I have often read online that people say Fuji cheats with ISO and the images from Fuji are constantly darker than with other cameras. Additionally I've read that Full Frame intrinsically gathers more light (this is kinda fallacy, but more on that later). So I decided to do a little test by photographing the world's most interesting subject… my wall (I don't own a TV currently so staring at the wall is a new hobby of mine).
I'll be using my Xpro2 (therefore these results should apply to all the modern cameras) and my 1DsIII.
The Xpro2 has a 23mm f/1.4 lens attached.
The 1DsIII has a Sigma 35 1.4 lens attached.
I know ideally I'd adapt the same lens so differences in lens design (glass thickness etc.) don't affect the results. However, for this simple test I'll forgo being super scientific (also I don't own an adapter that'll work).
NOTE: Apparently the camera I compared to (the 1DsIII) is the last camera in which Canon "cheated" as much as Fuji. Still, this just would mean Fuji aren't cheating any more than any other camera maker has/does.
Red is the Fuji Histogram, Aqua is the Canon.
Not enough difference to write a blog post about (but I'm gonna keep going anyway).
So, they're not cheats? Surely they're doing some sort of manipulation to make them match! I mean this is heresy, suggesting Fuji aren't cheating!!!!!!
Actually yeh, ISO itself is manipulation in a way. The makers decide which standard they're gonna follow (there's two of them) and they follow it. Why then do Fuji have a reputation of cheating with ISO?
As I mentioned above, there's two ISO standards for photography.
This is the standard Fuji and I believe Olympus/Panasonic and some others. It's based on a measurment from a base image/jpeg, which means it's less random and more standard than REI.
So is Fuji cheating? I think not. However, why does it seem that some people have exposure mismatches? I think maybe Fuji have slightly changed their settings (maybe switched to REI) in the newer cameras. Perhaps this exposure mismatch is more an issue with the older sensor too (turns out this is wrong, the fact is the 1DsIII also "cheated" in the past… funny how Canon were never accused of cheating on their ISO).
Full Frame = More light?
Last point, I've heard it claimed by some people that Full Frame intrinsically gathers more light. Well that's kinda true as the opening/sensor area is a bit wider so technically more photons are entering the camera, sorta. But the spread of the light is the same evenness over the image. So there's theoretically no exposure difference.
What's all that nonsense mean? Assuming they follow the same ISO standard, you have the same shutter speed and aperture, then your images from Full Frame or Crop will have the same exposure.
Fuji aren't cheating… not anymore than the other camera makers at least.
Thanks for reading, and as usual, if you disagree with me or have new information for me, I'm more than happy to update the blog post if I'm wrong.
Good, well thought out explanation of this – thanks!
Its good to see this explained in more than just a couple sentences (which I've been guilty of in the past).