you are on the new server domainname will switch later
If you can not login please clear cookies
chevron_left
chevron_right
The-Photo forum
  • Home
  • Forums
    • theatersImage Discussions arrow_forward
      • chat_bubbleChallenges arrow_forward
        • camera Edit me an Image
        • camera Photo of the Week
      • chat_bubbleHave your photos Critiqued arrow_forward
        • camera Wednesday C&C
      • Showcase your Photos
      • chat_bubbleWeekly & Topic Image Threads arrow_forward
        • camera Abstract/Experimental
        • camera B&W Threads
        • camera Sunday Cats!
        • camera Weekly Collegial forum
        • camera Daily Outing
        • camera This week through your eyes
        • camera Landscape
        • camera Street Photography
    • theatersMiscellaneous forums arrow_forward
      • Photo Hardware Discussions
      • Industry News
    • theatersOther Photography Talk arrow_forward
      • General Articles
      • Photo History Trivia
      • Open discussions
      • Technical Discussions
    • theatersSite Discussions arrow_forward
      • Governance and organisation
      • Updates & Bugs
    • theatersWelcome arrow_forward
      • chat_bubbleForum Guidelines arrow_forward
        • camera Misplaced Posts
      • Introduce yourself
  • Threads
  • Users
  • Web Site
  • message
  • group
  • chevron_right Threads
  • label Other Other Photography Talk
  • label Open Open discussions

A new exposure triangle for raw shooters

JimKasson
June 11, 2023
chat_bubble_outline 41
arrow_downward chevron_right last_page
  • link
    JimKasson
    Members 1738 posts
    June 11, 2023, 5:16 p.m. June 11, 2023, 5:16 p.m.
    link

    Here's a graphic that displays the light levels recordable at various ISOs in a camera with a base ISO of 100. It ignores read noise.

    image.png

    Comments?

    image.png

    PNG, 37.5 KB, uploaded by JimKasson on June 11, 2023.

    bastibe, pwilly, Hoppy and 3 other users like this.

    favorite 6

  • link
    finnan
    Members 322 posts
    June 11, 2023, 8:16 p.m. June 11, 2023, 8:16 p.m.
    link

    HAND.

    CrashpcCZ likes this.

    favorite 1

  • link
    JimKasson
    Members 1738 posts
    June 11, 2023, 9:46 p.m. June 11, 2023, 9:46 p.m.
    link
    @finnan has written:

    Seems somewhat plausible for a camera / sensor with an ~12 bit linear ADC.

    Or 13, 14, or 16 bits of precision.

    @finnan has written:

    However, I don't see how it accounts for model specific highlight headroom.

    That's a myth, measured with respect to full scale. I've only tested one camera with significant highlight nonlinearity before clipping, and that camera only did it at one ISO setting. I think the myth got started because of the different ways that camera's metering systems are set up.

    @finnan has written:

    And afaik there exist cameras / sensors with various bit depths, even dual output gain designs (e.g. Arri, Panasonic).

    As I said in the OP, I'm ignoring read noise here. And precision doesn't play a part in this graphic if the ADC precision is12 bits or more, so I'm not understanding what you're getting at here.

  • link
    SrMi
    Members 457 posts
    June 11, 2023, 9:54 p.m. June 11, 2023, 9:54 p.m.
    link
    @JimKasson has written:

    That's a myth, measured with respect to full scale. I've only tested one camera with significant highlight nonlinearity before clipping, and that camera only did it at one ISO setting. I think the myth got started because of the different ways that camera's metering systems are set up

    I wonder if that myth was started by including highlight reconstruction, i.e., the camera’s behavior after clipping of at least one channel. I have observed different amount of highlight reconstruction potential with different cameras (Leica M), but have not looked into it in more details. Highlight recovery is a game of luck as one never knows whether color will be preserved or not. Nonetheless, it is very helpful when exposing incorrectly.

  • link
    JimKasson
    Members 1738 posts
    June 11, 2023, 10:27 p.m. June 11, 2023, 10:27 p.m.
    link
    @SrMi has written:

    I wonder if that myth was started by including highlight reconstruction, i.e., the camera’s behavior after clipping of at least one channel.

    As I understand it, highlight reconstruction is affected in the camera design mainly by the compromise matrix, and thus the CFA. But highlight reconstruction is not performed in camera, but by the raw developer.

    SrMi likes this.

    favorite 1

  • link
    IliahBorg
    Members 976 posts
    June 11, 2023, 10:43 p.m. June 11, 2023, 10:43 p.m.
    link
    @finnan has written:

    model specific highlight headroom

    Does photo diode-specific highlight headroom make sense?

  • link
    Deleted Removed user
    June 12, 2023, 1:29 a.m. June 12, 2023, 1:29 a.m.
    link
    @IliahBorg has written:
    @finnan has written:

    model specific highlight headroom

    Does photo diode-specific highlight headroom make sense?

