Canon 8x25 IS brief test (1 Viewer)

. This test of the 8×25 image stabilised binocular on a bright sunny day.
Weight 498 g with battery.
Field 6.50° or 6.55° approximately, no chance to test it on the stars.

Almost no chromatic aberration centrally, some chromatic aberration at the edges.

A small amount of pincushion distortion at the edges.

Possibly made in April 2014. Made in Japan

Compared with a full-size top-quality 10×42 binocular the image in the 8×25 is much less bright.
However, the white pillars are white.

The resolution of the small pimple on the chimney pot 400 feet away is 50% to 70% better than without the image stabiliser. In fact it cannot be seen without the stabiliser.
But I'm judging it against many other binoculars.
The resolution of the 8×25 with the stabiliser on is equivalent to a good standard 13 times binocular. This is for a static target.

Looking at an aircraft about 2 1/2 miles away it was easy to read the carrier's name on the side of the aircraft with the stabiliser on but impossible to read it with the stabiliser off.
On a moving target such as this the resolution is 100% better with the stabiliser on.
And an aircraft 10 miles distant easily showed the winglets with the stabiliser on but these were not seen with the stabiliser off.

A carrion crow happened to be sitting 1.5 feet to the right of the pimple on the chimney pot.
Much more detail was seen with the stabiliser on, perhaps 100% better.
However, there was a hint of false colour at the edge of the crows outline.

With the stabiliser on, the oscillations have about the same frequency as with the stabiliser off, but the amplitude is about 1/8 as much.
This looks rather strange if you carefully examine the detail, as there is an obvious fairly rapid but very small oscillation.
This seems to be quite different to the stabilisation of the larger Canon binoculars such as the 18×50 and others of 10×,12 times and 15 times.

The 8×25 has a tilt mechanism apparently of the third element of the objective from the front, whereas I think that the others have variable prisms.
There is also an optical window in front of the 8×25 and I think in front of many, perhaps all of the other Canon image stabilised binoculars.

If you look into the front of the binocular you can see an element moving as you press the stabiliser button. The stabiliser only operates when you press the button.

There are two perhaps three uncoated surfaces at the front of the binocular, but the eyepiece, which is quite complex has nice multi-coatings.
I would guess that the transmission is about 75% to 80%.
I don't know how the focusing is done, or whether the tilting element is also the focusing element, but probably not?

This is a great little binocular for some, but it is not waterproof.
It will be mainly used for watching cricket matches.
It does not seem to be as robust as a top quality binocular, but it costs less than half as much.
The guarantee is only one year.
For elderly people or people who have unsteady hands this should definitely be a binocular to be considered.

I have tested an earlier 8×25 image stabilised binocular but I'm not sure if it had a different stabiliser system.

Very interesting observations on a binocular I never really looked at myself. Looks like I should ...

Hermann

Thanks for the very interesting write-up. I wouldn't have expected such a marked difference in an 8x.

On a couple of occasions I've tried the whole IS range, including standing on the shaking platform Canon bring along to shows. (In my case at least that served to emphasise the limitations of the IS mechanism). There was a small discernible reduction in shake in all with possibly the 10x42 being the best but I certainly wasn't getting that kind of improvement in detail you're suggesting. Unfortunately the weight, balance and general ergonomics meant that some models were significantly less steady than my usual pairs even with the IS mechanism engaged.

I'm supposing we all vary in the strength and frequency of the tremors that are transmitted to the view. I suspect in my case its mostly a tremor in the hand caused by a poor balance that the IS has difficulty cancelling. It appeared to be fine with the lower frequency through the arms but that seems to be much less of an issue for me. I'm glad it works for you, and clearly a large number of others, but on the evidence so far, not for me.

David

. Hi David,
A happy New Year to you and everybody else.

Although I say that the improvements in resolution with the 8×25 is 50% to 70% with the stabiliser on, this is not the whole story.

Although with a good and much larger 12 times or 13 times binocular I can equal the resolution handheld, this is for short periods of time.
With the 8×25 the 50% to 70% improvement is all the time that the stabiliser is on.

