Re: Picture sharpness on Canon M6 ii with Tamron 100-400mm
Damn, now I'm wondering whether there may indeed be an issue with the unit.
Worth exploring the possibility for sure, good to do some testing. This video might help with how to test your setup - the summary of it is to have a static object in nice light, take your time getting focus right and trying different exposure settings from various distances. It's full of great advice and tips though so worth the watch. If you want me to do any comparison shots of anything I'm happy to do that too.
Slightly unrelated, but when it comes to exposure settings I love the flexible priority mode (FV). By default it is basically shooting in Auto, but then using the dials you can very quickly lock in specific Aperture, SS, ISO or a combination of them + set exposure compensation and let the camera calculate the rest, it's super powerful.
I do wonder, though, do you keep on pressing the focus button (whether back-button or shutter) while shooting, so that the camera is searching continually?
I have my camera on "Servo AF" and also have "Continuous AF" (In menu SHOOT7) turned on - which means regardless of whether I am actively holding an AF button or not, the camera will constantly be searching for the correct focus. On a tripod this is not needed as the camera isn't moving much you can be more deliberate with where to focus, but as I only shoot handheld the Continuous AF and burst shooting is a lifesaver. With Servo+Continuous AF I don't use back button AF and stick with AF on the shutter. I will admit I've lost a couple of shots due to it hunting for focus at an inconvenient time but there's far more shots it has saved that I would have had no hope of getting otherwise.
I don't really trust it getting it right if I kept on focusing
While you are burst shooting should definitely be letting the AF do its thing. At 400mm and f6.3 as per your latest shot - the depth of field only allows a couple of centimetres at best for it to still be sharp, small movements with the camera or the subjects positioning are enough for previously correct focus to be incorrect. A DoF calculator like this can help illustrate what the limits are (I've updated the values to simulate pixel-peeping rather than overall image clarity).
Is any of this potentially improveable with the tap-in console? Have you used it yourself?
Haven't used the tap-in console unfortunately. I've seen posts on the forum about some people having success but I don't have the experience to say. In my opinion their issues seem a lot more subtle than the examples you have shown.