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Can a small bino really deliver? (1 Viewer)
- Thread starter Super Dave
- Start date
elkcub
Silicon Valley, California
The 10x and 8x produce the same apparent field, which I compute as 54 deg. (I don't use Nikon's method, which computes to 50 deg.)
http://shop.nikonusa.com/DRHM/store
The Bushnell produces a smaller apparent field of 48.5 deg. (with my method).
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=380297100375&item=380297100375
A price difference of $200 or so is quite reasonable for what you'd get. Of course, if you already own the Elite 7x26 I'd just tuck them under my jacket.
Ed
Super Dave
Well-known member
After trying the new Bushnell Elite 7x26 and the old Bushnell Custom 6x25 I decided to keep the older one. The Elite is a little brighter but I couldn't tell much of a difference in the image quality (other than the 7x being a little more powerful). I also had less eye placement issues with the 6x25.
The 6x25's are a lot smaller as these photos show.
Although the case on the 7x26 is really cool I thought it was bigger than it needed to be. The case definately makes it way too big to fit in any baggy pockets I have.
The build quality on both is excellent. I'm really surprised how smooth the old one has remained after all these years. The focus wheel is tied into the objective lens side of the binocular. When I stand the 6x25's up on their objective lenses the focus wheel will spin just from the light weight of the bino. That some good machine work. Whatever grease they used is still working great.
Can someone fill me in about the production years of the 6x25's? I thought they were only produced in the beginning of the Custom Compact line.
I also have one question on the Nikon 10x25 LXLs. I've read that the resolution of all compacts drops over longer distances due to their small objective size. How do you find the resolution of the 10x25 LXL's when looking out over long distances...like on the ocean, etc?
Aloha,
Dave
The 6x25's are a lot smaller as these photos show.
Although the case on the 7x26 is really cool I thought it was bigger than it needed to be. The case definately makes it way too big to fit in any baggy pockets I have.
The build quality on both is excellent. I'm really surprised how smooth the old one has remained after all these years. The focus wheel is tied into the objective lens side of the binocular. When I stand the 6x25's up on their objective lenses the focus wheel will spin just from the light weight of the bino. That some good machine work. Whatever grease they used is still working great.
Can someone fill me in about the production years of the 6x25's? I thought they were only produced in the beginning of the Custom Compact line.
I also have one question on the Nikon 10x25 LXLs. I've read that the resolution of all compacts drops over longer distances due to their small objective size. How do you find the resolution of the 10x25 LXL's when looking out over long distances...like on the ocean, etc?
Aloha,
Dave
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tpcollins
Well-known member
I thought the original thread was "can small binos deliver" and somehow 32mm and 42mm objectives became involved. I have 20mm, 26mm, 32mm, 42mm binocs and they each have their place. I don't try to compare them against each other, and my Leica 8x20 Trinovid does exactly what I want it to do.
Another limitation of compacts is their lack of resolution at anything beyond about 100 feet because of their small aperture. Fine for close range birding but good luck at any distant birds. I really noticed that with my compacts. Beyond 100 feet you don't get near the detail of the full size binoculars. Here is a good article from Better View Desired describing the limitations of compacts.
http://www.betterviewdesired.com/compact-binoculars-bvd.php
vop
Well-known member
Wow, can you tell me how to get a 4 mm exit pupil from a 10X25 bino?
And also, good luck really is the best traveling companion!
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Tvc15_2000
Well-known member
Perhaps the sub title of this thread could also be:
“What is the best binocular that can fit in a 1.5 inch X 2.5 inch X 5 inch case (about the size of a black board eraser) that provides a WOW experience”.
I respectfully disagree with the description, poor resolution beyond 100ft, “toys”, “really bad”, or “better than nothing” etc. But I don’t question that is how it appears to your pair of eyes. I find the top small bins remarkable tools for the size.
If I was given a choice of only one binocular I would probably take a 10X32, but if I could choose two binoculars a 10x25 Ultravid, Zeiss, or Nikon LXL would be my backup choice simply because they provide an outstanding image for the size and provide opportunities for constant birding that would be missed when the larger bins are at home collecting dust.