So in actual use I would say that the resolution of detail even for a static target is almost 100% and for a moving target such as an aircraft certainly 100%.
The proof of the pudding is in the eating and I was very surprised to see the aircraft carrier's name on the side of the aircraft extremely easily with the stabiliser on and quite unreadable with the stabiliser off.

The last 8×25 I tried a few years ago from memory was not as good as this one but it may have had a different stabiliser system.

I don't know why you don't get better results from the Canon stabilised binoculars.

At night with the 18×50 looking at an aircraft several miles away each window is easily seen and even the shape of the window. I would say that the improvement in resolution is two times the three times better with the stabiliser on.

I've been using Canon stabilised binoculars for about 15 years and I have briefly tried many others including the most peculiar Russian one that took more than a minute for the gyro to speed up before sending itself up into orbit. And it is also very noisy. It is military, so quite daft. Although it is so bulky it would stop a bullet.

However, many standard non-stabilised binoculars give much brighter images than the Canon stabilised and standard binoculars are probably much better for birdwatchers although some birdwatchers seem to like the Canon 10×42 L I S.

As far as I'm concerned stabilised binoculars should be the norm with affordable lowlight level electronic binoculars of high capability next.

Also for me I would think that any of the Canon stabilised binoculars even the 8×25 can probably equal the resolution of any handheld standard binocular.
However, if you mount the standard binocular on a tripod that is quite a different story but I hate tripods for binoculars.

The previous 8×25 Canon image stabilised binocular had the front optical window fall off. It is only held on with a thin plastic front retainer and unfortunately my hands are not good enough to sand it down and glue it back on so it has not yet been repaired.
It works without the optical window but of course this is not correct. But it gave about five years very good use for watching cricket matches etc. It was not actually properly attached even when new. And it had hard use before the optical window detached itself.

You are probably right that I would see more advantage with longer periods of use.

I've not tried to measure the effective resolution of a Canon IS but I have both hand held and tripod mounted for a number of my binoculars. Unfortunately I've misplaced my notebook for now but from memory I get little difference with my 7x36 where hand held would be about 6.5 equivalent. Above that it very much depends on the balance of the model. An 8x42 might be as low as 6.5x or better than 7.5x. One 10x I have gets me over 9x hand held and another 6.5x. My 12x porro gives me about 10.5x hand held equivalent. So shake accounts for something between 8% and 35% loss in detail depending on magnification and most particularly the balance of binoculars.

I don't know why the IS didn't appear to do much for me but even with the 10x42 I really don't think I was seeing the detail level of my best 10x42.

David

. Regarding using test charts to assess the difference between a tripod mounted and handheld binocular.

David states that the loss of resolution is probably between 8% and 35%.
So the gain using tripod mounted binoculars compared to hand held binoculars will be between about 9% and perhaps 53%.
An arithmetic mean of about 31% and a geometric mean of about 22% roughly.

But I don't think this is the whole story.
When a binocular is tripod mounted one can see the fine detail almost continuously.
When binoculars are handheld the finest detail is only seen momentarily or for a very short period of time.
These differences do not equate to how one observes in the real world, however, either astronomically or in birdwatching.

In astronomy it is well known that if a discovery is made with say a 16 inch (40 cm) telescope, the object will then be able to be seen it in a 10 inch telescope and eventually in a 6 inch telescope by the same observer in each case under the same conditions.

There is a vast difference between finding unknown detail and seeing well-known detail such as an intimately known test chart.

I was really quite amazed when looking at the aircraft at 2 1/2 miles. With the 8×25 binocular with the stabiliser off it was a nice looking side on view of the aircraft.
When I pressed the stabiliser button the aircraft carrier's name magically appeared in large letters on the side of the fuselage. I had noticed nothing on the side initially.
Once I knew there was writing on the side I could just see there might be writing on the side with the stabiliser off but it was quite impossible for me to read it.

Getting back to astronomical observations, I used to use something called Astro cards for finding very faint objects in the sky. These showed exactly where the object was and I could see objects four time fainter using the cards than using a normal sky map. If one knows exactly where something is it is very much easier to find.
The same goes with seeing the planet Venus in the daytime. It can be seen easily with unaided eyesight on a transparent day but only if you know exactly where it is. It is almost impossible to find just by scanning the sky.

