Fuji's ISOless sensor

Discussion in 'Coffee with Rico Pfirstinger, Fuji X-Pert' started by flysurfer, Feb 26, 2014.

  1. flysurfer

    flysurfer X-Pert

    Feb 1, 2013
    Nuremberg
    Rico Pfirstinger
    As you may know, Fuji's APS-C cameras are using sensors that are actually made at Sony (Fuji of course disputes this, which is quite laughable) using Sony's "ISOless" sensor design. This modern design means that ISO settings are becoming more and more irrelevant. Instead, exposure can be digitally pushed or pulled at will during the subsequent RAW conversion. You basically expose your image "after the fact". All you have to do is set base ISO and whatever aperture and shutter speed you want or need. Just make sure not to overexpose the shot.

    Sadly, current RAW aren't equipped to fully support this feature. If they did, we could basically shoot everything in ISO 200 and then push our exposure later to whatever brightness level wie require. Even an ISO 6400 image could just be an ISO 200 image that is pushed 5 stops in Lightroom, Aperture, Silkypix, Capture One or in the camera's internal RAW converter.

    Now, to be fair, there's still some analog amplification going on at lower ISO levels, typically between base ISO and ISO 800 or 1600 (depending on the sensor's calibration). However, the quality difference between a digital push and analog/digital hybrid amplification is very small.

    Don't believe me?

    Well, here's a little test for you. I am showing you two images, both shot with an X-E2 at ISO 800 with identical exposure parameters (f/9, 1/30s) from a tripod with self-timer:

    12792559405_2d940aa7a7.

    12792930154_e4a1dd08e0.

    Both images then received identical processing in Adobe Lightroom 5.3.

    So what's the difference here?

    One RAW image was shot at DR100%, one at DR400%. We know that DR100% results in a "genuine" ISO 800 RAW file (with analog/digital hybrid amplification), whereas the DR400% shot results in an "underexposed" ISO 200 RAW that has to be digitally pushed 2 stops in the RAW converter. Lightroom automatically takes care of this push once it recognizes the DR400% marker in the shot's EXIF metadata (Fuji Maker Notes).

    So while one image was shot conventionally, the other on was processed ISOless using the RAW converter. The conventional shot becomes ISO 800 through analog/digital in-camera signal amplification, the ISOless RAW is an ISO 200 RAW that becomes ISO 800 by digitally pushing it 2 stops in Lightroom.

    I won't tell you which image is which, and I challenge you to find out for yourself by pixel peeping at the full-size versions. Just click on the two images to open large 18 MB JPEGs at 100% magnification.
     
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  2. BBW

    BBW Super Moderator Subscribing Member

    Feb 8, 2013
    NW corner of CT
    BB
    I give up! Maybe if I stared long enough and hard enough?

    Very interesting to know, Rico.
     
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  3. CaptZoom

    CaptZoom FujiXspot Regular

    166
    Mar 22, 2013
    A couple of years ago, some photographers discovered pushing ISO in post resulted in better image quality versus setting a higher ISO at capture on the M9. Subsequently, it was proven that there exists a point after which pushing ISO in post results better image quality; staying below the point, in-camera ISO push is better. Up to 640, the camera does a better job of pushing ISO; after 640, software does better. So the idea is set the maximum ISO to 640, and thereafter use the camera as ISO-less.*
    Any ISO setting other than the sensors base ISO is software driven gain. At some ISOs the cameras firmware does a better job than post processing software. I wonder why camera manufacturers and 3rd party software developers don't work more closely to address this together.

    * Specific to the M9. Other cameras have different cross over points, more about this in Rico's post below.
     
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  4. flysurfer

    flysurfer X-Pert

    Feb 1, 2013
    Nuremberg
    Rico Pfirstinger
    The ISOless performance is also the reason why DR expansion works so well in Fuji cameras (and others using similar sensors). There's virtually no quality difference between a normal (aka DR100%) ISO 800 shot and an ISO 800 shot with 2 stops of additional highlight DR. At even higher ISOs (like ISO 3200 or 6400), there's absolutely no difference at all, because the push is digital in any case.

    As you know from another thread of mine, Fuji's APS-C cameras record RAW file data with a maximum of ISO 1600. Anything beyond that is digitally pushed up during RAW conversion. Since external RAW converters don't support a proper digital push beyond 2 EV, extended ISO (12800, 25600 etc.) is restricted to JPEG-only in Fujiland. There's simply no way Lightroom, Silkypix etc. would automatically push the ISO 1600 RAW file 3 or 4 stops on import (or even 5 stops in the X-T1 with its new ISO 51200 setting). Quality would suffer, too, because the camera can apply custom processing and noise reduction that standard third-party converters would be lacking, as they aren't that perfectly calibrated for a specific camera model. Most RAW converter makers don't receive any support from camera makers, they have to reverse-engineer everything based on RAW files that they receive from guys like me.
     
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  5. Daniel Sullivan

    Daniel Sullivan FujiXspot Rookie

    21
    Feb 10, 2014
    I'm sorry if this is the wrong place to ask, but I'm wondering about interior architecture shots. I usually opt for the low ISO + extremely slow shutter speed which requires using a tripod. Could I, theoretically, go for a higher ISO and faster shutter, then push the exposure without degrading effects?
     
