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Canon 10x42 IS L Tripod vs hand-held vs IS testing (1 Viewer)

Phil,

This head movement issue is familiar to me also, but I have done so much of tripod-mounted binocular testing over the years that I am rather used to it have learned to keep my head rather still. My guess is that firstly it is harder to keep two eyes aligned with exit pupils than one, and also that this is harder to do with the straight-through view of binoculars than with the 45 deg angled view of the scopes I use.

It goes against conventional wisdom that you would get significantly better hand-held results with a 10x than with an 8x binocular, but that is also the result I have had the few times I've done hand-held detection or resolution tests with different magnifications.

Some of those I reported in my old review of the Canon 15x50 IS. If you are interested, and haven't happened upon it yet, here's the link to the index page of my Lintuvaruste reviews, which were originally published in Alula and Linnut magazines: http://www.suomenlintuvaruste.com/product_catalog.php?c=88

There is also a review of the 10x42 IS L, which pertains to the first year or two models, prior to the improvements to MC coatings, internal baffling and IS functioning. I'm thinking of updating that review with the experiences from this newer model, but it may be a while before I get around to actually doing it

It has been surprising that the Canons have not achieved greater popularity. But as long as the few of us who use them and like them get to continue doing that, I've decided not to care that there is little following.

I have been planning on doing a reading distance test IS vs hand-held also. Please post your results when you get the 8x vs 10x comparison done.

I owned a Nikon ED 82 A for many years. A very fine scope you have.

Kimmo
 
Henry,

Just to be sure, I measured the true aperture of the Leica 8x20 Ultravid with the card obstruction method, but it turned out to be just the 20mm it is supposed to be. The thought had occurred to me that if it happened to be, say, 22mm that would help explain the boosted resolution somewhat.

These 112.5/D etc. results were obtained with a booster, so this is not about exceptional VA. The exit pupil here was 0.83mm. Thus far, I have never obtained VA readings under 60" like David has. It may be possible on a good day, but very likely not by much.

Kimmo
 
I get improved resolution the more magnification I use with handheld binoculars.
For instance I see finer detail with a 10 times compared with an eight times binocular.
Finer still detail with a 15 times compared with a 12 times.
And even finer detail with a Soviet selected 20×60.

These improvements are usually confined to observations perhaps lasting one second or less.

The weight, bulk and inertia of the larger binoculars play a part.
Also, there is improved resolution at the bottom or the top of any hand movements, which may follow something like a sine curve.

On the other hand, I have frequently found it easier to see Jupiter's moons with an eight times binocular than a 10 times binocular with the same aperture and type.
So one cannot always predict the results.

When observing filtered unaided eyes sunspots with no magnification at all, I get 5% to 10% improvement by resting my head against a lamppost in the street compared with the observations with my head completely unsupported.

It obviously is a personal matter as to how steady an individual is, so I have no idea if my measurements are typical.
 
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Finally I fixed up a page of plain text and found the maximum distance at which I could read it out loud at normal reading speed without making mistakes - 10.5 metres using the 10s then tried the 8s from the same distance - I couldn't read it at all - maybe guess at the odd word. I should have then moved forward to find the "comfortable" reading distance for the 8s so that I could give a percentage figure to the difference but I forgot to do it. It's an easy set-up though so may have another go tomorrow and also check out the amount of head movement I get with the scope (though I've never noticed any). So fairly conclusive for us with these particular bins the 10s come out on top in terms of resolving detail. I want to repeat this test now with one of my friends Swaro 8x32SV against my 10s.

Hi Torchepot,

You'll be happy to know you've just reinvented Steve Ingrahams NEED test, http://betterviewdesired.com/NEEDtest.php
which he used to help evaluate binoculars in his Better View Desired blog.
Steve, now at Zeiss, pioneered the optics oriented blog and although the most recent BVD reviews are almost a decade old, the blog is still well worth reading.

Separately, the point you raise about head movement impacting the seeing through a fixed glass seems obvious, except that afaik it is nowhere discussed in the literature. We learn new things every day....
The effect should help IS binoculars apparent hand held VA, as presumably the head movements become inputs to the glass stabilization sensor. Maybe that is why the gap between stabilized and fixed site VA is so small in the tests.
 