I think that I am about average in being able to handhold binoculars. I do have pain in my hands but this does not affect the steadiness of my hands although I do try to limit the time that I use binoculars.
My rest pulse is 58 per minute and my blood pressure 125/75, which is not bad for an antique.
I don't know what causes handshake, whether it is ones pulse or breathing or both or something in addition.
Obviously it varies from person to person.

I don't think the Canon would have produced a range of image stabilising binoculars if there were not very real benefits to users, although obviously not everybody gets on with them.
They would not make complex binoculars that are heavier and bulkier than non-stabilised binoculars if they did not give considerable gains.
But the real gains are in steadiness, resolution, small star images and very good edge performance with the better models.

I stick with my figures for the 8×25 of gain for myself of 50% to 70% and sometimes more with static objects and at least 100% for a moving object like an aircraft.
It is not as if I am unfamiliar with aircraft, I have made well over 200,000 aircraft observations, although I am not as up-to-date as I should be.
Also, I have been observing astronomical objects daily for longer than I would like to admit.
I'm not, however a birdwatcher and only have a rudimentary knowledge of birds.

Binastro,

This was a very good post from you. The examples you give of seeing something first in a 16" telescope and then being able to see it in progressively smaller ones, and the example of the Astro cards (which I had not heard of) clarifies and even to some extent quantifies a phenomenon of perception that I have been aware of but have not thought through sufficiently. However, having now used stabilized Canons for over ten years, I have experienced first hand countless of times the effect you describe when looking at something first without and then with the stabilization, and then again without.

David,

I have once visited Birdfair, many years ago, and there went to the Canon stand and saw their impressive vibrating platform. Of course, I had to stand on it and try it. I thought it quite odd that Canon would have thought that was the way to convince people of the usefulness of their IS, since the movement of the platform seemed to be too large in amplitude to be effectively countered by the stabilization. In addition, at least one of the binoculars (an 18x50 IS if I remember correctly) they had on display there was a really bad sample that had truly terrible optics.

I can only guess why you would not get substantial benefits from the IS in your trials of the Canon.

Firstly it is possible that you have much more stable hold of the binocular than Binastro or myself, but reading his description of his hand-holding abilities in above post and knowing my own physique, I'd be surprised if that was it. Incidentally, for several years I have been planning on doing a series of tests on hand-held stability, comparing different viewers, binoculars of different weights and weight distributions, as well as the effects of using finnsticks. That would shed some light on the range of variability in peoples' ability to hold their bins steady. I have the test methodology pretty much thought out, but it would be rather time consuming to do and so haven't gotten around to it yet.

Secondly, and this is very difficult to assess, it can be a question of differences in perceptual speed. People differ in how long a fraction of a second they need to consciously perceive detail. When I was a young student, I participated in a test of a pharmaceutical product, and at the lab we had to repeat a battery of tests after ingesting some nondescript pills. Among the tests, there was one where we were shown a vibrating pattern, and were supposed to press a button when the pattern looked like it was no longer vibrating. The maximum frequency at which different individuals saw the pattern as vibrating rather than still would differ, and for the same individual it would differ depending on how the drug affected your nervous system. They would not tell us exact results, but I recall being disappointed that I did not have the highest scores of the group. Anyway, if we assume equal amounts of shake, it would seem reasonable that a person with faster visual perception would be less compromised by the shake and able to detect smaller detail.

Thirdly there is the question of what you consider detail seen. Especially if you are looking hand-held at something like the USAF bar target, if you concentrate hard enough and view for a long enough time, eventually you will be able to catch a glimpse of the line orientation of a pattern very close to that you would see tripod-mounted with that same instrument. And, like Binastro said, as soon as you have seen it once, it will imprint itself in your brain and seeing it again will be easier in the very near future. For me though, typically I can see about two elements smaller with IS or tripod than simple hand-held with a 10x42 binocular, irrespective of whether it is the Canon or anything else. And like in Binastro's example of reading the text on the side of the airplane, if I'm trying to read text at backs of books on a distant bookshelf, CD's on a record shelf or something similar, with a hand-held binocular I need to be much closer to actually read, while at a distance where reading with IS is easy and effortless, without it or with a binocular that lacks it, I have to struggle to decipher individual words. The same goes if the task is counting the number of anything.