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  6. CaptZoom

    CaptZoom FujiXspot Regular

    166
    Mar 22, 2013
    An unfortunate reality.
     
  7. CaptZoom

    CaptZoom FujiXspot Regular

    166
    Mar 22, 2013
    Short answer is yes, especially for ISO above 1600 (thanks Rico). Experiment at home, and verify it for yourself.
     
  8. flysurfer

    flysurfer X-Pert

    Feb 1, 2013
    Nuremberg
    Rico Pfirstinger
    ISO 1600, 3200 and 6400 results will not look as great as ISO 200 shots taken from a tripod. So I certainly recommend low ISO for stationary scenes.

    ISOless means that there isn't much of a difference between analog and digital signal amplification / push. It doesn't mean that ISO 6400 is just as good as ISO 200. Base ISO will always lead to optimal results, if you can somehow manage to expose correctly using it.
     
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  9. CaptZoom

    CaptZoom FujiXspot Regular

    166
    Mar 22, 2013
    I know...but he wants to hand hold the shots where using the base ISO requires shutter speeds that are too long.
    -----------
    Edit- My mistake. He never mentioned hand holding.
     
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  10. Armanius

    Armanius FujiXspot Top Veteran

    691
    Feb 1, 2013
    Texas
    Muttley
    Reading this is giving me a headache ... definitely above my pay grade. :) I just want to see ISO 6400 photos that don't lose any detail (when compared to ISO 200) and are noise free!!
     
  11. flysurfer

    flysurfer X-Pert

    Feb 1, 2013
    Nuremberg
    Rico Pfirstinger
    So do I.
     
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  12. Ray Sachs

    Ray Sachs FujiXspot Veteran

    485
    Feb 1, 2013
    Near Philadephila
    Not to go too far down this road again, but you should check out a Df.....:cool:

    -Ray
     
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  13. Armanius

    Armanius FujiXspot Top Veteran

    691
    Feb 1, 2013
    Texas
    Muttley
    I feel like you are cyberstalking me today!

    I came an inch from buying a Df, before I bought the A7, right before the Europe trip.
     
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  14. pniev

    pniev FujiXspot Veteran

    489
    May 13, 2013
    Or wait for the organic sensor. Hopefully next year. ;-)

     
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  15. pniev

    pniev FujiXspot Veteran

    489
    May 13, 2013
    Congrats with the A7 (and the trip).
     
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  16. flysurfer

    flysurfer X-Pert

    Feb 1, 2013
    Nuremberg
    Rico Pfirstinger
    Maybe next decade.
     
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  17. snkenai

    snkenai FujiXspot Regular

    57
    Jan 31, 2013
    Campbellsville, KY
    Almost

    Almost, you guys pursuade me to go Fuji ( the almost, is lack of extra funds :eek:). But the most of you cannot seem, to quite let go completely, of the m4/3 format. So, maybe I'm not too handicapped, by my puny sensors. It's only that humans (me), are never completely satisfied with what we have. Watch small children, in a play room, with lots of toys. If you are enjoying yours, it must be better than the one I have. So, I want yours. And when I get it, I look and you have a different one, that you are having more fun, than I am. How did that happen? :confused:

    So, I think I'll take my toy, and go out and play today. That way, I won't be drooling, over all your "different" ones, than I have. I find that the best satisfaction, comes from the really nice images that I get, when I actually go for what I see around me, that is a joy to the senses, like the sunset last night. Only had time to grab the camera, and trigger off a couple shots, and it was gone.

    Did not see the black birds, until I uploaded to the computer.

    [​IMG]
     
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  18. CaptZoom

    CaptZoom FujiXspot Regular

    166
    Mar 22, 2013
    Didn't a Fuji rep recently say they were waiting for a "break through" before releasing the follow up to the X-Pro 1, and to look for it around 2015? I assumed he was referring to the organic sensor, but as usual "break through" can refer to any number of things.

    -------
    [mention=23945]snkenai[/mention]
    Nice pic.
    The m4/3 sensor isn't much smaller than APS-C sensors. The significantly different aspect ratio makes linear comparisons difficult even though there is a direct relationship between the covered areas.
     
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  19. pniev

    pniev FujiXspot Veteran

    489
    May 13, 2013
    That was my interpretation as well, especially after reading a few articles about the status of the Fuji and Panasonic partnership. It was my understanding that they do have working prototypes. The big question/challenge is to produce a sufficient number of reliable and affordable sensors. So my best guess is (pardon me, was) that Fuji would first try to produce an organic-sensor based x-pro2. My interpretation of their remark that they do not rule out a full-frame sensor was that a full-frame sensor based x-pro2 would only be considered if the organic sensor does not turn out to be a viable and profitable option. To me, a fullframe Fuji does not make much sense because the existing and coming lenses are APS-C only (to my knowledge).

    But, as you rightfully say, breakthrough can refer to many things.

    I am sure Rico is much better equipped to interpret what's going on! It makes me reluctant to invest in more Fuji glass right now. The X-T1 manual focus support is excellent, so 1 or 2 Leica lenses is another option.

    Peter


     
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  20. jloden

    jloden FujiXspot Top Veteran

    708
    Mar 9, 2013
    Hunterdon County, NJ
    Jay
    Rico, this is really interesting, thanks for sharing it.

    Do you know if this is this a Fuji-only sensor technology or does this show up in other cameras as well?