Is the EM5’s Miss-Stated ISO concerning to you?

mpgxsvcd wrote:

I am kind of surprised at everyone's reaction. I legitimately didn't know this was as touchy a subject as it apparently is.

I was very surprised when I saw that the DXO Mark ISO ratings test indicated that the EM5 was over stating the ISO by a full stop for almost all ISO values. I immediately questioned those tests and checked the Dpreview sample images.

There is 2/3s of a stop difference between the GH2 and the EM5 on those images. So I went to a 3rd source(Imaging Resource) and checked their test images as well. Again there was a 2/3s of a stop difference in those images.

1 test may be inaccurate. However, when 3 tests show the same result it sends up red flags to me.

My only reason for looking at the EM5 is for Astro Photography where even 1/3 of a stop could mean my 3 minute subs turn into 4 minute subs. In the end that could mean a 1 hour session could turn into 1 hour and 20 minutes. That is a very big deal to me.

I understand that because I deal with AP it really exaggerates even the slightest difference. However, if the differences are real then I would like to know about them.

I appreciate your answer about the GH2 and EM5 testing the same. That helps me. I like to base my decisions off of as many data points as I can get. However, I still am surprised at the reaction I got.

There clearly is a difference in how these cameras are metering.

For terrestrial work I can see how the difference between 1/1300 and 1/1000 of second wouldn't matter much. However, for long exposures sensitivity is very important.

I really would like to simply test the GH3 against the EM5 myself. However, I don't have the money to purchase one right now.

Telling me your experiences with testing cameras against each other helps a lot. The comments that some people posted insulting me did not help anyone at all.