The fourth explanation concerns quality variation in the binoculars themselves and whether or not they have fresh batteries. I know from your own accounts and tests that you have very good eyesight and are readily able to see if a binocular has substandard resolution. Therefore if you view with a mediocre sample you will not be satisfied with the image. And since the stabilization removes an essential impediment from studying the image, you effectively get to scrutinize the flaws of the binocular in greater detail without having to put it on a tripod. It is possible that with your acuity, you would not be satisfied with the sharpness of anything less than a good-excellent specimen of the 10x42 IS L, and you might not have seen one yet. If you do find one that looks good on a tripod with IS off, make sure to have fresh batteries in it before you evaluate the stabilization.

If you are interested, you can propose a test scenario that you could do with your best 10x binocular both hand-held and tripod mounted, and I could duplicate to the best of my ability with a Canon 10x42 hand-held, IS, and tripod-mounted.

Kimmo

You both make very good and relevant points that I wouldn't dispute but I simply haven't spent enough time with any IS model to know what applies in my case. I can only reiterate what I said earlier in that I found the benefits marginal at best. In fact I asked the rep to check for me whether a couple of samples were actually working as pressing the button appeared to have no effect at all. I'm more than happy to accept that I might be an exception and the majority really do benefit from the Canon version of IS.

Kimmo, can you PM me with what you have in mind for the 'shoot out'?

David

. Kiitoksia paljon, Kimmo,

. In the example of the 16 inch telescope used for discovery or first sight and then being able to see the same object in a 10 inch telescope and a 6 inch telescope, in actual fact the object was eventually seen in a 4 inch telescope. And there are many similar examples.

The Astro cards were great and I think they now exist in an electronic version but the physical cards were wonderful for Messier and non-Messier objects.

It is very important with the Canon image stabilised binoculars to have fresh batteries.
The user of the 8×25 didn't even realise his battery was exhausted.
And I've often, with my excellent 18×50 Canon image stabilised binocular realised a bit late but that the battery was draining down.
The optical quality and stabilisation of these Canon image stabilised binoculars does seem to vary, and I think that the 10×30 has had several changes in stabilisation method.

It may seem strange that I see a 100% or slightly more improvement in reading the carrier's name on the side of the aircraft with the 8×25 binocular with the image stabilisation on or off. This was in good light. I even I think that I saw colouring in the individual letters.
It is quite probable that a top quality 8×32 binocular would improve the performance of the 8×25 binocular with the stabilisation off with unknown detail but I'm pretty sure it will never equal the performance of the 8×25 binocular with the stabilisation on.

It may be that an Olympic athlete, either an archer or shooter, or person skilled at meditation may be able to hold ordinary binoculars very steadily.

I think that with unknown detail, the eye cannot reach the finest level of resolution that it can with a known object.

Visual perception is a complex subject and is not evaluated just by using test starts.

As to the speed of perception, when I was young I could identify aircraft in 1/10 of a second or less with probably 90% accuracy. In those days there were very many different shapes and types of aircraft. Nowadays, many aircraft look the same and it is much more difficult to identify them quickly, but something like a Boeing 747 I could probably identify still in 1/10 of a second.
So it is familiarity with the object you are looking that the brain recognises.

But there are numerous mistakes, such as the belief by famous astronomers that the planet Mars is crisscrossed with man-made canals. Just wishful thinking.

. Today, sky conditions are good and there is a large protected unaided eyes sunspot.
Again, I have been observing these for decades.
For people not skilled at solar observation the only safe way is to project the image with perhaps a cheap and nasty 10×25 roof prism binocular onto white card. Don't risk damaging the eyepiece of a good binocular. And never risk your eyes.

I would like to recommend that the administrators of this site repost the interchange between Binastro and Kabsetz as a sticky for the binocular forum.
We have here the most cogent discussion ever posted on BF of the influence of 'human factors' on our seeing experience, factors that are quite real yet very difficult to factor in on a broadly applicable basis.
Adequate recognition of these differences might at least increase the understanding that binocular performance is a very individual experience.

