Blurred images on the EOS R6

curiousgeorge wrote in post #19484935
As you will see something within the camera seems to be shifting over this half second period.

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I notice this when the IS is on even when my camera is on a tripod. Try testing with in camera IS off, then another test with IS off on the lens if it has IS... please keep us posted.

Archibald wrote in post #19484957
With my R7, I'm noticing that the focus sometimes goes to high contrast elements near the eye instead of the eye. The eye algorithm finds the eye but then illogically focuses on a nearby item. This happens most with distant subjects that are low contrast with high contrast stuff near the eye. It is inconsistent though.

With better subjects the AF works very well.

In your examples, it looks like the focus is drifting to the high contrast background.

Check out this thread. https://photography-on-the.net …read.php?t=1528​487&page=1

Thanks for the link to that thread, it's good to see other users experiencing the same issue. The main points from that are that the selected focus point is not necessary what the camera is focussing on, and the focus point square is much bigger than it appears in the viewfinder. I still wouldn't expect focus to drift off though, seeing as it's done the hard part and found the eye in the first place, especially when the subject is stationary.

siginu wrote in post #19485359
Look at the uppermost twig on the right side of the bird in the last photo, it's suddenly in focus. It's just focus shift in this case.

It's just hard to get my head around it losing the focus on the eye when it had originally locked onto it. That shouldn't happen with a stationary subject in the space of half a second, should it?

Leigh wrote in post #19485326
This is interesting.

I downloaded the files and processed them through Adobe's DNG Converter to .dng files, and viewed them in Photoshop CS6, and I didn't note any specific blurring?

Thanks for taking the time but, really? Did you see the pigeon in IMG_95145, and the parakeet (IMG_9301)?

Overread wrote in post #19484968
This can be tricky because if you check the sharpening tabs on almost all RAW software, they all apply some sharpening by default. A RAW shot with zero sharpening often looks soft even when well taken. Thus even though sharpening is a destructive element to image data and typically saved till the last stage (or done on separate layers). With RAW shots you have to have some applied to have a shot so that you can functionally make choices regarding which shots are sharp and which are soft and to work with the shot in general.

So yes between different RAW processing packages you will see some variations in sharpness, partly the result of the different code they used to process and partly because of different default base values.

I do use Faithful mode in camera, but even then, I'd be surprised that RAW files would not be sharp straight from the camera? I see pro bird photographers on youtube doing the initial assessment of their images in Faststone (eg the brilliant Jan Wegener) which shows perfect sharpness. I can't do that, I have to import into LR to get a better representation of sharpness. Maybe he sets his in-camera sharpness high? I can have a play with the sharpness settings if that's what I need to do.

---------------

What I suspect is, now that I've discovered eye tracking, I'm using it almost exclusively (because it's so amazing), even with static subjects. And the message I'm starting to get is that this is not advisable, as the AI servo mode combined with tracking can be erratic with stationary subjects. WIth my DSLRs I was shooting one shot focus and recompose pretty much all the time, which is probably a more reliable method.

Is the general rule to not use AI servo and/or tracking on stationary subjects, regardless of whether or not the background is busy?

curiousgeorge wrote in post #19484935
The last four images of the burst are below. As you will see something within the camera seems to be shifting over this half second period.

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FOCUS shifted to the rear, as evidenced by the background twig to the right of the subject bird...out of focus in shot 1, in focus in shot 4

I have the same question as OP...why is it that while using Eye Focus and Servo focus on a subject which is not changing distance from camera, does the focus shift?! What setting of the camera influences this behavior, so that focus shift during a sequence of frames is eliminated?

My best guess for an answer to this, from what I can deduce from the above, is:

• AI servo and/or tracking is NOT suitable for static subjects, especially when there's a busy background
  
• Although the focus point shows as being locked onto the eye, the ACTUAL focus area is much larger, and has picked up one of the surrounding twigs as well, so anything within this larger area could be focus-shifted onto when in servo mode
  

i believe this is another good argument for back button focus. Servo focus is not perfect for static objects as the camera will keep grabbing and releasing focus (i don't know why it does this, but I believe that's just the way it works). Changing the focusing system to another button allows you to stay in servo focus mode, but stop the system from working (by releasing the button) once you've locked onto your static subject.

