Panasonic 14-140MM lens: F3.5 vs F4 is it worth $100 more?

[videobruce]

I just picked up a Panasonic MFT G7 body only. I want their 10x 14-140MM lens, but I wonder if the extra 1/2 F stop would be worth the difference in price of $100 (used $300 vs $400) between the older F4 and the current F3.5?

This is a general purpose camera, mostly hobby, but I'm not a newcomer. Except this will be my 1st interchangeable lens camera (and micro 4/3's)

Input please.

[tomsi42]

If I remember correctly, the new version is a little bit better optically. Also it is smaller and lighter, so I think it is worth the extra $100.

[videobruce]

I since found a couple of reviews of both. Yes the newer is 1/2 the weight (cheaper materials no doubt), different lens design (doesn't extend out as much at telephoto), zoom & focus rings changed (no rubber, smooth with ribs instead), sharpness is better at 140mm, OIS is changed and smaller filter thread diameter. There is a issue with "motion blur caused by shutter actuation at certain shutter speeds" which is debatable on how much a problem this is. SLRgear had a write up on it in their review.

[tomsi42]

I think shutter blur is more problem caused by the shutter than the lens; but I have also heard it is more pronounced with some lenses.

Fortunately, the G7 has an electronic shutter mode that can help with this problem.