crossover37 got me thinking in this thread-
https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/93510-should-i...75-f2-8-a.html that I needed to do a comparison between my new Tamron 17-50 f/2.8 & my 6 year old Tamron 28-75 f/2.8.
Just for giggles I threw the FA50/1.4 in the mix too. These were shot in RAW, opened and saved in ACR (w/no adjustments/crops), resized an saved as jpegs. No post processing except the resize/save.
The focus point was the left edge of the bell of the left bloom. Apparently I need to calibrate the 17-50 since it doesn't seem to be focusing where it should. I knew I bought that Lens Align the other day for some reason.
All shots taken @ 50mm, proving not all 50mm lens FOV are equal.
FA50 @ f/2.8
Tamron 17-50 @ f/2.8
Tamron 28-75 @ f/2.8
FA50 @ f/4.0
Tamron 17-50 @ f/4.0
Tamron 28-75 @ f/4.0
FA50 @ f/5.6
Tamron 17-50 @ f/5.6
Tamron 28-75 @ f/5.6
FA50 @ f/8.0
Tamron 17-50 @ f/8.0
Tamron 28-75 @ f/8.0
There didn't seem to be much point in stopping down any farther than f/8.0 for this subject. The 17-50 seems to have better contrast than the FA or the 28-75, though they all had a hood on for these shots.