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Inaccurate ISO of Fujis commonly accepted now?

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deednets

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I keep on reading this on various forums but can't quite follow where the reviewers come from here, e.g. the latest in the dpreview review of the X-T1 where it states that the 6400 is more like 4000 on other systems. When you hear this "other systems" you might be mistaken that Fuji cheats and the rest of the world doesn't.

4000 vs 6400 is substantial! However, when I tried to verify this for myself comparing files of a variety of cameras I had and have access to, I can never quite find the massive difference the reviewers seems to find. There was somebody here who used a couple of Sekonic light meters some time ago and found a difference but not as substantial as some reviewers think - and that the standard is not quite as carved in rock as it might sound, e.g. there is Fuji and then there is the honest rest.

An example? I just looked at the little D3 versus X-T1, 85mm on the D3 versus the 56 on the X-T1.

Loading…

www.dpreview.com

The D3 uses F8 and 1/60s @ ISO200, the Fuji uses F5.6 and 1/110s. When you click the 2 images at screen view, the D3 seems to be underexposed by more than the diference between 1/110s and 1/120s.

If the 2/3 stop difference was true (as in the example by dpreview of 4000 vs 6400) then I wonder what's going on with the example re the D3.

I am aware that the ISO curve might not be linear!

Any ideas as to why this will now be engraved for life that Fujis cheat, but I can't really follow? I must be a fanboy, right?? Or maybe the D3 is cheating, some here might remember that the D3 used to be another example for a high ISO capable camera ...

Deed
 
I started a thread recently on this topic here as well because I'm considering a move from Sony to Fuji and noise is one consideration. You might find it interesting.

Loading…

www.dpreview.com

Related, and new, you might find Bill Fortney's comments of interest on his latest blog post.

Loading…

billfortney.com

Be sure to read the comments.

Bill is a huge fan of Fuji and has decades of experience with Nikon, so I personally give his input a lot of credence. He calls the recent Popular Photography magazine's review of the XT-1 noise as hogwash.
 
deednets said:
...

4000 vs 6400 is substantial!
Click to expand...
Well that depends on how you define 'substantial'. It's effectively the same difference as exists between ISO 125 and ISO 200; three quarters of a stop.

It's good to be aware of, but not that much of a big deal really; you can get more than ¾ of a stop 'error' in metering when the scene doesn't average out to a nice, even mid grey. A little twist of the exposure compensation dial will get you where you want to be... All meters need interpretation, this is no different really.

It doesn't really matter how a different camera reacts, you just need to know your own camera, quirks and all.
 
deednets said:
I keep on reading this on various forums but can't quite follow where the reviewers come from here, e.g. the latest in the dpreview review of the X-T1 where it states that the 6400 is more like 4000 on other systems. When you hear this "other systems" you might be mistaken that Fuji cheats and the rest of the world doesn't.

4000 vs 6400 is substantial! However, when I tried to verify this for myself comparing files of a variety of cameras I had and have access to, I can never quite find the massive difference the reviewers seems to find. There was somebody here who used a couple of Sekonic light meters some time ago and found a difference but not as substantial as some reviewers think - and that the standard is not quite as carved in rock as it might sound, e.g. there is Fuji and then there is the honest rest.

An example? I just looked at the little D3 versus X-T1, 85mm on the D3 versus the 56 on the X-T1.

http://www.dpreview.com/forums/post/53495264

The D3 uses F8 and 1/60s @ ISO200, the Fuji uses F5.6 and 1/110s. When you click the 2 images at screen view, the D3 seems to be underexposed by more than the diference between 1/110s and 1/120s.

If the 2/3 stop difference was true (as in the example by dpreview of 4000 vs 6400) then I wonder what's going on with the example re the D3.

I am aware that the ISO curve might not be linear!

Any ideas as to why this will now be engraved for life that Fujis cheat, but I can't really follow? I must be a fanboy, right?? Or maybe the D3 is cheating, some here might remember that the D3 used to be another example for a high ISO capable camera ...

Deed
Click to expand...
Just look at dxomarks. You see the difference between the measured ISO and the ISO from the camera.

There is a signicant difference, it was measured by DPR, dxomarks,... I had seen a comparison between cameras and the Fuji was the camera which was the most overstated.

Every time somebody posts a picture saying: " do you see how good the result is at 6400 ISO !! " it should be mentioned that to be equal/fair with other cameras, we should correct this...
 
Checking DxOMark it's not just Fuji.

The Olympus E-M5 is almost a full stop under it's stated ISO.