The only additional factor I would venture to add is that of product variation.
Surveyor and Henry Link have both pointed out repeatedly that +/- 20% in performance is realistic for alphas. That difference may not be obvious to all, but it surely is for some on this forum.

typo said:

You both make very good and relevant points that I wouldn't dispute but I simply haven't spent enough time with any IS model to know what applies in my case. I can only reiterate what I said earlier in that I found the benefits marginal at best. In fact I asked the rep to check for me whether a couple of samples were actually working as pressing the button appeared to have no effect at all. I'm more than happy to accept that I might be an exception and the majority really do benefit from the Canon version of IS.

Kimmo, can you PM me with what you have in mind for the 'shoot out'?

David

Click to expand...

David,

I can PM you on this also, but can just spell out here the main features I have in mind. I have the Edmunds 1951 USAF ES Magnifier Quality Resolution Chart as well as the Edmunds USAF glass slide as bar targets, and indoors cannot easily get to a distance greater than 11 meters. So the simplest way would be 10 or 11 meters distance, tripod, hand-held and, for me, stabilized hand-held. I would suggest focussing and setting the diopter first with the binocular on the tripod, then taking a rest and drinking a cup of coffee, and then doing the hand-held resolution evaluation viewing with both eyes simultaneously at exactly the tripod distance and without adjusting either the focus or the diopter that were set on the tripod, but allowing yourself to move slightly away or towards to optimize the focus if needed. Then another short break, and then the testing on the tripod, again without touching either the focus or the diopter. For the hand-held test, I'd like to suggest a time limit, such as 1 or 2 minutes, but am open to suggestions on this. Between these two, and with another break in between, I'd do the IS engaged testing, with the same time limit. I can duplicate the procedure with a Nikon 10x42 SE and a 10x50 CZJ Jenoptem, all of which I own. Feel free to suggest modifications and improvements on this protocol, this is just intended as a start.

Kimmo

I checked photos of the airline carrier's aircraft and I did indeed see the colour of the letters with the 8x25 with the stabiliser on.
I thought they were probably yellowish, when they are actually I think Gold, but close to what I saw.
Without the stabiliser I could not read the name at all or see colour.
I have a lot of experience with colour shades from work and astronomy.

Kimmo,

That sounds straight forward enough but I might skip the coffee.

I would suggest that we probably need to consider light levels as well. I normally try to do my testing with outdoor light levels around 3-4000lux or chart levels about 300cd/m2 which is where my eyesight is at it's best. Even a cloud going over can drop my acuity by 10 to 20 arcseconds and indoor testing is really a non starter for me and would totally mask any differences due to shake (I know, I tried earlier). If you don't have a meter then direct sunlight an hour or so either side of midday should be somewhere close this time of year. With the weather forecast as it is I might have to wait a day or two for sunshine though.

David

Not much Sun in Finland at this time of the year, or at least the Sun is very low. Also snow cover drastically changes illumination.

Binastro said:

Not much Sun in Finland at this time of the year, or at least the Sun is very low. Also snow cover drastically changes illumination.

Click to expand...

You are quite right, I should have checked. Helsinki is about 5* further north than I thought it was.

David

Yes, if I were to wait until there is bright sunshine outdoors, I might have to wait for a month or two. I have a couple of pretty bright lamps, however, and especially the glass slide target I can now back-illuminate well enough to be certain that inadequate light levels are not the limiting factor at least for exit pupils above 0.5 mm

The target in my setup is placed right by a large west-facing window, so when there is sunlight, the indoor light level for the target is very close to outdoor light levels.

Kimmo

. If I were to do tests of binoculars both tripod mounted and handheld I would not use test charts as these consist of known detail.
Usually, when discoveries are made, they are of unknown detail.

So I would try to get as close to perceiving unknown detail as possible.

I thought that maybe one should construct 100 words consisting of five letters but with no meaning and use these at different distances to find out at what distance they could be accurately made out either with a tripod mounted binocular or a handheld binocular.

There may in fact be such systems that opticians use but I'm not aware of them.

Many years ago I was with my cousin in the Street and I said I had quite good eyes, and I asked him how far he could read the number plates on cars that were parked on the side of the road. I read them out as far as I could and I was totally amazed that he could read number plates up to almost exactly twice the distance I could.
My eyesight was 20/15 and I didn't wear glasses. Now I still manage 20/15 or 24/16 but I need correction glasses.
My cousin's vision was about 20/7.5 or in metres about 6/2.2.

