03

Loc: OH
Re: "new" 70mm 45s new [Re: kray1]
      #5610455 - 01/07/13 03:39 PM

Quote:

I have the 25 x 100 Garrett and the 15 x 70 Oberwerk; would the 70mm/45 binocular telescope really add that much to my viewing experience?
If so, what additional magnifications be most beneficial for this bino?



The image quality is exceptional, very sharp at 47x (8mm eyepieces). The combination of versatility and high quality, in a small relatively-lightweight (8.5 lb.) package is quite unique.


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

Reged: 02/09/05

Loc: Northeastern Cal
Re: "new" 70mm 45s new [Re: OBERWERK]
      #5610496 - 01/07/13 04:09 PM

Not to mention 45 degree oculars which are very desirable for those of us that spend most of our binocular time looking up....

Kevin...meant to ask, what is the prism clear aperture?

Am I going to vignette my 24 Pans with a 27mm fieldstop?

I think I remember 22mm being mentioned for the 90s.



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

Reged: 01/02/05

Loc: Lake Tahoe area, Nevada, USA
Re: "new" 70mm 45s new [Re: kray1]
      #5610525 - 01/07/13 04:21 PM

Kray, you're pretty well set for wide field views. A 70mm BT would give you a range from 16x to maybe 50x. Your current large binos at 25x@ 2.5° and 15x@ 4° already cover the lower mags a 70mm BT would provide. The only gain would be in the 25-50x range but I think for the sake of avoiding redundancy, a 100mm BT would be more appropriate with its 25x-75x mag. range. If you only want to travel with one multi-purpose instrument, though, a 70mm BT might just be the ticket.

BTs have a big advantage over straight-through bino designs in their viewing comfort. You can sit comfortably and look through the angled eyepieces all the way to zenith; try that without some kind of p-gram or chair mount with your 25x100s.

A binocular telescope gives you the ability to reach low to medium telescopic magnifications but still retain the advantage of binocular vision. You reach a point at higher mags where a telescope is superior to a BT due to its simpler optical design and higher resolution, though.

It comes down to different optics for different purposes. I personally use fixed mag. binoculars up to 22x for WF use, a 100mm BT for 33x-71x midpower views and telescopes up to 300x or so. One or another optic I have will frame an area of the sky or object the way I want to see it!

Rich


Post Extras: Print Post   Remind Me!   Notify Moderator  
OBERWERK
Vendor
*****

Reged: 06/24/03

Loc: OH
Re: "new" 70mm 45s new [Re: Mr. Bill]
      #5610542 - 01/07/13 04:34 PM

Quote:

Not to mention 45 degree oculars which are very desirable for those of us that spend most of our binocular time looking up....

Kevin...meant to ask, what is the prism clear aperture?

Am I going to vignette my 24 Pans with a 27mm fieldstop?

I think I remember 22mm being mentioned for the 90s.





Prisms are 24mm, but there is a 23mm stop at the base of the focuser.


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

Reged: 01/02/05

Loc: Lake Tahoe area, Nevada, USA
Re: "new" 70mm 45s new [Re: OBERWERK]
      #5610553 - 01/07/13 04:43 PM

Bill, you still get 20x @ 3.3° with your 19 Pans; 4°+ @ 16x with the 24s. I can't imagine the vignette with the 24s would be so bad as to be a deal breaker.

To add to any vignette, though, there might be quite a bit of field curvature with such a short focal length objective!

Rich


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

Reged: 02/09/05

Loc: Northeastern Cal
Re: "new" 70mm 45s new [Re: OBERWERK]
      #5610598 - 01/07/13 05:18 PM

Quote:

Quote:

Not to mention 45 degree oculars which are very desirable for those of us that spend most of our binocular time looking up....

Kevin...meant to ask, what is the prism clear aperture?

Am I going to vignette my 24 Pans with a 27mm fieldstop?

I think I remember 22mm being mentioned for the 90s.





Prisms are 24mm, but there is a 23mm stop at the base of the focuser.




Looks like 19 Pan with 21.3mm fieldstop would be ideal...



Post Extras: Print Post   Remind Me!   Notify Moderator  
OBERWERK
Vendor
*****

Reged: 06/24/03

Loc: OH
Re: "new" 70mm 45s new [Re: Mr. Bill]
      #5610603 - 01/07/13 05:27 PM

Quote:


Looks like 19 Pan with 21.3mm fieldstop would be ideal...





Yes, that would be 20x (375mm f/l).


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

Reged: 02/09/05

Loc: Northeastern Cal
Re: "new" 70mm 45s new [Re: Mr. Bill]
      #5610607 - 01/07/13 05:31 PM

Guess another issue is the robustness of the collimation...looks like you would have to pull the top of the "can" to make adjustments.



Post Extras: Print Post   Remind Me!   Notify Moderator  
OBERWERK
Vendor
*****

Reged: 06/24/03

Loc: OH
Re: "new" 70mm 45s new [Re: Mr. Bill]
      #5610634 - 01/07/13 05:54 PM

Quote:

Guess another issue is the robustness of the collimation...looks like you would have to pull the top of the "can" to make adjustments.





Yes, a pain to adjust, but it is a robust 3-point push-pull system. Once set, maintaining alignment will not be an issue with this model.


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


Reged: 10/21/09

Re: "new" 70mm 45s new [Re: OBERWERK]
      #5611886 - 01/08/13 12:42 PM

The studs on the sides of the tubes suggest that the instrument could be supplied with a proprietary fork mount (like Miyauchis were) - is this going to be the case?

Post Extras: Print Post   Remind Me!   Notify Moderator  
kray1
member


Reged: 06/22/10

Loc: NC
Re: "new" 70mm 45s new [Re: planetmalc]
      #5614410 - 01/09/13 07:58 PM

Thanks for the suggestions. The 100s certainly would give higher mags but I think that I will be happier with the 70s at 47X. That should offer a nice increase over the 25 x 100 and less light to tame the views of Jupiter and Saturn.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | (show all)


Extra information
8 registered and 33 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: 3499

Jump to

CN Forums Home


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics