I have found that Tamron 70-200 are unable to nail focus in Live View on K-5. Why? I never understood. Always back or front focus. But OVF no problem.
Then there is the problem that when you focus the lens it is fully open and if stopped down when shooting there may be a shift in focus, called focus shift. I have had that on a couple of lenses. The OVF focus knows this and compensates while LV focus seeks maximum contrast.
---------- Post added 06-02-21 at 05:58 PM ----------
Originally posted by Clavius Ok, this morning I did some more testing... Some suggested to use the select focus instead of spot focus and I wanted to quickly try that. At first I thought that that resolved the issues. Which is great of course! But when I returned to spot focus again I could no longer reproduce the error?! I cannot just let that go and forget about it without knowing what caused it.
Only after some more extensive testing, trying to reproduce the error, it came back. In both spot AF and select AF. I also noticed that the colors in photos taken with LV seem desaturated in comparison to photos taken through the OVF. It can also be seen in the test photos that I posted earlier in this thread.
This maybe a stupid theory of mine, but could it be caused by the sensor heating up? Or because it's used longer in live view mode? In live view the sensor is used to feed information to the screen constantly. But when using the OVF it is "resting" until the actual picture is taken.
I find this so strange, because in my K-5 I am so used to AF in live view being much more precise. There it would seem the other way round.
Are you shooting in strong light and using LV you may get light leaks through the viewfinder. Make sure to always cover the OVF.