Hi Kimmo and Binastro,
Thanks for both your responses. I didn't make it clear what I was trying to achieve but you got it straightaway anyway(of course!). Lots of birders - including several of my friends have been telling me that they see more detail with 8x optics than with 10x based on the fact that they are easier to hold steady or at least that any shake is less magnified. I'm seeing a lot more people using 8x32 Swaro SV lately. I've tried a few pairs and really like them but somehow haven't been really convinced of their argument. You would think it would be really easy to detect significant differences in resolution but I think other factors can get in the way - particularly brightness and FOV.
Just a few minutes today showed me that to get a more accurate idea of the resolution differences between optics or even to gauge the difference between binoculars on and off the tripod I personally at least need some way to measure it. Just looking at a leaf or a tv antennae I could only get a "feeling" about which showed more detail, considering the likely difference I'm really quite surprised that it wasn't more obvious.
I think the next step for me will be to get some kind of chart (thinking of using the one that "atomic chicken" posted ages ago) so that I can quantify the differences.
It would be interesting to have a blind test to find out how good observers really are at detecting differences in resolution without the aid of charts etc.
Thanks again for your input - you've really got me thinking!

Cheers, Phil
 
Separately, the point you raise about head movement impacting the seeing through a fixed glass seems obvious, except that afaik it is nowhere discussed in the literature. We learn new things every day....
The effect should help IS binoculars apparent hand held VA, as presumably the head movements become inputs to the glass stabilization sensor. Maybe that is why the gap between stabilized and fixed site VA is so small in the tests.

That's very interesting stuff. I've noticed before that I get more detail on a bird when using my 20x60S Mono on a tripod with the stabilizer engaged. The difference is pretty clear-cut IMO. The 20x60S is a straight-through monocular, and maybe the head movements are larger (and hence the vibrations transferred via the eyecup to the 20x60S) than when using the 45 deg angled view of my Nikon scopes.

Hermann
 
Hi Etudiant,
Thanks for your reply, I know BVD but not the NEED test - like you say there's always something new to learn. Lots to think about!

All the best,

Phil
 
Hi Hermann,

That's intriguing, maybe the act of looking down stops some of the head movement? The Nikon allows me to rotate the back part of the scope I think - so that I can directly compare the two viewing positions within a few seconds of each other. For the horizontal view I'll have to raise the tripod and stand off to the side a bit but should be able to make a comparison. I'll let you know what happens.

Cheers,

Phil
 
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That's intriguing, maybe the act of looking down stops some of the head movement? The Nikon allows me to rotate the back part of the scope I think - so that I can directly compare the two viewing positions within a few seconds of each other. For the horizontal view I'll have to raise the tripod and stand off to the side a bit but should be able to make a comparison. I'll let you know what happens.

I think so. I used straight-through scopes for several years, and when I switched to angled scopes I felt the viewing was much more relaxing. That's to some extent probably due to the fact that with a straight scope the height has to be adjusted *very* carefully so it's just right, whereas angled scopes are much more forgiving. And as soon as you change the angle of viewing with a straight scope you have to adjust the height again to make sure it's right ...

Straight scopes are a no-go for me nowadays. The great thing about the 20x60S is that you can use it without any tripod for a quick look. For longer periods the viewing gets too tiring, it's not that light ...

Hermann
 
The great thing about the 20x60S is that you can use it without any tripod for a quick look. For longer periods the viewing gets too tiring, it's not that light ...

Hermann

Does the 20x60S have a tripod fitting for a Finnstick?
Kimmo has indicated that that really helps ease the weight issue.
 
A rainy day in Spain - that's not supposed to happen! still only the first this year, but no birding or chance to continue tests outdoors. I did just get the chance to check on this odd head movement I reported when using the bins on a tripod. I tried viewing through my scope horizontally (it's an angled scope) by turning it on its side - and even though the magnification is much greater - 38x fixed - compared to 10x - head movement is virtually undetectable with the scope and yet quite pronounced with the bins. Next time I have the bins on the tripod I'll try closing one eye and see what difference that makes.
 
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Henry,

Just to be sure, I measured the true aperture of the Leica 8x20 Ultravid with the card obstruction method, but it turned out to be just the 20mm it is supposed to be. The thought had occurred to me that if it happened to be, say, 22mm that would help explain the boosted resolution somewhat.

These 112.5/D etc. results were obtained with a booster, so this is not about exceptional VA. The exit pupil here was 0.83mm. Thus far, I have never obtained VA readings under 60" like David has. It may be possible on a good day, but very likely not by much.

