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EdZ's 22 x 85 GO Signatures

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#1 Tom Reichel

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Posted 16 February 2009 - 10:53 AM

Any opportunity to try them out yet? :cool:

Tom

#2 EdZ

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Posted 16 February 2009 - 11:13 AM

not yet.
edz

#3 ngc6475

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Posted 16 February 2009 - 01:27 PM

I, too, have been waiting for word of Ed's experiences with this binocular. It seems to be an attractive binocular, according to its raw stats (except eye relief, unfortunately), and I am curious to know how well it performs outside.

I will just have to remain patient and wait for one of Ed's excellent reports! ;)

#4 EdZ

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Posted 16 February 2009 - 02:31 PM

Well, I'm waiting for delivery, which is iminent. But I can clue you all in on some of my expectations.

Taking specs on their value, which many here seem to do, the average consumer might expect an 85mm binoc to have only 12-13% greater light gathering power than an 80mm binoc. And it might also be expected that a 100mm binoc has 38% greater LG area than the 85mm. I do NOT expect that to be the case.

Having the Oberwerk Ultra 15x70 from this same product line, I know it delivers full aperture. I expect the 22x85 will also deliver full aperture, or at least very close. For my purposes now, I'll consider it full.

Having tested 3 fixed power 100mm binoculars, I know they provide aperture in the range of 90mm to 92mm. And I've measured magnification in the range of 22x to 23x.

And having tested 6 different 20x80 binoculars, I know they provide aperture only in the range of 70mm to 72mm. In fact, I've precisely measured one at 17x71, two at 18x72, and two at about 19x71.

From this I expect what others might not expect, and that is:

that the 22x85 will have approx 40% greater light gathering power than 20x80s, and will have 15%-20% greater magnification.
Also
that a 25x100 would have only about 15% greater LG power than the 22x85 and would give only about 5% greater magnification.

To be clear, I expect the 22x85 is a big step up from common 20x80s and is only a very small step below common 25x100s.

I'll let you know how my expectations prove out.

edz

#5 Mark9473

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Posted 16 February 2009 - 02:39 PM

I think many of the regulars on this forum have come to expect exactly what you just described, EdZ.
The 200$ question is then: what does the 22x85 have to make it preferable over a common 25x100, given that they don't have the advantage of smaller size or lighter weight.

#6 ngc6475

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Posted 16 February 2009 - 02:41 PM

That seems fair enough, Ed. My sole experience with a GO Signature binocular was positive, and I was impressed by its optical quality and construction. I would expect nothing less from the 22x85, which hits the sweet spot (for me) for magnification and physical size, but I would like an authoritative review to confirm or dash my preconceptions.

The one hitch in what appears to be a very serviceable binocular is usable eye relief, and that's what has prevented me from buying this binocular in the past. It will be interesting to read what you have to say on this subject.

Thanks for your response above, Ed!

#7 EdZ

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Posted 16 February 2009 - 03:04 PM

The 200$ question is then: what does the 22x85 have to make it preferable over a common 25x100, given that they don't have the advantage of smaller size or lighter weight.


Robust build quality I would think would be one consideration. Just the difference in prism shelf adjustment vs screws pushing on prism sides is one item.

For example, in 5 years, I've adjusted the prism screws in my GO 20x80 probably 10 times. In three years I've never needed to adjust the prism shelf in my 15x70 Ultra.


The one hitch in what appears to be a very serviceable binocular is usable eye relief,


that is a concern. We'll see how that develops. I use several others with short eye relief, including the Fujinon 16x70 and the Ultra 15x70 (11mm).


more

what does the 22x85 have to make it preferable over a common 25x100


IF, and that is a fairly BIG IF, the 22x85 shows similar measures and performance to its brethren, the 15x70 Ultra, then there are some other expectations.

My Obie 25x100IF Dlx and my GO 20x80 Gemini WP share the same family. The are cut from the long lineage, same as the Mariners and a half dozen other brands of binoculars that belong to this same family body. It's good, better than some others, but it's not perfect.