Camera ISO 200, DxO measured 107
Camera ISO 400, DxO measured 214
Camera ISO 800, DxO measured 394
Camera ISO 1600, DxO measured 782

The Nikon D7100 isn't quite as bad, but still quite a way off

Camera ISO 100, DxO measured 69
Camera ISO 200, DxO measured 138
Camera ISO 400, DxO measured 279
Camera ISO 800, DxO measured 552
Camera ISO 1600, DxO measured 1118

It would be nice with a clearly defined standard that everyone followed, but since ISO isn't as easily locked down as aperture and shutter speed it's probably not going to happen.

It would be nice though if reviewers took this into consideration though.
 
ChristianHass said:
Checking DxOMark it's not just Fuji.

The Olympus E-M5 is almost a full stop under it's stated ISO.

Camera ISO 200, DxO measured 107
Camera ISO 400, DxO measured 214
Camera ISO 800, DxO measured 394
Camera ISO 1600, DxO measured 782

The Nikon D7100 isn't quite as bad, but still quite a way off

Camera ISO 100, DxO measured 69
Camera ISO 200, DxO measured 138
Camera ISO 400, DxO measured 279
Camera ISO 800, DxO measured 552
Camera ISO 1600, DxO measured 1118

It would be nice with a clearly defined standard that everyone followed, but since ISO isn't as easily locked down as aperture and shutter speed it's probably not going to happen.

It would be nice though if reviewers took this into consideration though.
Click to expand...
 
MikeNannie said:
I started a thread recently on this topic here as well because I'm considering a move from Sony to Fuji and noise is one consideration. You might find it interesting.

http://www.dpreview.com/forums/thread/3646841

Related, and new, you might find Bill Fortney's comments of interest on his latest blog post.

http://billfortney.com/?p=10224

Be sure to read the comments.

Bill is a huge fan of Fuji and has decades of experience with Nikon, so I personally give his input a lot of credence. He calls the recent Popular Photography magazine's review of the XT-1 noise as hogwash.
Click to expand...
Thanks for linking that article on Bill Fortney's site. I love how he ended the article:
MikeNannie said:
Do I miss the Nikon system?

Sure, just like I miss my 30′s and 40′s!
Click to expand...
He misses Nikon, but, just like his lost youth, it's gone; got to move on with what works now.

Still, it would be nice for a someone to ask Fuji execs for an explanation of why they test the way they do vs. their competition.
 
I suppose there will always be people who make a big deal of this but it doesn't seem to make much difference to the people who actually own a Fuji or to the professional reviewers who highly recommend a Fuji.

Yes it is talked about, in some reviews, but doesn't seem to affect overall ratings.

Almost everyone knows Fuji's ISO ratings are not identical to some other cameras and Olympus has also been criticized, to some extent, for this.

Just the same, Fuji is very good at high ISO so whether you're taking a picture at ISO 6400 or, in reality, at ISO 5000 makes very little difference. They're just numbers and the end result is all that really matters.

All of this is old news and when I bought a Fuji X-E1 about a year and a half ago I knew about the ISO controversy. Didn't make much difference then and still doesn't; but I guess everyone is different and if a person is really concerned about the issue, they should definitely look at a different brand.
 
Last edited:
ChristianHass said:
Checking DxOMark it's not just Fuji.

The Olympus E-M5 is almost a full stop under it's stated ISO.

Camera ISO 200, DxO measured 107
Camera ISO 400, DxO measured 214
Camera ISO 800, DxO measured 394
Camera ISO 1600, DxO measured 782

The Nikon D7100 isn't quite as bad, but still quite a way off

Camera ISO 100, DxO measured 69
Camera ISO 200, DxO measured 138
Camera ISO 400, DxO measured 279
Camera ISO 800, DxO measured 552
Camera ISO 1600, DxO measured 1118

It would be nice with a clearly defined standard that everyone followed, but since ISO isn't as easily locked down as aperture and shutter speed it's probably not going to happen.

It would be nice though if reviewers took this into consideration though.
Click to expand...
 
deednets said:
I keep on reading this on various forums but can't quite follow where the reviewers come from here, e.g. the latest in the dpreview review of the X-T1 where it states that the 6400 is more like 4000 on other systems. When you hear this "other systems" you might be mistaken that Fuji cheats and the rest of the world doesn't.

4000 vs 6400 is substantial! However, when I tried to verify this for myself comparing files of a variety of cameras I had and have access to, I can never quite find the massive difference the reviewers seems to find. There was somebody here who used a couple of Sekonic light meters some time ago and found a difference but not as substantial as some reviewers think - and that the standard is not quite as carved in rock as it might sound, e.g. there is Fuji and then there is the honest rest.

An example? I just looked at the little D3 versus X-T1, 85mm on the D3 versus the 56 on the X-T1.

http://www.dpreview.com/forums/post/53495264

The D3 uses F8 and 1/60s @ ISO200, the Fuji uses F5.6 and 1/110s. When you click the 2 images at screen view, the D3 seems to be underexposed by more than the diference between 1/110s and 1/120s.

