williejoha

Make sure that when you rest the lens on the beanbag the focus ring is free and not touching the beanbag in any way. Took me a while to figure it out with the Canon 100-400 lens. Good luck.
WJH

suntouched Loc: Sierra Vista AZ

That's pretty slick.

PGHphoto Loc: Pittsburgh, PA

I would double check if microfocus adjustments are needed on the lens/body combination. I found that newer Canon models have difficulty with 'older' lenses. I was frustrated with my 5DS not seeming to autofocus sharply with my 17-40 f4L . When I did a test using a focusing target at a 60 degree angle, I found the wide end needed a -10 adjustment to bring the main focus point in sharp focus. Similarly, my 70-200 also was off by about the same amount. No problems since then. The same lenses on my 70D were spot on.

bsprague Loc: Lacey, WA, USA

B&H has it. I bought it thinking I would get a lot of use on trip to Yellowstone. Turned out I got out to the RV a lot and use a tripod.

lookingglass18

That’s a wonderful tool!! Thank you.

amfoto1 Loc: San Jose, Calif. USA

It's hard to tell from this example... A larger image with the EXIF intact would be better to analyze and give you useful feedback.

But just guessing from this...

1. How fast was your shutter speed? It's possible some of the problem is camera shake blur. That will be compounded if shooting from a vehicle with the engine running. That causes vibrations that can ruin an image.

2. Do you have a "protective" filter on the lens? If so, try shooting without it and see if your images are sharper. Your example almost looks like it was shot through a window. A filter can cause that. I don't use the Tamron 150-600mm so can't say for certain, but some lenses just don't work well with filters. (The original Canon 100-400mm "push/pull" zoom is one example I know of, that doesn't "play well" with filters. Even a good multi-coated filter will make that lens "go soft".)

3. Also related to the lens.... is it the original Tamron 150-600mm or the "G2"? Again, I don't use them but have heard the original was somewhat "soft" between 500 and 600mm, and that the newer "G2" version of it is sharper in that range. Without the EXIF in the image, we can't tell what lens or what focal length was used. Note: To me the image quality of the two versions of the Tamron lens don't look all that different... https://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=1079&Camera=453&Sample=0&FLI=4&API=0&LensComp=929&CameraComp=453&SampleComp=0&FLIComp=4&APIComp=0. The test shots at that site were done with a full frame camera, so the "corner" sample shots aren't relevant to using it on an APS-C camera like yours.

4. Have you had better luck with the lens in other situations? If so, what were you doing differently.

5. A very long focal length like 500mm or 600mm is challenging to get a steady shot in all situations, but especially so when using it on an APS-C camera, where it "behaves" as if it's even longer!

5. And what aperture were you using? Stopping down a bit makes most lenses sharper (see the above link to test shots), plus a bit more depth of field can make precise focusing less critical.

6. Is that lens compatible with Tamron's USB adapter that can be used to fine tune focus and other things? Alternatively, have you tried the Micro Focus Adjustment feature of the 7D Mark II? Either (or both) of those might help.

7. Regarding the camera, how did you have the focus set up? Single Point focus is the most accurate, but you have to keep the focus point right on the subject where you want camera & lens to focus. If you were using Zone, Large Zone or (God forbid) All Points Auto, the camera & lens can end up focusing on something other than what you wanted. For example, in your image it's a bit hard to tell, but the corner of the fence closer to you might be sharper, which can happen when using multiple focus points and leaving it to the camera to decide where to focus. it will usually focus on whatever is closest and covered by one of the active AF points (in this case, the corner of the fence the bird is standing on). The only time I use multi-point AF is when shooting birds in flight or other subjects against a very distant/plain background that's unlikely to distract the AF system. Even then, you have to be careful... When a large bird is flying past, it might focus on the closest wingtip and the bird's body and head end up out of focus.

8. Also regarding the camera, what focus mode were you using? With a perched bird like that, either One Shot or AI Servo should work... But I usually use AI Servo with wildlife just in case it starts moving. The 7D Mark II is very good tracking moving subjects, when it's set up and used correctly. (I never use AI Focus, which isn't really a focus mode at all... it leaves it to the camera to decide if the subject is moving or not, then is supposed to use the correct mode: One Shot for stationary and AI Servo for moving subjects. Maybe it's better on newer cameras, but when I tried it years ago I found AI Focus seemed to slow focus response a little, sometimes didn't choose the correct mode and sometimes didn't switch modes if a subject stopped or started moving. There are a number of other "tweaks" possible with the 7D Mark II's AF system, but you have to be careful and know what you're doing setting them. (I don't use the focus "Cases" at all... Instead I make my own settings. To me the "Cases" are just added confusion to an already complex AF system. I recommend "keep it simple", at least until you have time to experiment with and learn to use the various "tweaks", one at a time.)

9. Is that image cropped? Can't tell without the EXIF, but you can only do so much cropping before an image starts to "fall apart". A side note... if your camera has seen a lot of use, a sensor cleaning might make images a lot sharper. A dirty sensor reduces resolution and, worst case, can even make for "soft" looking images. That would only be compounded further by cropping an image a lot.

Hope this helps!