The 25x100 and 20x80 both show a fair amount of tilt in the light beam as it projects in the exit pupil. In other words, the center of maximum illumination is not at the center of the exit pupil. It is off to one side. The Ultra shows no tilt at all, it is perfectly centered and symetrically balanced. This is a trait seen repeated in other moderately priced or inexpensive binoculars versus higher end binoculars. I'd expect the 22x85 to follow suit with the Ultra.

In addition, both the 25x100 and 20x80 show almost identical percent illumination pattern in the exit pupil. For instance both the 25x100 and the 20x80 show that a beam entering the objective at a point anywhere within the central 25% to 30% out from center will illuminate the exit pupil 100%. The Oberwerk Ultra beats both handily by extending this range out to 45%. So here's hoping this GO22x85 shows the same beam characteristics as my Ultra.

These are indications that the Ultra/Signature family handles the light beam much better and provides greater total illumination, and therefore higher transmission. That's what I'm after. I'm hoping that's what I get.




edz

#8 Glassthrower

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Posted 16 February 2009 - 11:50 PM

I don't have EdZ' skills for critical analysis, but I did own a 25x100 binocular and the GO SS 22x85 binocular. I had the opportunity to observe with both of them over extended periods of time. I expected the 22x85 to show an increase in sharpness over the Celestron 25x100 (due to the higher quality and presumably better figure/polish), and I expected the image to be noticeably dimmer in the 22x85 due to the decreased aperture. What I experienced was surprising. Not only were the 22x85's noticeably sharper than the 25x100, but the image seemed equally bright to my eyes and brain. I know this is impossible, but I really didn't notice the lack of 15mm of aperture. (Well, the Celestron 25x100 is a not a true 25x100, as EdZ stated above, so the actual difference was probably less than 15mm)

I attribute this to the superior light transmission/coatings of the 22x85.

Another thing I noticed is that star colors seemed more vibrant than other binoculars I have used. This is something difficult to quantify and it will be interesting to see if EdZ notices this as well, or if it's just my goofy eyes.

As was mentioned above, the eye relief on the 22x85 was a bit tight for my tastes. But it's only an issue if you wear glasses while observing.

Regards and clear skies,

MikeG

#9 Mark9473

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Posted 17 February 2009 - 05:19 AM

Mike, did you take into account that brightness is determined by exit pupil?

#10 EdZ

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Posted 17 February 2009 - 06:26 AM

Brightness is determined by much more than exit pupil. As I explained above, testing for percent illumination across the exit pupil shows dramatically different readings in varying quality of binoculars. Brightness can only be compared by exit pupil IF both instruments have equal illumination. That is rarely the case.

I'll give you an example.
GO Gemini 20x80, aper = 71mm, exit pupil 3.8mm
fully illuminates the pupil 100% from every point within the central 35% of the objective diameter
produces 75% full exit pupil from every point within central 2/3rds of objective

Anttler Optic 20x80, aper = 71mm, exit pupil 4.2mm
Does NOT fully illuminate the pupil from any point within the central area of of objective
produces 75% full exit pupil from every point within only the central 50% of objective

Now, if you were to base your expectations of brightness on exit pupil, you would say the Antler must be brighter than the Gemini, since the Anttler has a larger exit pupil. But that is NOT the case. The Gemini is distinctly brighter. It has far better illumination. It can see fainter objects. It picks up galaxies easier. It can see about 0.3 magnitude fainter stars. The Gemini has greater total transmission and shows a brighter image, even though it has a slightly smaller exit pupil, because it concentrates more light from a larger area of the the objective into the central area of the exit pupil.

All else equal, you could make a comparison of exit pupil. But all else is seldom equal.

edz

#11 Mark9473

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Posted 17 February 2009 - 02:28 PM

I won't argue with that of course, but when Mike related brightness to aperture, the first-level correction was to point to exit pupil. You added the second- and third-level corrections.