I am of course envious of those who have the luxury of lugging around a 32 or larger at all times.
Good Birding.
“What is the best binocular that can fit in a 1.5 inch X 2.5 inch X 5 inch case (about the size of a black board eraser) that provides a WOW experience”.
I respectfully disagree with the description, poor resolution beyond 100ft, “toys”, “really bad”, or “better than nothing” etc. But I don’t question that is how it appears to your pair of eyes. I find the top small bins remarkable tools for the size.
If I was given a choice of only one binocular I would probably take a 10X32, but if I could choose two binoculars a 10x25 Ultravid, Zeiss, or Nikon LXL would be my backup choice simply because they provide an outstanding image for the size and provide opportunities for constant birding that would be missed when the larger bins are at home collecting dust.
I am of course envious of those who have the luxury of lugging around a 32 or larger at all times.
Good Birding.
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Super Dave
Well-known member
Yea, I didn't know what I was talking about in the beginning of the thread. That's why I asked the question about why my compacts were not delivering the same great views as the full sized ones. Now I know you can't have everything.
Aloha,
Dave
Aloha,
Dave
Kevin Purcell
Well-known member
I don't know where these odd statements come from.
The resolution of a bin is the same at all distances and exceed that of the resolution of the naked eye. Even with 20mm objectives.
The Dawes diffraction limit in arc seconds 116/D (D is objective diameter in mm). So the limit for a 20mm objective is 5.8 arc seconds or with 8xmagnification about half the resolution of the eye.
Or the other way of looking at it is at 2.5mm entrance pupil the diffraction limit for the compact bins and the naked human eye is about the same at 46 arcseconds or about half the actual resolution of the eye .
Funny how natural selection does that to the eye. And funny how the designers stop at 20mm for 8x bins
This is just a simple example and smaller bins probably do have worse MTF curves (i.e. they'll loose contrast a little faster at higher spatial frequencies) but I'm not at all sure you can see that as it's heading below the eyes resolution at that point.
BTW, BVD does get stuff wrong too e.g.
No, they don't.
If your eye's are stopped down to 2.5mm then it doesn't matter (for brightness) what the objective size is. It might for stray light but larger objectives won't see further into the shadows.
Smaller bins have problems with glare and reduced contrast (which might prevent them "seeing in the shadows") but that's not quite the same explanation.
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I have tested lots of the very compact models in the past, and I fully agree with Sancho. The small Ultravids are the most compact ones that should fit your bill when you are searching for that certain "rush" to your brain.
james holdsworth
Consulting Biologist
I don't know where these odd statements come from.
The resolution of a bin is the same at all distances and exceed that of the resolution of the naked eye. Even with 20mm objectives.
The Dawes diffraction limit in arc seconds 116/D (D is objective diameter in mm). So the limit for a 20mm objective is 5.8 arc seconds or with 8xmagnification about half the resolution of the eye.
Or the other way of looking at it is at 2.5mm entrance pupil the diffraction limit for the compact bins and the naked human eye is about the same at 46 arcseconds or about half the actual resolution of the eye .
Funny how natural selection does that to the eye. And funny how the designers stop at 20mm for 8x bins
This is just a simple example and smaller bins probably do have worse MTF curves (i.e. they'll loose contrast a little faster at higher spatial frequencies) but I'm not at all sure you can see that as it's heading below the eyes resolution at that point.
BTW, BVD does get stuff wrong too e.g.
No, they don't.
If your eye's are stopped down to 2.5mm then it doesn't matter (for brightness) what the objective size is. It might for stray light but larger objectives won't see further into the shadows.
Smaller bins have problems with glare and reduced contrast (which might prevent them "seeing in the shadows") but that's not quite the same explanation.
Kevin,
I have never really understood the whole resolution response, essentially that most any binocular will easily outresolve the human eye and that res. testing needed to be greatly boosted to see a difference.
