Panasonic vs Olympus EVF

alcelc wrote:

Is it a norm features for cameras?

Not to mention the old film slrs, my 1st digital camera, Panasonic LC5, a 2001 4Mp compact, using ovf has such adjuster. My first evf compact, Panasonic FZ5, a 5Mp superzoom fixed lens camera of 2005, also has it.

The major or only difference could be how powerful they would be.

Anything with an optical viewfinder is likely to have a diopter.  But it seems common to have in electric viewfinders as well.  I've had a few times when I needed to adjust the diopter, either because it got moved, or because I was using different glasses (or no glasses).

AFAIK, all Olympus cameras with an EVF have a diopter adjustment. Similarly the older external viewfinders (VF-2, VF-3, and VF-4) for select Pen/OM-D cameras had a diopter adjustment. Now, different cameras have different amounts that can be adjusted, and different eyepoints.

Note, the E-m1 mark I had an issue that if you used one of the larger diopter adjustments, and the viewfinder was exposed to the sun, it could burn into the viewfinder and create permanent ugly green blobs. When I sent my E-m1 mark I in for its two warranty repairs (non EVF related), one of the things noted was that they specifically checked the EVF for blobs (and the other 2 common problems, strap lug nuts coming off, and the mode dial issues). My brick and mortar store also has an official Olympus cleaning event each year, and last year or the previous year, the guy ahead of me had the green blob issue.

While I never had an issue with the E-m1 mark I EVF (other than trying to use it with polarized sunglasses), I did have the back light fail on my refurbished E-m5 mark I in the middle of a Disney World vacation (fortunately I had bought the extended warranty).