Kimmo

Kimmo and David,

I made a major effort last night and this morning to see if I could mange to detect line orientation on the USAF glass slide at better than 115/D. I concocted a "perfect" optic by stopping down my A-P Stowaway to 24mm, 22mm and 19mm in my usual indoor 10m set-up. I used various eyepieces and magnifications between 25x and 125x.

To make a long story short I found that I could reliably detect whether bars were horizontal or vertical down to almost 110/D. It was all the more convincing because I had incorrectly recalled which set of bars were vertical and which were horizontal in the 2,1 and 2,2 elements, so my expectations were contradicted by what I saw, always a good sign of a reliable observation.

Henry
 
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Henry,

Thanks for this. It maybe does not quite save the credibility of my observations yet, but would seem to go some ways towards that. Could you get that with the 22mm also, or just with the 24mm?

I took the Leica 8x20 to the store today and looked at some glitter points through it. They were as I recalled. A clean round point with a clean single ring around. Some SA in out-of-focus ring patterns, but much less than typical in binoculars.

Kimmo
 
Kimmo, the 110/D was with the 24mm and 19mm stopdowns. I could only do about 113/D with the 22mm, which must have been related to the resolving power falling between elements. I'm sure there is enough slop in my measurements of distance and aperture using household tape measures and rulers, not to mention my old man eyesight to make any of my measurements so close to the noise floor no better than +/- 5%.

I don't think a binocular that has you guessing at this level of resolution is one you have to worry about. That's why I suggested that your dissatisfaction with the Ultravid might be related to the exit pupil being smaller than your best diffraction limited pupil size.

Henry
 
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Henry,

I'm not worrying about the Ultravid as a binocular, I've seen enough binoculars to know that it is as sharp as any 20mm binocular is ever going to be. My concern really has only been about finding an explanation for the resolution figure relative to aperture that is better than in any other optics I have yet tested, but I'm now coming to terms with thinking that it is real and not a silly error that eludes me.

Your suggestions about my best d.f.l. pupil size being larger than 2.5 is quite possibly correct. If that is so, however, it casts a new and interesting light on our earlier discussion on how close to diffraction limited do binoculars need to be in order to be perceived as sharp as can be.

As far as the precision of measuring distances accurately enough with household tape measures and rulers. +- 5% at 10 meters is a whopping 1 meter, and it is very easy to get to one tenth of that as a margin of error. Calipers work pretty well for establishing aperture diameters to better than the closest millimeter, so I don't think our margin of error is actually that large. The biggest source of error is the steps in the resolution target, but by adjusting the distance and finding the limiting resolution distance, then calculating from there, avoids this error quite handily.

Kimmo
 
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Henry and Kimmo,

You both are getting results about 1 pattern better than the best results I've obtained at 20mm stopped down. I don't know if that's due to differences in optical quality or the way we score the charts.

I wouldn't have thought many would judge me a pessimistic reader of charts. My best estimates for two eyed acuity are 54". I've had 4 binoculars that have given me 128/D which I'd rate as excellent yet they result in apparent acuities a few seconds worse my unaided result on the day. The only binocular that has allowed me to match my 54" value gave me a 124/D result. It seems to me this is an exceptional binocular. Is it really an arcsecond worse than your two results? A bit of a puzzle!

David
 
Hi Kimmo,
Just wanted to say thanks for the link to your reviews, one word immediately springs to mind RESPECT!!
I had read your ATX review previously but the Canon reviews were new to me - I'm not surprised that it may take you a while updating one of your reviews - they are exhaustive! (And very probably exhausting!?)
Your thorough examination of all aspects of the 10x42IS has put my mind to rest over any doubts about the optical performance. I just need to get my hands on one now to make sure it's right for me.

Talking of the ATX I've been very happy with my ED82A until I made the terrible mistake of looking through an ATX95 - I'm not usually prone to optics envy but I know what it feels like now!

Thanks again

Phil
 
Phil,

Thanks for your kind words concerning my reviews. I know they are not everybody's cup of tea, but back when I started I felt that there were no well-conducted reviews available, and so the solution was to do them oneself. There had been one fellow doing really good reviews in the eighties and the nineties here in Finland, but he stopped doing them.