So, if I take three binoculars, all 10 x 42, in good light, and read small print [something like a medicine bottle] some models will be able to read the smallest print and others cannot.
Is this not resolution and doesn't the binocular that can read the finest print have the best resolution? Didn't Ingraham do basically this with his NEED test?
All I know is that my 10 FL clearly shows more fine detail, both close and far, compared to my two other 10's. This is especially noticable when looking at very distant tree branches or other fine objects. To me, the FL has clearly better resolution. So, what am I seeing? Is it better contrast, not resolution?
Thanks for any further info.
optiman
Well-known member
Hi Ed,
Thanks for the advice and the stats on the HG L's or (LX L's) as you'd say. Interesting that they have the same 'apparent' FOV. :t:
James I agree with you. I can not see detail as well with compact binoculars at a distance especially as with full size binoculars. In daylight I have compared them many times and some binoculars as you say clearly show fine detail better than others. I also refer to the NEED test and other resolution tests that various reviews have referred to when ranking binoculars by resolution. Kevin is basically saying all binoculars outresolve the human eye so there is no perceptible difference in them due to resolution . I say that is baloney! Most reviewers call it resolution but he is saying the difference we see must be contrast or brightness or some other factor. So when you say your Zeiss FL is sharper or resolves more detail that is not better resolution. I think we are missing something here. A larger aperture binocular will outresolve a smaller binocular on the night sky when trying to discern small detail in a nebula or whe seperating double stars but when looking at a distance object in the daytime Kevin is saying a 20mm compact will show detail as well as 50mm aperture. I don't buy that.
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This is an enjoyable discussion. It is superstition to believe in things we can't understand, they say. It is another kind of superstition to disbelieve observations, because they don't "make sense".
Thanks Kevin, for the reminder of theory. And thanks Dennis, for telling us what you see. I think both of you are "right" but something clearly does not jive here. Perhaps we just don't have the theory yet to explain Dennis!
Really, I expect it's partly the failure of binoculars as usually constructed to actually realize the perfection of the theory. Also, a pet idea of mine, there is a certain sharp look to a binocular that outresolves the eye a good solid 3 times or so. Barely resolving better than the eye is not nearly good enough for "people like us", because separating closely spaced lines is not the whole game. Just some idle thoughts. I would like to try a top notch compact, but have not had the pleasure.
Ron
Thanks Kevin, for the reminder of theory. And thanks Dennis, for telling us what you see. I think both of you are "right" but something clearly does not jive here. Perhaps we just don't have the theory yet to explain Dennis!
Really, I expect it's partly the failure of binoculars as usually constructed to actually realize the perfection of the theory. Also, a pet idea of mine, there is a certain sharp look to a binocular that outresolves the eye a good solid 3 times or so. Barely resolving better than the eye is not nearly good enough for "people like us", because separating closely spaced lines is not the whole game. Just some idle thoughts. I would like to try a top notch compact, but have not had the pleasure.
Ron
henry link
Well-known member
Sometimes closer scrutiny and better controlled test conditions change what we "see". And I won't even mention jumping to conclusions about causes and effects.
Ron,
I agree with the "sharp look" idea, which I associate more with low aberrations than ultimate resolution. I think that look is often confused with a true increase in visible resolution. After all, even a dinky 20mm aperture at 8x should be about twice as good as eyesight acuity. In bright daylight we're typically using only the center 16-24mm of the aperture of any 8x binocular anyway, so the resolving power of large aperture binoculars under those conditions is no better relative to eyesight acuity than small ones.
Off topic, I noticed that you acquired a 8x30 FMTR-SX. I agree that the eyecups are too long. Also, check out the total absence of pincushion distortion. It's a good test of your tolerance for rolling ball.
Henry
Ron,
I agree with the "sharp look" idea, which I associate more with low aberrations than ultimate resolution. I think that look is often confused with a true increase in visible resolution. After all, even a dinky 20mm aperture at 8x should be about twice as good as eyesight acuity. In bright daylight we're typically using only the center 16-24mm of the aperture of any 8x binocular anyway, so the resolving power of large aperture binoculars under those conditions is no better relative to eyesight acuity than small ones.