#12 dOP

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Posted 18 February 2009 - 04:00 AM


Ed,

I read some threads linked on the "best of" thread regarding this matter and I didn't find any definitive reason on why these variations of illumination occur.

However it seems logical that the main reason is light not being transmitted by the prisms. In that case, the illumination would be determined by the prism size, material (glass) and the focal ratio of the objective. The worst case scenario would be an undersized BK7 prism on a short f/ objective - the light doesn't reach the periphery of the exit pupil.

Diogo.

#13 Glassthrower

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Posted 18 February 2009 - 11:03 AM


I won't argue with that of course, but when Mike related brightness to aperture, the first-level correction was to point to exit pupil. You added the second- and third-level corrections.


EdZ is just jealous that I have seen 5 moons of Jupiter and a Kuiper Belt Object in my binoculars. ;) :lol: :silly:

Regards and clear skies,

MikeG

#14 EdZ

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Posted 19 February 2009 - 07:30 PM

have finally arrived :cool:

Won't be doing any observing tonight.

When time allows I'll be noting anything I can about these, but for now thought I would just post the measures I got with the mask test.

In each case I took several measures, not just one.

exit pupil at
full aperture = 3.97mm would give 85/3.97 = 21.4x
69.7mm mask = 3.3mm 69.7/3.3 = 21.12x
61.7mm mask = 2.92mm 61.7/2.92 = 21.13x
50.5mm mask = 2.4mm 50.5/2.4 = 21.04

I took a bunch of measures with the masks. Got one hi at 21.25x, and one low at 20.94x. I got eight between 21.04x and 21.16x. That tells me power is 21.1x

I checked full aperture exit pupil a number of times. If it were 22x85, pupil should be 3.86mm. I set my caliper to 3.86mm and every time, had room to spare to see exit pupil right around the sides of the caliper. Several times I got measures of 3.97mm, so that's what I'm using.

At full aperture pupil of 3.97mm and actual power of 21.1x, the GO Signature 22x85 shows it is effectively 3.97 x 21.1 = 83.8mm.

I call it a 21x84.

I expected aperture to be very close to full. It is.

Compared to several of my 20x80s, which are:
17x71, 18x70, 18x72 and 19x71 and 19x72

and compared to two 25x100s, which are:
22.5x92 and 25x90

This GO22x85 is a bit smaller in physical size than the Oberwerk 25x100.
It rides pretty nice atop my 028B/501 head combo.

that's all for now.

edz

#15 ngc6475

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Posted 20 February 2009 - 12:25 AM

Thanks for the initial report, Ed. :waytogo:

#16 EdZ

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Posted 20 February 2009 - 05:57 AM

Walter, I had a chance this morning to observe a bit. Knocked off about a dozen galaxies. Notable was M51, seen as one large and one small.

Eye relief is tight.

Maximum fov is just a hair over 3.0°, 3.05, just slightly wider than the two eastern stars in the head of Draco. I could see both of those stars in both eyes at the same time, so my maximum fov was just a hair under 3°, 2.96. So, pressed up tight with my eyeglasses, I'm getting 96% of the fov. That's about the same for me as with the Fujinon 16x70.

3.05° x 21.1x = 64° Afov.

Nu Draco, a 1 arcmin equal pair, was still visible at the very edge. Total distortion was about 45-50 arcseconds at the edge. That's better than some 20x80s, but no better than the GO Gemini 20x80 or the Oberwerk Standard 20x80.

One little disappointment is this pair is out of collimation. Using Nu Draco (1 arcmin) I could easily determine these are 2 arcmin out of alignment, and the error is predominantly vertical error. I cycled them thru a range of IPD and found they would get as close as 1 arcmin out, but never merged. Minor issue, I can fix this. When I relaxed behind the lens, stars would easily split apart. Several times while viewing, images would separate. My eyes were forcing the merge. After a few minutes of viewing, when I looked away from the eyepieces, everything was out-of-whack for a few seconds.

