-= 90D owners unite! Discuss and Post Photos

MatthewK wrote in post #19040848
In that same vein, I also didn't have any luck with the 600III (with or without the 1.4TC) on the EOS R, whereas everyone else reported being more than happy with the camera + other lenses. I'm starting to possibly suspect that maybe the 600III is the culprit here, and that it might require more power to drive properly. Because really, the only camera I had good usage with that lens is the 1DX2, which we all know has the more powerful battery.

Matthew:

I've been using 600/4s since the FD models, including the original EF and Mark II and III and have never had any problems like this with 4 or 5 different camera bodies. I never heard of any camera bodies having more powerful batteries.

FrankKolwicz wrote in post #19041234
Matthew:

I've been using 600/4s since the FD models, including the original EF and Mark II and III and have never had any problems like this with 4 or 5 different camera bodies. I never heard of any camera bodies having more powerful batteries.

The 1-series batteries have more powerful battery packs.

https://photography-on-the.net …/showthread.php​?t=1457570

FrankKolwicz wrote in post #19041229
John:

I seems like it happens most often at longer distances in wide open spaces. I've been doing mostly waterfowl this winter because of conditions at my usual sites and these tend to be at longer distances with reflections of sky on water. As of the last few days, warblers have started showing up in my backyard and the few images I did today at close range have been fine. I expect to do a lot more in the coming couple of months, so I should be able to test that idea thoroughly.

I don't have answers to the other questions and don't know how to check them or even what they mean, exactly.

I don't recall having the exact problem you are talking about, slight backfocus with good MFA, but those general conditions are also the ones that I and others find the 90D weakest at; when the the subject is far away, and you're trying to focus on it against a busy background. Against a blue sky, BIFs work perfectly, if an AF point is on the bird and it is close enough to focus already that it has contrast. Even if the background is busy, if one bird is large enough to be under multliple AF points, it generally focuses correctly, but not quite as instantly as single-point.

I've wondered whether or not it might be a power issue. If my memory serves me correctly, on some cold days when I haven't just charged the battery, I would get odd behaviour...

Warmish weather now; charging up every evening. Let's hope!!

Cormorant in Breeding Plumage and Violet-Green Swallows in flight. The Swallows were a test to see if it could even happen. Very far away, very fast. Dang!!

More Swallows: Just out testing to see if AF for BIF works on the 90D... Thee shots are in the wild, not near a nest. Second one is blurry but I got the colours!!!

Finally: Blue mouth on the Double-crested. My friend got one the other day of the Emperor. So much blue, so bright. The Emperor wasn't there today; but I got a princeling!!!

John Sheehy wrote in post #19041395
I don't recall having the exact problem you are talking about, slight backfocus with good MFA, but those general conditions are also the ones that I and others find the 90D weakest at; when the the subject is far away, and you're trying to focus on it against a busy background. Against a blue sky, BIFs work perfectly, if an AF point is on the bird and it is close enough to focus already that it has contrast. Even if the background is busy, if one bird is large enough to be under multliple AF points, it generally focuses correctly, but not quite as instantly as single-point.

My problem is not a matter of a missed focus point picking up something extraneous in the image. The single AF point is completely on the subject (head or body), but the critical focus is just behind the point of focus, which can be seen elsewhere on the body or in the water nearby, for instance, for the ducks I've been doing. It does take careful scrutiny or a substantial crop to find this error, sometimes it's hardly visible at 1/2x view on an editing monitor and it would print OK for me with some extra sharpening, carefully done.

Here's an image from today's backyard. In it you should be able to see a distinctly sharp band in line with the eye and rapid softening fore and aft.

Canon 90d/600/1.4x, effective focal length is 1344mm. 1/1000; f/8; ISO 320. The crop represents 23% of total image area. I'm using the smallest single point AF selection, not the full size single point, even though Canon CPS has told me that the small point is not as accurate as the large point (with 5dsR).

The problem I see at longer distances is that the sharp band would be somewhere near the back of the head.

FrankKolwicz wrote in post #19042560
Here's an image from today's backyard. In it you should be able to see a distinctly sharp band in line with the eye and rapid softening fore and aft.

Canon 90d/600/1.4x, effective focal length is 1344mm. 1/1000; f/8; ISO 320. The crop represents 23% of total image area. I'm using the smallest single point AF selection, not the full size single point, even though Canon CPS has told me that the small point is not as accurate as the large point (with 5dsR).

The problem I see at longer distances is that the sharp band would be somewhere near the back of the head.

Hosted photo: posted by FrankKolwicz in
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forum: Canon Digital Cameras

Perhaps this lens needs different MFA values at different distances. That is a need with some lenses, unfortunately, and Canon doesn't provide a solution to it, unless they can take a lens and do something to it that equalizes the MFA need over a range of distances. If the problem is caused by the TC, then there may be no solution, other than live view, or some future OVF AF that has MFA by distance.

One might not even notice this same potential problem with a lower pixel density, because the sensor is incapable of seeing the difference; this is one reason that many people are seduced by the results with large pixels.

John Sheehy wrote in post #19042640
Perhaps this lens needs different MFA values at different distances. That is a need with some lenses, unfortunately, and Canon doesn't provide a solution to it

True, but some third-party lenses do provide exactly this capability. For example, the Tamron 150-600 G2 can be focus adjusted for 6 different focal lengths, each at three different subject distances. Their 18-400 super-zoom has 24 combinations (8 focal lengths at three distances). Sigma has a similar system. Canon's failure to provide this sort of functionality, which by now is not new, is unfortunate. Of course, their manuals still warn you against even using their own, limited AMFA adjustments.

Cooties: Okay ... don't jump on me for the noise etc. The light was horrid. But, have you ever seen an American Coot do this? Lovely bird (they are often so ordinary!!!)

Still getting to grips with the complexities of 90D settings with 100-400mm f4.5-5.6 is usm mk2 to get a clear photo, but this one is the closest I've come to an acceptable image:

Dirty contacts?

I started a new round of tests prior to renting a replacement 90d and sending the problematic one to CPS.

I set up my MFA target and ruler about 40 feet away and ran through settings on every combination of 90d, 5dsR, 600, 300, 1.4x, and 2x. Most required slight changes.

Starting with the 300, the 90d worked properly: it responded to MFA settings at the middle and at extremes as I expected, unlike previous tests with the 600, and it was reasonably repeatable on the proper setting, that is, there were only fractional inch changes around the exact setting and centered on it. The same was true with the 1.4x and 2x and with the 5dsR body.

So, probably not the camera, after all.

Before setting up the 600, I decided that it would be good to give all the contacts on all the parts a mild cleaning with isopropyl alcohol and a cotton swab - 8 sets of them. The swab came away slightly soiled, as expected, the cameras are in the field almost every day, in every kind of weather and the inside of my car is pretty dusty from the gravel roads I travel.

If you're wondering why I haven't done that before now, it's because I have never done it to any of my cameras and lenses in the roughly 30 years that I've been using EOS cameras and EF lenses. Canon may have cleaned them when I sent them in for repair, but I didn't. And, yes, I still have that A2 and a 28-80L lens from 1991 (and a couple of beat-up F1s that date to some time in the '70s) among other things not worth enough to offer for sale.

Back to the target with the 600, the 90d performed as it did with the 300, moving the center of focus back and forth as I changed from +20 to -20 and then set it to the proper adjustment, where it has stayed and variations are as described above.

However, I have not had a chance to test it at longer distances where most of the errors became problematic, causing many discarded images.

We'll see tomorrow, I hope, if I get out for some tests and maybe even real interesting birds.

Thanks for all your attention and comments, I'll keep you posted.