    Maybe ...

    kronometric.org/phot/sensor/diodeSat.gif

    JohnMoyer likes this.

    favorite 1

  • link
    IliahBorg
    Members 976 posts
    June 12, 2023, 2:24 a.m. June 12, 2023, 2:24 a.m.
    link
    @xpatUSA has written:
    @IliahBorg has written:
    @finnan has written:

    model specific highlight headroom

    Does photo diode-specific highlight headroom make sense?

    Maybe ...

    kronometric.org/phot/sensor/diodeSat.gif

    Shoulder is what I see ;)
    Even more interesting in photo-voltaic mode (used in some technical sensor applications, I use one of those to shoot welding).

    JohnMoyer likes this.

    favorite 1

  • link
    SrMi
    Members 457 posts
    June 12, 2023, 5:22 a.m. June 12, 2023, 5:22 a.m.
    link
    @JimKasson has written:
    @SrMi has written:

    I wonder if that myth was started by including highlight reconstruction, i.e., the camera’s behavior after clipping of at least one channel.

    As I understand it, highlight reconstruction is affected in the camera design mainly by the compromise matrix, and thus the CFA. But highlight reconstruction is not performed in camera, but by the raw developer.

    Any highlight headroom comparison and analysis that I have seen, evaluated how clipped raw files are handled by raw developer :(.

  • link
    finnan
    Members 322 posts
    June 12, 2023, 6:19 a.m. June 12, 2023, 6:19 a.m.
    link

    HAND.

  • link
    SrMi
    Members 457 posts
    June 12, 2023, 6:59 a.m. June 12, 2023, 6:59 a.m.
    link
    @finnan has written:

    Sorry, I just don't buy that.

    Can you elaborate? Jim's graphic is not related to DR, as I understand it.

  • link
    finnan
    Members 322 posts
    June 12, 2023, 7:26 a.m. June 12, 2023, 7:26 a.m.
    link

    HAND.

  • link
    JimKasson
    Members 1738 posts
    June 12, 2023, 3:45 p.m. June 12, 2023, 3:45 p.m.
    link
    @xpatUSA has written:
    @IliahBorg has written:
    @finnan has written:

    model specific highlight headroom

    Does photo diode-specific highlight headroom make sense?

    Maybe ...

    kronometric.org/phot/sensor/diodeSat.gif

    With one exception at one ISO setting, all the cameras I've tested are designed so that the ADC clips before the curve above bends over far enough to be photographically useful.

    IliahBorg and SrMi like this.

    favorite 2

  • link
    JimKasson
    Members 1738 posts
    June 12, 2023, 3:48 p.m. June 12, 2023, 3:48 p.m.
    link
    @finnan has written:
    @SrMi has written:
    @finnan has written:

    Sorry, I just don't buy that.

    Can you elaborate? Jim's graphic is not related to DR, as I understand it.

    Maybe I simple have no idea what Jim refers to when he says "light levels recordable at various ISOs" in the OP.
    Not related to DR? D'oh!

    In order to relate the graphic to DR, I'd have to bring in read noise and photon noise, and also pick a SNR threshold. That would make it camera specific. I didn't want to do that. DR is full scale over mean at some threshold SNR, so you can't read DR off the graphic. What the graphic does show is the effect of ISO setting on full scale with full scale measured in lux-seconds of exposure.

    For camera-specific DR vs ISO curves, see Bill Claff's PDR charts.

    JackHogan likes this.

    favorite 1

  • link
    IliahBorg
    Members 976 posts
    June 12, 2023, 3:59 p.m. June 12, 2023, 3:59 p.m.
    link
    @JimKasson has written:

    With one exception at one ISO setting, all the cameras I've tested are designed so that the ADC clips before the curve above bends over far enough to be photographically useful.

    Same here.

    JimKasson likes this.

    favorite 1

  • link
    finnan
    Members 322 posts
    June 12, 2023, 6:23 p.m. June 12, 2023, 6:23 p.m.
    link

    HAND.

    JohnMoyer likes this.

    favorite 1

  • link
    IliahBorg
    Members 976 posts
    June 12, 2023, 6:38 p.m. June 12, 2023, 6:38 p.m.
    link
    @finnan has written:

    Why stop at 11?

    "above arbitrary base".

    JimKasson likes this.

    favorite 1

  • link
    finnan
    Members 322 posts
    June 12, 2023, 9:12 p.m. June 12, 2023, 9:12 p.m.
    link

    HAND.

arrow_upward chevron_right last_page

There are 24 more posts in this thread.

  • DPRevived.com & the-photo.org are owned and operated by The Photographer's Foundation Limited, registered in England, company number 14795583. Contact us here https://the-photo.org/contact.html
powered by misago