So what I would do testing the binoculars is to find a very large car park such as at Bluewater or alternatively a long road with cars parked all the way along it.

I can see numberplates up to about 50 m although I cannot quite remember the exact figure. So my cousin could just read number plates up to about 100 m.

For a tripod mounted very good 10 times binocular one might need a road 1000 m long with cars parked along its whole length.

One would need an independent third party with a good spotting scope, say 20x to 60×80 mm to check the correctness or otherwise of the person using the binoculars.

It might be for instance that the observer could see numberplates up to 700 m tripod mounted and 400 m handheld.
Slight correction might be needed as the angle at 700 m might be 15° and at 400 m 25°.
Ideally, the observer should be at right angles to the number plate.

One would need one or preferably two high quality laser rangefinders either binoculars or monoculars to check the distance to the number plates seen.

I know that tests of number plates do not equate to tests using test charts, but at least one is checking unknown detail as opposed to known detail.
It is not quite unknown detail as one can guess some of the numbers or letters on a number plate.

Analysing and designing out observer bias has been a significant part of my professional life and I quite understand the point you are making. I'm probably more aware of the dangers than some but it's almost impossible to avoid it completely without 'blinding' the study.

Unfortunately I don't think it's practical to go to the lengths you suggest, particularly at two remote sites. What I would normally do for my own tests is simply randomly change the distance between observations so I couldn't predict a result, but I recently discovered a complication. I had been using anything between 7m and 30m and had a feeling that I was getting better results at longer range but the differences were small. Recently a forum member was kind enough to donate a better chart which allowed me to get down to 2.5m, (which would be great for indoor testing) and it became totally obvious that I was getting poorer resolution results at near focus than longer range with a new acquisition. I was waiting for better weather to retest all my roof binos to see if the phenomenon is more widespread. I'll stick with 10m+ for this comparison.

David

Some degree of observer bias is unavoidable, but both David and myself have quite a bit of experience by now of viewing bar targets, and since the test we are contemplating does not really have to be dead serious, I don't think it is going to be too much of a problem.

If you try to do binocular resolution testing with two-eyed viewing at close ranges, parallax error becomes an issue, less so for roof-prism or reverse porros, and much more so for traditional wide porroprism binoculars. Even ten meters is a bit short for the latter, but with good ones such as the 10x42 SE it works pretty well.

Kimmo

The rain we've had for a few days has stopped and after a very foggy start it cleared after lunch and I tried a few readings. The ambient light (needed to contract the pupil) and target illumination (contrast) where way below what I would normally use for testing, but with little prospect of an improvement in the next few days I thought I'd post the results anyway.

I initially used 10.5m, but the light (and results) improved a little to about 2000 lux when I had moved the chart to 28.5m and it's those I'm reporting. I used two binoculars, my Zen Ray Prime 10x42 which I consider one of my steadier pairs in my hands and also my Vanguard Endeavour EDII 8x42 which I don't find so steady. In previous boosted test results the Vanguard gave slightly better full aperture and stopped down resolution results than the Zen Ray, but I would not expect to see any difference at these light levels.

Zen Ray Prime 10x42

Tripod mounted, pattern 0,1 @ 28.5m which gives 7.2" (apparent VA 72")
Hand Held, -1,4@ 28.5m which gives 10.2" (apparent VA 102")

I should say that I felt I was struggling with the light levels and taking longer to decide a reading than I normally would, though still kept within the minute Kimmo suggested. The Tripod mounted apparent VA is about what I expected but the hand held is worse. This works out as a 42% decrease in apparent VA which is a rather larger difference than I've previously seen for this binocular.

Vanguard Endeavour EDII 8x42

Tripod mounted, -1,4 @ 28.5m which gives 10.2". (apparent VA 81.6")
Hand Held, -1,1 @ 28.4m which gives 14.5" (apparent VA 14.5 116")

This again works out as a 42% decrease in apparent VA which is only a little more than I've seen previously. The light had dropped a little more by the time I did this test.

I intend to repeat this, if or when we get better weather.

David