Panasonic 14-140 sweet spot.

Frasier Krane wrote:

Trevor Carpenter wrote:

alcelc wrote:

Might this be of your interest?

According to the MTF table (unfortunately tested on G3!), it seems that generally f/8 might be the most safe play. @14MM, best at f/8 (from f/5.6 to f/11); @50mm, best at f/5.6 (from f/4.9 to f/8), @140mm, best at f/11 (from f/5.6 to f/11).

Thanks. I think it will be a struggle/impossible for me to get to F11 at 1/3200 sec which is what I was fearing

First and foremost, let me say that the answer to what F-number is best for ANY MFT lens is NEVER, EVER F/11. It has never happened, and it never will. By that point, diffraction has kicked in and substantially reduced IQ.

Second, look at the actual charts on ephotozine.com. There is no significant difference on those charts between f/5.6, f/8, and f/11. When that's the case, wide open is your best bet. This is because diffraction may be causing deleterious effects that the ephotozine.com methodology may not be picking up on.

This brings us to dxomark.com.

http://www.dxomark.com/Lenses/Panasonic/Panasonic-LUMIX-G-VARIO-14-140mm-F35-56-ASPH-POWER-OIS-mounted-on-Olympus-OM-D-E-M5---Measurements__793

If you look at the acutance profiles, the center sharpness is best at 140mm at f/5.6. It's slightly better at f/5.6 than it is at f/8. But the edge and corner performance is overall best at f/8.

So, if you can keep the target more or less in the center of the frame, then there's no practical advantage to stopping down from f/5.6. If the subject could be anywhere in the frame, then f/8 might perform better, but, honestly, f/6.3 or f/7.1 might be all you need to get the edges as good as they'll get.

But, again, with telephoto lenses, I tend to look almost solely at the center performance because I generally don't use these for landscapes but to isolate individual subjects. So, I would stick to wide open with this lens.

Thanks for the explanation