From the Best Of
" Vertical Alignment, a serious error, is when one image is higher than the other image. The eyes have no muscles to accommodate for vertical error. The allowable divergence is only 4 arcmin at 7x to 10x, only 3 arcmin at 12x to 15x and 2 arcminutes at 15x to 20x. Personally, I cannot tollerate even 2 to 3 arcminutes of vertical error even at magnifications of 10x and only 1 arcmin at 16x."

At 21x, I need to adjust these to within about 30-45 arcseconds to be within my persoanl tollerance level.

I'll be away skiing for the weekend, so won't be busy with these until next week. But first task is, get them merged. Bill Fattz pictoral thread clearly shows where the screws are. His thread can be found thru the best of collimation.

#17 pcad

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Posted 20 February 2009 - 09:16 AM

Vertical misalignment, ouch! I know how that feel.
Vertical misalignment, ouch! I know how that feels.

#18 RichD

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Posted 20 February 2009 - 09:20 AM

Disappointing they arrived out of alignment, especially after the recent thread by the owner who dropped his 110's 5ft onto hard ground with no ill effects.

#19 eklf

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Posted 20 February 2009 - 10:18 AM

I, too, had a similar problem when I recieved my used GO SS 22x85s. Zach Garett was very kind to send me instructions for conditionally alligning these to my IPD (which, incidentally, I never used, prefering to get them collimated instead).

I am attaching those instructions here.

I am certain EdZ is well aware of these (pretty standard instructions except the location of the allignment screws), but perhaps these might be of some help to other owners of the series 8 binoculars.

Attached Files



#20 Wes James

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Posted 20 February 2009 - 10:18 AM

You know- it's odd... Garrett and Oberwerk have a good reputation, supposedly check every binocular for proper alignment before they go out- but I've had 3 Oberwerk's, 2 of which arrived out of alignment, and 3 Garretts- one of which arrived out of alignment. That's 50%, and not very good odds.

#21 RichD

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Posted 20 February 2009 - 10:24 AM

Seems the GO SS/Ultras are the three spring tilt plate arrangement. Great for adjusting yourself at home but not as sturdy as the eccentric ring type maybe.

#22 eklf

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Posted 20 February 2009 - 10:31 AM

Wes,

That is indeed disappointing, especially from these two respectable dealers who are the flagship of great quality control for otherwise "entry level" binoculars.

To be fair,though, EdZ's pair were bought used rather than directly through Garrett.

#23 Rich V.

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Posted 20 February 2009 - 10:35 AM

It's a shame that a new binocular has to be "conditionally aligned" for one IPD.

I suppose no big deal if the binocular is used by only one individual but if you like to share the view with others, it's not a great solution.

If it were anyone but EdZ I'd suggest sending them back to Garrett and the Mark V collimator and have things made right. If they hold collimation well it should be the end of the story!

Rich V

#24 EdZ

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Posted 20 February 2009 - 11:49 AM

They were bought used, not new, and I know most people out there wouldn't attempt this type of adjustment. There out, but almost within standards. I'll fix em.

I'm not making a big issue out of it at all. They are much more sturdy than the common push screw in contact with side of prism, which is what most binoculars are that are commonly referenced in this forum. How to (where to) has been published in this forum for since they first came out in 2006.

edz

Ironically, my Oberwerk Ultra 15x70 got knocked off the table (by my cat) and dropped 30" to the floor. After I just commented the other day how three years have gone by and I've never needed to touch these, that drop knocked them 5-6 arcminutes out of whack. They were unusable. I followed the pictures in the links (to find the screws) and tweaked them in about 20 minutes. They're fine now. I'm sure the 22x85 will be just as easy.

edz

#25 pcad

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Posted 20 February 2009 - 12:06 PM

Must be a pretty big cat. Those Ultra 15x70's aren't exactly light weight bino's. ;)






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