If the 2/3 stop difference was true (as in the example by dpreview of 4000 vs 6400) then I wonder what's going on with the example re the D3.

I am aware that the ISO curve might not be linear!

Any ideas as to why this will now be engraved for life that Fujis cheat, but I can't really follow? I must be a fanboy, right?? Or maybe the D3 is cheating, some here might remember that the D3 used to be another example for a high ISO capable camera ...

Deed
Click to expand...
this is not something that fujifilm has been doing since the beginning of digital cameras, it only started with the xpro1. The X100, X10, XS1, etc. expose similarly to the canon and NEX series. It's a little sad that Fuji (and Olympus) have gamed most internet review sites who don't account for this in their reviews, don't you agree? It was basically taken on faith that camera manufacturers would calibrate their ISOs similarly, and Fujifilm was following along with the industry until the introduction of X-trans.

Just look through DPreview image comparison database and look at the difference in exposure between X100, X10, and Xpro1, Xe1, etc. for the same test scene.
 
Last edited:
deednets said:
I keep on reading this on various forums but can't quite follow where the reviewers come from here, e.g. the latest in the dpreview review of the X-T1 where it states that the 6400 is more like 4000 on other systems. When you hear this "other systems" you might be mistaken that Fuji cheats and the rest of the world doesn't.

4000 vs 6400 is substantial! However, when I tried to verify this for myself comparing files of a variety of cameras I had and have access to, I can never quite find the massive difference the reviewers seems to find. There was somebody here who used a couple of Sekonic light meters some time ago and found a difference but not as substantial as some reviewers think - and that the standard is not quite as carved in rock as it might sound, e.g. there is Fuji and then there is the honest rest.

An example? I just looked at the little D3 versus X-T1, 85mm on the D3 versus the 56 on the X-T1.

http://www.dpreview.com/forums/post/53495264

The D3 uses F8 and 1/60s @ ISO200, the Fuji uses F5.6 and 1/110s. When you click the 2 images at screen view, the D3 seems to be underexposed by more than the diference between 1/110s and 1/120s.

If the 2/3 stop difference was true (as in the example by dpreview of 4000 vs 6400) then I wonder what's going on with the example re the D3.

I am aware that the ISO curve might not be linear!

Any ideas as to why this will now be engraved for life that Fujis cheat, but I can't really follow? I must be a fanboy, right?? Or maybe the D3 is cheating, some here might remember that the D3 used to be another example for a high ISO capable camera ...
Click to expand...
Yes, it's pretty well accepted that Fuji measures it's ISO differently, overstates, cheats, whatever you want to call it to the tune of between 1/2 to a full stop. At least with their x-Trans models. Does it matter? I'd say it matters a great deal when comparing cameras while considering a purchase and then not at all once you've bought one and are using it.

-Ray
--------------------------------------
We judge photographers by the photographs we see. We judge cameras by the photographs we miss - Haim Zamir
www.flickr.com

Ray

Explore Ray’s 2,013 photos on Flickr!
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Agreed. As look as the images look good I care less.
 
Regardless of how well it conforms to the standard, I personally like the rendering of noise at really high ISO.

Anyway, it's been said elsewhere that the ISO standard isn't as rigidly followed as people believe it is. Even in the film days there were films whose ISO rating was unofficially believed to be lower than stated.
 
DxOMark's measured ISO probably isn't what you think; it doesn't necessarily predict the shutter speed and aperture you need to get a specific image brightness at a given light level (although sometimes it might). It's used because DxOMark had to find a way around the slightly disconcerting fact that while they're specifically looking at RAW image quality, in reality RAW files don't really have an intrinsic ISO beyond what the photographer intended at the time of exposure.

DxOMark's measured ISO technically measures the sensor's clipping point. According to this definition, on any Fujifilm X-Trans camera ISO 100, ISO 200, ISO 400 DR200 and ISO 800 DR400 would all be considered to be exactly the same (and probably around ISO 125). I don't think many photographers would find this useful.

Because of this, those measurements you've listed can only really be used within the context of DxOMark's testing. They certainly can't be used to interpret our tests.
--
Andy Westlake
dpreview.com
 
deednets said:
I keep on reading this on various forums but can't quite follow where the reviewers come from here, e.g. the latest in the dpreview review of the X-T1 where it states that the 6400 is more like 4000 on other systems. When you hear this "other systems" you might be mistaken that Fuji cheats and the rest of the world doesn't.

4000 vs 6400 is substantial! However, when I tried to verify this for myself comparing files of a variety of cameras I had and have access to, I can never quite find the massive difference the reviewers seems to find. There was somebody here who used a couple of Sekonic light meters some time ago and found a difference but not as substantial as some reviewers think - and that the standard is not quite as carved in rock as it might sound, e.g. there is Fuji and then there is the honest rest.