Off topic, I noticed that you acquired a 8x30 FMTR-SX. I agree that the eyecups are too long. Also, check out the total absence of pincushion distortion. It's a good test of your tolerance for rolling ball.
Henry
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Henry,
Right. So let's see, your personal choice is a __mm?
Off topic reply regarding 8x30 Fujinon:
Thanks for your comment. This binocular has been discussed in some detail here on BF, and I agree with your findings, is why I chose to do my new-toy rantings over on CN. I sure wish you could get back on over there.
To me it looks like it has a just perceptible bit of pincushion (in rooting around BF to learn what I could about the 8x30, I discovered that even you have equivocated on this matter in the past, and I think it's because it's just such a tiny distortion that the manner of observation may influence the outcome), and is loaded with rolling ball, which is noticeable if I try to notice but doesn't bother me at all in normal use. Stargazing, I am a bit more edge conscious than in the daytime, and there I notice the magnification distortion near the edge, as star patterns get squeezed radially.
Shaving off 2mm of eyecup and resmoothing the edge did the trick for me. I like this better than the brow-propping method. The eyecups do a nice job of quickly centering and setting the back position of the eyes, block light from the side, and are more comfortable than the single-point contact against thin-skinned bone.
Ron
Right. So let's see, your personal choice is a __mm?
Off topic reply regarding 8x30 Fujinon:
Thanks for your comment. This binocular has been discussed in some detail here on BF, and I agree with your findings, is why I chose to do my new-toy rantings over on CN. I sure wish you could get back on over there.
To me it looks like it has a just perceptible bit of pincushion (in rooting around BF to learn what I could about the 8x30, I discovered that even you have equivocated on this matter in the past, and I think it's because it's just such a tiny distortion that the manner of observation may influence the outcome), and is loaded with rolling ball, which is noticeable if I try to notice but doesn't bother me at all in normal use. Stargazing, I am a bit more edge conscious than in the daytime, and there I notice the magnification distortion near the edge, as star patterns get squeezed radially.
Shaving off 2mm of eyecup and resmoothing the edge did the trick for me. I like this better than the brow-propping method. The eyecups do a nice job of quickly centering and setting the back position of the eyes, block light from the side, and are more comfortable than the single-point contact against thin-skinned bone.
Ron
james holdsworth
Consulting Biologist
I guess that I am no closer to understanding resolution or how it applies to binoculars.
Both Dunne and Ingraham often mentioned superior resolution in certain bins, and the qualifier was that these bins could see more and finer detail. I know that if I take my B & L 10 Custom and compare to my B & L 10 Elite and look at small, fine items [like the pattern of a lace curtain] I can clearly see more [and finer] detail with the porro [the Custom].
The porro will give me sharp, well-defined edges, while the roof will be slightly softer, without the definite edge to the patterns. This is also evident on more distant objects, like distant tree branches.
I know that almost every cheap bin I have ever tried just doesn't give those truely sharp edges on distant objects and that is what I have always thought of as resolution.
Both Dunne and Ingraham often mentioned superior resolution in certain bins, and the qualifier was that these bins could see more and finer detail. I know that if I take my B & L 10 Custom and compare to my B & L 10 Elite and look at small, fine items [like the pattern of a lace curtain] I can clearly see more [and finer] detail with the porro [the Custom].
The porro will give me sharp, well-defined edges, while the roof will be slightly softer, without the definite edge to the patterns. This is also evident on more distant objects, like distant tree branches.
I know that almost every cheap bin I have ever tried just doesn't give those truely sharp edges on distant objects and that is what I have always thought of as resolution.
Me too. I guess it is something else if all binoculars have the same resolution as seen by the human eye. Hmm. That's means I can go get a 15mm Tasco and it going to be as sharp as 56mm Zeiss FL. I'm selling my Zeiss FL and my Nikon EII's today if all binoculars have the same resolution.
