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GX8 ISO100 DR ?

Discussion in 'Panasonic Cameras' started by Sootchucker, Aug 23, 2016.

  1. Sootchucker

    Sootchucker Mu-43 Regular

    116
    Aug 9, 2012
    I may have dreamt this, but I thought I read somewhere that the GX8 had been tested and found that the extended ISO of ISO100 had the same if not slightly more DR that at the native ISO200 ?

    Can anyone confirm or deny this and if not correct, does anyone know what sort of penalty we are looking at for using ISO100 please ?
     
  2. wjiang

    wjiang Mu-43 Hall of Famer

    • Informative Informative x 1
  3. Turbofrog

    Turbofrog Mu-43 Hall of Famer

    Mar 21, 2014
    Empirical testing seems to indicate that nearly all M4/3 cameras, with the exception of the E-M1, do in fact perform their best at their extended Low ISOs. Or at least equal to their nominal base ISO. Even in the case of the E-M1 it's a trivially small difference.

    Photographic Dynamic Range versus ISO Setting
     
    • Informative Informative x 1
  4. Sootchucker

    Sootchucker Mu-43 Regular

    116
    Aug 9, 2012
    Thanks guys. If that's the case, why has Panasonic made this an extended ISO and not a native one if it performs at worst as good as ISO 200, and at best slightly better ?
     
  5. eteless

    eteless Mu-43 All-Pro

    Jun 20, 2014
    Because that's exactly what it is, it loses a stop at the high end and gains a stop at the low end.
    In theory it should have no net change of DR however as dim detail is sometimes obscured by noise you can gain a very slight amount of DR. Given a normal daylit scene the high end is going to clip (rather than being a few values off to preserve data) and you will have a full range down into the low values.As it didn't save the very highest values and now has a complete range you "gain" a slight DR advantage, this is only really useful for graphs.

    In real world conditions I prefer using 200 rather than pulling as there's less chance of clipping, the theoretical gain of 0.x stops of DR is never noticed compared to the loss of highlight data if clipping occurs.
     
    • Appreciate Appreciate x 1
  6. vrds

    vrds Mu-43 Rookie

    15
    Apr 12, 2016
    With GX80/GX85 I don't anymore use extended ISO 100 (after one day of trying); too many shots with magenta/pink and also green problems in RAW when overexposed or brightness range is not limited and/or highlight has to be fixed.

    edit: added example photos
    Screenshot from 2016-08-24 13-12-05.png

    Screenshot from 2016-08-24 13-15-09.png
     
    Last edited: Aug 24, 2016
    • Informative Informative x 2
  7. Turbofrog

    Turbofrog Mu-43 Hall of Famer

    Mar 21, 2014
    Whoa, that's a real thing?! Did that involve heavy manipulation? Surely not the converted RAW straight out of camera?

    Geez. That looks like a highlight clipping warning...
     
  8. agentlossing

    agentlossing Mu-43 Hall of Famer

    Jun 26, 2013
    Andrew Lossing
    Yeah, that isn't out of camera color... Unless your camera is broken. Isn't that a highlight warning?

    Sent from my SAMSUNG-SM-N920A using Mu-43 app
     
  9. vrds

    vrds Mu-43 Rookie

    15
    Apr 12, 2016
    As far as I have understand the problem is caused by the Raw converter but this has happen with different Panasonic models and with different Raw developer software's when you use extended ISO 100; Lightroom, Darktable, RawTherapee, etc. Jpg looks always fine and with ISO 200 and higher there ain't any problems. But I have read that some converters work's fine with extended ISO. As an Linux user I'm stuck and I don't anymore use extended ISO. After some Google research I'm pretty sure that this is problem caused by software's, not by the camera.

    edit: Silkypix probably works. I have to try run it with Wine and see what happens. Still I think it is just more easy to use ISO 200 instead.
     
    Last edited: Aug 24, 2016
  10. eteless

    eteless Mu-43 All-Pro

    Jun 20, 2014
    This is part raw converter and part camera/sensor. What's happening is called Solarization, when the highlight is too high it's actually clips down to zero rather than stating a high number. Another good example of this is the black Sun effect (google "black sun camera" to get loads of examples, mainly with video).