For the record, I do not use back button focus, but rather have C1 and C2 setup for the 2 different scenarios (servo-faster shutter-higher ISO vs single shot-slower shutter-lower ISO), and I just adjust the knob as i need to.

kmilo wrote in post #19486772
i believe this is another good argument for back button focus. Servo focus is not perfect for static objects as the camera will keep grabbing and releasing focus (i don't know why it does this, but I believe that's just the way it works). Changing the focusing system to another button allows you to stay in servo focus mode, but stop the system from working (by releasing the button) once you've locked onto your static subject.

For the record, I do not use back button focus, but rather have C1 and C2 setup for the 2 different scenarios (servo-faster shutter-higher ISO vs single shot-slower shutter-lower ISO), and I just adjust the knob as i need to.

Yeah using backbutton focus with servo focus is much quicker and easier than changing the focus type on the fly between one shot and servo. Esp for situations like wildlife where you really don't want to have to dip into camera menus or change modes because that still bird can be flying in a second.

So using backbutton lets you focus, lock and then release your thumb and the focus will sit still on the subject even with a half press on the shutter button.

Once you get used to backbutton it becomes second nature, tough there's a learning period where you have to get used to the decoupling of the shutterbutton and focus engaging.

kmilo wrote in post #19486772
Changing the focusing system to another button allows you to stay in servo focus mode, but stop the system from working (by releasing the button) once you've locked onto your static subject.

This issue with that is, as discussed above, that you can't be sure whether the AI servo focus has locked onto the subject you think it has. So better to stick to one shot if it's a static subject.

I'm still in two minds on removing the focus from the shutter button, it's much more comfortable holding it down for long periods while you're servo focusing. I prefer to use the AF-On button for one shot spot focusing.

curiousgeorge wrote in post #19486783
This issue with that is, as discussed above, that you can't be sure whether the AI servo focus has locked onto the subject you think it has. So better to stick to one shot if it's a static subject.

But one shot can also focus on the wrong subject. And it is pretty difficult to judge critical focus in the viewfinder.

Can’t you hit the magnify button to get the 5x and 10x loupe to check focus after you are done with AF?

TeamSpeed wrote in post #19486797
Can’t you hit the magnify button to get the 5x and 10x loupe to check focus after you are done with AF?

You can press Magnify during the review, and it will by default magnify 10x, and usually show the critical area. Very handy. However, not sure if we would want to that for every shot.

Not sure if magnifying is possible before the shot is taken.

It does work, I use that during macro shooting, to see if I have whatever I am trying to shoot might be in focus. Of course macro shooting comes with complications of thin DOF and the slightest movements.

Archibald wrote in post #19486787
But one shot can also focus on the wrong subject. And it is pretty difficult to judge critical focus in the viewfinder.

Can it? I suppose if your intended subject is smaller than the spot box, but that would be rare. Unlike servo it won't jump around constantly, or at least that's the theory.

Archibald wrote in post #19486807
You can press Magnify during the review, and it will by default magnify 10x, and usually show the critical area. Very handy. However, not sure if we would want to that for every shot.

Not sure if magnifying is possible before the shot is taken.

Not in tracking mode, otherwise yes you can on the screen, but that works best in landscape photography when the camera is on a tripod. But then I use manual focus and this problem goes away!

I don't like reviewing images in the field, I'd rather be shooting.

curiousgeorge wrote in post #19486810
Can it? I suppose if your intended subject is smaller than the spot box, but that would be rare. Unlike servo it won't jump around constantly, or at least that's the theory.

I practically never shoot one shot, so I'm not sure. But I've gone to one shot when the AF is struggling and wasn't able to get better focus.

Yeah, there are probably ways, but only in some modes, and not the way I shoot.

Yes, exactly. Most of the time the focus is accurate. I do whole studio sets and every shot is sharp on the eye. Most bird shots outdoors are also good. But then there are a few that aren't. They are surprises, unexpected. Often I can't tell until I'm at the computer. I do wildlife shooting for fun, so it is not really critical that all are good.

I keep checking for firmware updates. Maybe the AI can be improved.

Archibald wrote in post #19486818
I practically never shoot one shot

Not even in the studio for portraits?

Archibald wrote in post #19486818
I keep checking for firmware updates. Maybe the AI can be improved.

It will be in the R5 mkII

curiousgeorge wrote in post #19486821
Not even in the studio for portraits?

No, I used to shoot in BBF in servo (with the R5)... now doing shutter button focus, servo. Hand held. I don't want focus errors due to motion of the subject or the camera.

It will be in the R5 mkII

Maybe!