I'm a committed GX8 shooter, but comparing images at 200 ISO is not especially helpful in doing a comparison. Where differences show up is at higher ISOs: e.g., 6400 and above.
The difference is the same as low iso. 2 stops. People just care more at high iso. And then if they werent pixel peeping and had ever shot film then 25600 on m43 would be a revelation.
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Auto focus is a work of the devil.
I post from a tablet, spelling errors are common, berry common.
Surprisingly, this is not correct! At base ISO, both systems have similar DR. Only at high ISO there is a clear difference.
I learned recently (by comparing EM1 and A7S on sensorgen.info ) that the FF cameras have alot of read noise. Much more than I thought (OK, I knew that Canon sensors have a lot of read noise, but I was pretty sure SONY would do better).
The read noise of A/S is rising significantly below ISO 6400 and because read noise grows with exposure, the DR stays more or less constant at 12,5EV. EM1 read noise is rising below ISO 800 and gives a signal to noise ratio of 12EV as well.
Therefore, EM1 and A7S do NOT have 2 stops difference in DR at base ISO, in fact, they seem to be very similar.
This might explain why so many mFT users are quite happy with their equipment ...
Christof
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OM-D + Sam7.5, O25, O60, O75
O12-40, O40-150, P 14-140
M4/3 cameras do quite well at base ISOs....I am very happy with my GX7.
The A7s is not a camera designed for low/base ISOs .....and yet it does STILL have greater DR than any M4/3 camera to date at base.
The a7s is made for high ISO and as the ISO goes up, so does the difference.....by the time the E-M1 maxes out at ISO 25600 it is MORE than two and a half stops behind the A7s for DR for screen and almost two and a half stops for print at DXOmark.....my GX7 is a little worse than the E-M1 too and is more than THREE stops behind at ISO 25600 for screen and almost three stops for print. The A7s is very usable at ISO 25600 and even higher.
Now if you look at other more regular FF cameras .....my A7 for instance, DOES have about two stops DR advantage at base.....and base ISO is ISO 100 with a boost down to ISO 50 with intermediate settings of 80 and 64 for both the A7 and A7s......M4/3 and I am using ISO 200 as my base for the most part still.....
All three cameras have their uses......the A7s is my low light/high ISO and video camera but it also is very nice in the day time ......surprisingly good in fact.
The A7 is simply better (base ISO).
The GX7 is a nice small camera and I love the tilting EVF and touch screen but it is not the "best" camera for image quality.....no M4/3 is.....they are all good ENOUGH though as far as I am concerned and fit for purpose.
The A7 is not the "best" FF camera either in terms of base image quality....again, it will do me (and I prefer it over any DSLR for other reasons....just as many will prefer M4/3 for "other" reasons).
Choice is good.
There is more to it than DR as well.
. The question being asked in the forum { which crops up nearly every day} is with regard to mFT compared to FF. Which for anyone not hopelessly devoted to mFT is a simple question ,easily answered. If the question was is mFT good enough for almost anything then it is a resounding yes. Despite having an extensive Nikon FF kit my mFT gear gets used the for the majority of my photos. To me mFT are actually a near perfect pair , with each being good where the other is weak.