With the 10x42 Canon, keep the sample variation issue well in mind. I haven't seen enough of the recent samples to know if average production tolerances have improved, but even if they have, there can always be samples where telescope collimation in one or both tubes is off by enough to be objectionable. With stabilization, you will be able to see defects much more easily than in normal handheld binocular views.

The ATX 95 was the first new scope after the introduction of the ED82A that was better by enough of a margin that it made me upgrade. Up to that point, the Nikon had always at least held its own.

David,

I think your 124/D and 128/D are actually exceptionally good results for a binocular, even considering that they were stopped down to 20mm results. Almost all of the binoculars I have tested have had enough optical defects other than simple SA to make such a result hard to get. Most common is coma from less than perfect centering of optical elements around a single optical axis, and another very common one is prism roof defects that are not bad enough to make the binocular fail the DIN standard but readily show as astigmatism in best focus glitter points.

Henry's AP Stowaway he did his tests with is a true apochromat, with almost no SA even unstopped, and stopped down to 20mm is likely to be so close to perfect that whatever may remain from perfection makes no discernible difference. He also does not use a diagonal that would have any prism edge defects to introduce.

The Leica Ultravid, though, is none of the things Henry's scope is. However, (and I have said this more than once on threads on small binoculars in the past) it is the most defect-free binocular I have ever tested, and both resolution target images and best-focus star patterns look textbook near-perfect. Nevertheless, since the Leica has roof prisms and is operating at its full aperture, its results are astonishing. I'm assuming that my eyes are simply a bit better than Henry's at detecting line orientation at very low contrast through an exit pupil only 0.8mm or thereabouts. I must also mention that I can achieve these booster results only with my previously non-dominant right eye, since my formerly dominant left eye has very slight cataracts. This cataract business I first noticed about a year ago, when testing my ATX telescope and noticing that while at 2mm + exit pupils I had no problems, at 1,5mm and under I could no longer detect patterns I had been able to in the past, and switching to my right eye magically restored the pattern. Another possible difference is in the light source for the glass slide target, but I don't know enough details about Henry's setup to know.

When you do your two-eyed acuity tests, do you use your (possible) eyeglasses or not? As I said, I can no longer focus on a test chart with my eyes only, but when I test binoculars I never wear glasses so it is only my eyes and the bin or scope. I do not think I could go much under 60".

Kimmo
 
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Kimmo, FWIW I don’t doubt your resolution results of the 8x20. My best pair of 8x20 UV’s is good, not as good as yours, but I regularly get 6,3 at 400 mm in both tubes and occasionally get very close to resolving 6,4 in the left tube so I am pretty sure I am getting about 120/D or 6” and, occasionally, close to 114/115/D. MTF and star testing indicates this instrument is just shy of 1/2 wave, not nearly as good as your sample.

For the past few years I have had some questions about diffraction limits anyway, based on some discussions and reading some points by the Hubble team. They had to put glasses on Hubble and I have not read anything about a known grinding error.

Just as a food for thought, focus and refraction are a matter of established physics but resolution, as near as I can find out, is based strictly on empirical data by Dawes and Raliegh, with the math fitted to that data. Their observations were through a liquid medium (atmosphere) with a variable density, temperature and dust content, so the results represent an average refraction of atmosphere, assumed as one.

There have been two scenarios that seem to point to errors in diffraction theory (a lot of knowledgeable people don’t use the term “diffraction limited” anymore), one is the space telescopes with no atmosphere, the other is based on spy drone technology where 360 cell phone cameras are mosaiced together for city wide high resolution images, I have heard figures like “better than a quarter meter from 17,000 feet, not bad for a bunch of 2 mm cell phone lenses. Another is the multiple telescopes feeding a common sensor; this seems to act like phased radio antennas.

I have not really done much research on this since it really does not effect the way I measure resolution to just compare one optic to another, all that matters is if one will resolve better than another.
 
For the past few years I have had some questions about diffraction limits anyway, based on some discussions and reading some points by the Hubble team. They had to put glasses on Hubble and I have not read anything about a known grinding error.

The Hubble glasses were to correct a grinding error.
Allegedly a probe used to check the depth of the grind had a 1 mm defect, so the mirror was misground accordingly. Because the error was so exact, a suitable correction was possible. More detail here:
http://www.nytimes.com/1993/12/07/science/some-feared-mirror-flaws-even-before-hubble-orbit.html
 
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