Fuji Can anyone refute that Fuji inflates its ISO numbers?

I have made shots where the X100S was less sensitive than the X100, and I have made shots where it was 2/3 EV more sensitive, all with identical exposure settings (manual mode). The major (and only) difference there was white balance, as both cameras use the same lens, so we could rule out different T stops. So unfortunately, I couldn't even tell which Fuji camera was "generally" more or less sensitive than another Fuji camera, let alone other manufacturers.

According to my findings when I compared both cameras, the X100S is less sensitive than the X100, but at the same time it's also more sensitive than the X100. It depends on what you point the camera at and which light you are using. I recommend doing such comparisons with identical, fixed WB settings.
 
White balance only affects the RAW data captured if you are using the camera's metering. If you set all exposure parameters manually and match WB during RAW processing, it's not an issue. You can prove this to yourself by using the same camera and lens with the same manual exposure and two dramatically different WB settings under fixed lighting conditions and then viewing the two RAW files after fixing the WB for both in RAW. They will be the same.

As far as T-stops go, what I'm seeing has been relatively consistent using different lenses, all of which have been stopped down a few stops for testing. It could be that the Fuji lenses are uniformly lower in transmission efficiency, but that seems an unlikely explanation for what I'm observing when we know that manufacturers are given great flexibility in how they designate ISO.

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Indeed, the darker image remains darker once you develop the image in the internal RAW converter with matching WB settings, but that's the only differerence I found during my test. Again, I recommend identical WB settings, it doesn't matter whether they are set in the camera or RAW conversion software.

So I can show from tests that the X100S is both less and more sensitive than the X100. Which is kind of odd, but it reiterates the results from DPR with various cameras, where measured sensitivity isn't always reflected in the studio samples of those very cameras.
 
Again, I recommend identical WB settings, it doesn't matter whether they are set in the camera or RAW conversion software.

Yes, that is essential, and I always do it (in the RAW processing stage). I didn't show the data for WB adjusted images pre-brightness adjustment, but I did examine those data and the qualitative differences in image brightness were not significantly mitigated by WB matching. You can see from the data I showed that even after WB matching, the Exposure sliders had to be set at varying levels to match final image brightness.

So I can show from tests that the X100S is both less and more sensitive than the X100. Which is kind of odd, but it reiterates the results from DPR with various cameras, where measured sensitivity isn't always reflected in the studio samples of those very cameras.

I can't speak to whatever technical error or variance DPR may be encountering, but my results with these cameras are pretty straightforward, and the Fuji is less sensitive overall as a system for a given exposure under any number of lighting conditions when the test is properly controlled (including white balance).
 
Hi, just bought a X-E2. I am loving it.
I've made a simple test: shot a white wall with my Nikon 1 and my X-E2 with the same ISO, same speed and same aperture.
The results: all Nikon images, at all ISO tested, were brighter than the Fuji ones.
The conclusion: I don't know if Fuji is inflating ISO, but for sure my X-E2 is less sensitive than my Nikon 1.

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Hi, just bought a X-E2. I am loving it.
I've made a simple test: shot a white wall with my Nikon 1 and my X-E2 with the same ISO, same speed and same aperture.
The results: all Nikon images, at all ISO tested, were brighter than the Fuji ones.
The conclusion: I don't know if Fuji is inflating ISO, but for sure my X-E2 is less sensitive than my Nikon 1.

Sent from my GT-N5100 using FujiXspot mobile app

Haven't bothered to test and don't care. The Fuji cameras make the pictures I want to make and that's all that matters.

Numbers don't matter at ALL, images do, lol.
 
Haven't bothered to test and don't care. The Fuji cameras make the pictures I want to make and that's all that matters.

Numbers don't matter at ALL, images do, lol.

Numbers can be useful when you're comparing different cameras and aren't able to shoot extensively with each of them. If low light is a big part of what you do and you see all sorts of great images at ISO 6400 but in reality that 6400 is really more like 3200 or 4000, that's useful to know. Once you OWN a camera, the numbers don't help you use it more or better, but when you're considering which to buy, they can help you understand some things about it's strengths and weaknesses... I bought the X-Pro based partly on the high ISO examples I was seeing. And while I loved the camera in many ways, I was more than a little surprised when I found I was getting very much the same level of low light images out of other cameras at ISO 3200 (which was as high as they'd work effectively) as I was at 6400 from the X-Pro. I wished I'd know that BEFORE I made the purchase...

-Ray
 
I think Amin's test is the best so far, as it is a side by side comparison with 3 popular camera models with a varied subject with different colors, etc. and compared both RAW and JPEG's. So it seems to me that the general conclusion to be drawn is that the Fuji somewhat overstates ISO but not that much (1/2 a stop or so.) But that this may vary depending on subject, shooting conditions, etc. so YMMV.

1/2 a stop is not a big deal IMO, but it's still good to know as Ray says. I mean let's say the difference was actually a stop and a half- yeah the image is all that matters etc., but such an incongruence would be seriously overstating the camera's performance.
 
1/2 stop is the diference between a 1.4 and a 1.7 lens; on some systems it is more than 500 dolars.

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Recently got an XT1 and have a 6D and 5D III

I see it like Perhaps they overstate the ISO to allow for the reciprocal DOF, so if you using iso 200 at a speed of say 200 at F4 on a full frame you could shoot at iso 200 at a speed of 200 at f 2.8 on the XT1 and the exposure and DOF should be similar?
 
ISO's just a number.
If it were causing me a problem with getting the right exposure, then I'd worry.
But both my X100s and my XT1 seem to get the exposure pretty much spot-on, even in low light. And there's always exposure compensation and manual control for tricky lighting situations.
So I wouldn't worry about it.
 
ISO's just a number.
If it were causing me a problem with getting the right exposure, then I'd worry.
But both my X100s and my XT1 seem to get the exposure pretty much spot-on, even in low light. And there's always exposure compensation and manual control for tricky lighting situations.
So I wouldn't worry about it.
As the OP, waaaaaaay the hell back when, I wouldn't worry about it either, ONCE YOU HAVE THE CAMERA. The cameras expose just fine, when there's enough light. Where I think actual vs stated ISO is highly relevant information is when you're trying to decide what camera to buy and low light shooting is a big part of what you do. Then, knowing what the actual low light performance is relative to the competition matters. ISO inflation makes it harder to do that... Many have raved about Fuji gear at high ISO and it's quite good - just about the same as most of its APS competition, but not way better as many would have you believe...

-Ray
 
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