47greyfox Loc: on the edge of the Colorado front range

Hmm, I should've done this before my last comment. I took another look at your dng file and my mimic. Adjusting Exposure up by 0.65 certainly didn't cause me to lose the texture of the head's feathers. So, adjusting EC +1 shouldn't have either. Thanks, Paul.

amfoto1 Loc: San Jose, Calif. USA

1. Despite where DPP shows the AF point, it's possible that focus was on the branch in front of the bird, instead of directly upon it. Those red AF indication boxes simply aren't all that accurate. Often the area of sensitivity extends slightly beyond the indicated area. It varies from model to model and even camera to camera.

2. Do you have a "protection filter" on the lens? If so, take it off and try shooting without it. It's not uncommon for a filter to soften images slightly. It also might be amplifying chromatic aberration, some of which I'm seeing in this image. (CA is common in telephoto lenses. And it's one of the key reasons why Canon... and now Nikon and Sony to a lesser degree... use fluorite in some telephoto lenses. In fact, all but one of the Canon 70-200s and all but a couple of their longer focal length L-series telephoto primes and zooms use fluorite. Two or three years ago Nikon started using it in one 70-200 and several telephotos 400mm and longer. I think Sony uses it in two of their super telephotos. It adds cost to a lens and there's no third party lens that I'm aware of manufacturer using fluorite. Sigma uses some "fluorite like" elements, as they call them, in some lenses.)

3. Another problem I see is that this image is underexposed about one stop. That's common when shooting an image with a lot of blue sky... and it's made worse in this case because the bird is facing away from the sun, it's face and much of it's body is shaded. Much of the tree is it's shaded side, too.

4. AFAIK, there is no need to turn off image stabilization on the third party lenses... Same as it's not necessary on most Canon IS lenses. Not sure about this Tamron VC, but I'm pretty sure that Sigma's OS operates very similarly to Canon's IS. Both will turn themselves off when not actually needed, in all but a few lenses. Otherwise, IS can help sharpen an image being shot with a big telephoto, where even the "shake" from the mirror slap or shutter action or a slight breeze can cause some image blur.

5. With an image like this, I would have shot a short burst of several shots, in hope at least one would come out nice and sharp.

6. Your lens might benefit from some AF calibration on your 7DII. This fine tunes the accuracy of focus of that particular lens on that particular camera.

The main thing with an image like this is don't crop it too much and don't judge it while viewing it ridiculously large. The image improves with some basic sharpening and looks quite good in a reasonable size... would print nicely as a 12x18" at 300ppi. It's fine and often useful to enlarge to 100 or 200 or even 300% for precise retouching, but silly to judge the image that large. At 33% it looks good and that is a wee bit larger than 12x18" (on my computer screen at it's native resolution of about 100 pixels per inch). Even 50% view looks pretty darned good. (ANY image will fall apart and look bad at ridiculously high magnification.)

I hope you don't mind, out of curiosity I did some sharpening and exposure adjustment in Photoshop, to see how well it would respond. The results are below. All sharpening and tweaks were done selectively (bird and tree branches only, not the blue sky). This is so that the sharpening doesn't add "grain" to the plain blue tonal area of the sky, where it would be obvious. Any increase on the bird or tree would enhance detail. Unfortunately, the sharpening caused some "blooming" or a "halo" around the bird and the tree. This isn't uncommon and appears as a predominantly white outline a few pixels wide, when viewed at higher magnification. If it were my image I'd do some additional work to mitigate that and the chromatic aberration. Both are fairly easily retouched, I tried it in a few places here, but it's time consuming to do a whole image like this one.

See what you think of the results...

(Download)

47greyfox Loc: on the edge of the Colorado front range

Thanks, Alan. Two, actually three, quick comments. Sigma suggests turning off "OS" when tripod mounted. Yeah, I was surprised. I don't use UV or any other protective lens covering except all have hoods. The other is that the image you worked wasn't attached to your posting? I am always interested in people's workflow and what they do, so if it isn't an issue. Go ahead and post. Thanks!

frankraney Loc: Clovis, Ca.

Alan, very good processing.....about focus point being off...I do not notice if the op was/does use BBF. if so, and he focused and moved/recomposed slightly the focus point will not show correctly, correct?

47greyfox Loc: on the edge of the Colorado front range

I agree. Now, that I see Alan's image. Haha! As for your question, yes, I use BBF almost exclusively, unless LV and manual focusing.

frankraney Loc: Clovis, Ca.

I use BBF almost exclusively and have noticed sometimes in PP that I have move slightly after focus. That is the problem with BBF, you must hold still, which at my age is getting hard to do. Usually the movement doesn't make much difference (maybe a little softness), It just shows the focus point wrong in post.

CHG_CANON Loc: the Windy City

Are you holding down your assigned BBF button for the entire shooting sequence? What you've described is inconsistent with how AI Servo / Continuous AF works. With the AF system active, because your thumb is holding the AF system active by pressing the BBF, any slight movement / change by you and / or the subject will be detected and adjusted by the AF system. The same would apply to leaving the focus on the half-press of the shutter, assuming the AF mode is set to AI Servo / Continuous AF / similar.

frankraney Loc: Clovis, Ca.

No no Paul....I was suggesting that maybe the problem was, if he uses BBF and focuses, then moves or recomposes, in post the focus point will show the focus point wrong, since the camera was moved after focus.

47greyfox Loc: on the edge of the Colorado front range

Hi Frank, I'm the OP. Yes, I used continuous BBF. Held the "AF On" button down and did not recompose. In cases where I didn't hold it down and slightly recomposed, I have seen the phenomena you describe.
Thanks.

frankraney Loc: Clovis, Ca.

If you held the BBF button down, and moved ever go flighty, this would have caused the soft focus you think you saw. It may be real.

Unless you were expecting the bird to take flight, I would not hold the BBF, I would focus and release. Holding the BBF us for moving objects/subjects.

That is why I mentioned this.

CHG_CANON Loc: the Windy City

Keep in mind: best practice is to press and hold, without regard to a static or moving subject. That's why it's called a best practice.

frankraney Loc: Clovis, Ca.

You're absolutely correct Paul. for what I shoot, I'm typically shooting landscapes and stuff that don't move so I'm in AF-S, or single, so I only touch the focus and then let go, if I were going to track a bird or something, then I would put into AF-C and hold the back button focus.

Am I doing wrong?

CHG_CANON Loc: the Windy City

Wrong relative to 'best practice'? That would be changing the AF setting. Instead, set to AF-C and leave it there. Then, just decide when / if you just leave your thumb on the button through the shutter release. Or, press and release the BBF and then release the shutter. You're never caught fumbling with your camera as the situation changes.

frankraney Loc: Clovis, Ca.

Thanks, Paul for reminding me. I'll start doing it this way again. I started doing it this way (best practice), and switched to AF-S because I was having a problem holding steady. Things have changed and I'm a lot steadier again, and just got used to shooting AF-S for the way I shoot.

My thought though, was the photo posted in this link had the focus point slightly below the eye, and could have been caused by movement of the camera. I was thinking maybe after focus, the camera was moved slightly, causing the focus point to show wrong, if the button was released. If held, it would have focused again where the red square is.

imagemeister Loc: mid east Florida

yes, mostly underexposed - with consequences.