An example? I just looked at the little D3 versus X-T1, 85mm on the D3 versus the 56 on the X-T1.

http://www.dpreview.com/forums/post/53495264

The D3 uses F8 and 1/60s @ ISO200, the Fuji uses F5.6 and 1/110s. When you click the 2 images at screen view, the D3 seems to be underexposed by more than the diference between 1/110s and 1/120s.

If the 2/3 stop difference was true (as in the example by dpreview of 4000 vs 6400) then I wonder what's going on with the example re the D3.

I am aware that the ISO curve might not be linear!

Any ideas as to why this will now be engraved for life that Fujis cheat, but I can't really follow? I must be a fanboy, right?? Or maybe the D3 is cheating, some here might remember that the D3 used to be another example for a high ISO capable camera ...

Deed
Click to expand...
It's really only an issue if you are comparative shooting. Otherwise, it just is what it is, and it's not a big deal.

People can make the biggest issue possible out of the most trivial things. This is one of those times.
 
ChristianHass said:
Checking DxOMark it's not just Fuji.

The Olympus E-M5 is almost a full stop under it's stated ISO.

Camera ISO 200, DxO measured 107
Camera ISO 400, DxO measured 214
Camera ISO 800, DxO measured 394
Camera ISO 1600, DxO measured 782

The Nikon D7100 isn't quite as bad, but still quite a way off

Camera ISO 100, DxO measured 69
Camera ISO 200, DxO measured 138
Camera ISO 400, DxO measured 279
Camera ISO 800, DxO measured 552
Camera ISO 1600, DxO measured 1118

It would be nice with a clearly defined standard that everyone followed, but since ISO isn't as easily locked down as aperture and shutter speed it's probably not going to happen.

It would be nice though if reviewers took this into consideration though.
Click to expand...
It's not the same thing as DPR's Andy Westlake explains here:

Loading…

www.dpreview.com
ChristianHass said:
DxOMark's 'measured ISO' is irrelevant to our tests In reply to Evan Effa, 5 hours ago

We already test the ISO rating of every camera we review. Fujifilm is indeed an outlier.

However, it's also extremely important to understand that DxOMark's 'Measured ISO' is something substantially different, that's really only important for how they choose to make their RAW image quality comparison. It's not what most photographers recognise as ISO, and it can't be used to interpret our tests. Instead, the difference between their measured and manufacturers' stated ISO is mainly to do with the highlight range above metered middle grey.

It's also worth noting that DxOMark hasn't tested any X-Trans CMOS cameras, because its methodology is more-or-less limited to comparing cameras with Bayer CFAs.
--
Andy Westlake
dpreview.com
Click to expand...
 
Sorry about this as it's essentially a dup post - just saw Andy's reply above and can no longer edit or withdraw the post.
 
When using the same shutter and aperture on both my Canon 5D MkIII and XT-1 the XT-1 renders an image thats's a half stop darker (so did my XE-1). In practical picture taking it doesn't really matter but if you are comparing how well these cameras handle noise at specific ISO speeds then you'd have to rate the XT-1 at a half stop lesser ISO to compare apples to apples..
 
gmanc said:
When using the same shutter and aperture on both my Canon 5D MkIII and XT-1 the XT-1 renders an image thats's a half stop darker (so did my XE-1). In practical picture taking it doesn't really matter but if you are comparing how well these cameras handle noise at specific ISO speeds then you'd have to rate the XT-1 at a half stop lesser ISO to compare apples to apples..
Click to expand...
As long as you are absolutely sure that shutter speeds and the lenses' f stops are comparable across the camera manufacturers. I'm pretty sure that 1/125s is never a 1/125s and f/1.4 is never a f/1.4, just like the iso values.

Regards
 
dengx said:
gmanc said:
When using the same shutter and aperture on both my Canon 5D MkIII and XT-1 the XT-1 renders an image thats's a half stop darker (so did my XE-1). In practical picture taking it doesn't really matter but if you are comparing how well these cameras handle noise at specific ISO speeds then you'd have to rate the XT-1 at a half stop lesser ISO to compare apples to apples..
Click to expand...
As long as you are absolutely sure that shutter speeds and the lenses' f stops are comparable across the camera manufacturers. I'm pretty sure that 1/125s is never a 1/125s and f/1.4 is never a f/1.4, just like the iso values.

Regards
Click to expand...
That's always been my thought on this issue. Who measures the shutter speed calibration used by different manufacturers and how do we know that some manufacturers aren't using say a 1/100 exposure time at a marked 1/125?

Saying that I think Fuji do probably measure ISO differently to some manufacturers and I don't care a jot!

Pat
 
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