• Members 137 posts
    May 4, 2023, 8:07 p.m.

    Which aren’t? While most sensors are more invariant beyond the dual-gain threshold overall, I would still consider them “largely” invariant (at least the ones I’m familiar with). If you require maximum DR, using an ISO setting below the dual-gain point in very low light can still be of great benefit.

  • Removed user
    May 4, 2023, 8:10 p.m.

    Sorry, I decline to answer the rhetorical questions.

    In your OP, you said that AFTER exposure settings are decided, the NEXT decision shall be about nominal ISO settings to dial in.

    now you argue that you decide about a nominal ISO EVEN BEFORE deciding about exact exposure parameters.

    I do hope that beginners will understand WHY these opposing statements were made ...

  • Members 457 posts
    May 4, 2023, 8:12 p.m.

    Pentax K-3 III and Pentax K-1 II:
    www.photonstophotos.net/Charts/RN_e.htm#Pentax%20K-1%20II_14,Pentax%20K-3%20III_14

  • Members 260 posts
    May 4, 2023, 8:13 p.m.

    they are either invariant or not - and in practical terms dual gain sensors sufficiently not invariant - unless you start to narrow things down to : oh,yes - between these 2 nominal settings ISO1600 and ISO3200 they are, thus excluding away parts that not suit you ... come on

  • Members 1737 posts
    May 4, 2023, 8:18 p.m.

    You are correct. the radical got lost in translation. I've notified Lensrentals.

    Thanks.

    image.png

    image.png

    PNG, 14.2 KB, uploaded by JimKasson on May 4, 2023.

  • May 4, 2023, 8:19 p.m.
    1. I am onkly interested in the raw file.

    2. I set aperture and exposure.

    3. I then have to set ISO. But how do I determine the optimum value for this?

    David

  • Members 1737 posts
    May 4, 2023, 8:20 p.m.

    The Lensrentals folks left out the radical. Here's what it is supposed to look like:

    image.png

    I've notified them and hopefully they'll fix it soon.

    image.png

    PNG, 14.2 KB, uploaded by JimKasson on May 4, 2023.

  • May 4, 2023, 8:23 p.m.

    JIm,

    In the wikipedia definition of exposure, near the beginning of your article, there must be an "of" missing in the first line (amount of light).

    David

  • Members 260 posts
    May 4, 2023, 8:23 p.m.

    you check BClaff site for a start (unless you can DIY the same) and then you test yourself though raw conversion - because graphs might still lie to you apparently ( see @IliahBorg about R5)

  • Members 1737 posts
    May 4, 2023, 8:27 p.m.

    Thanks. I've asked them to make the change.

  • Members 1737 posts
    May 4, 2023, 8:30 p.m.

    Set it at base ISO with an ETTR exposure if you can.

    If you want to lower read noise, have a brighter finder image, or avoid extreme pushes in your raw developer, raise it a bit, but don't get greedy and run the risk of highlight clipping. The details depend on your camera.

  • Members 260 posts
    May 4, 2023, 8:32 p.m.

    they are not opposing

    in an ideal scenario, when I have time/etc, I will decide AFTER ... but in a practical case I do decide BEFORE ( because I might not have time to decide precisely - so for example I select a certain Auto ISO before I start using M mode ) ... ISO not part of exposure ( process, from when exposure of a photo-site/sensel starts till that exposure ends ), but knowing how it affects the raw files (and raw processing using your specific raw converter and not abstract ideal something) becoming a part of your decision about exposure parameters to dial in ( aperture, exposure time and if you control the light, like strobes/etc - that too ) ... in that sense "ISO" still hangs around "exposure"

  • Members 1737 posts
    May 4, 2023, 8:41 p.m.

    I don't' use auto ISO, but in the past seven or eight years I have not been in a situation where I picked my exposure based on the ISO setting I wanted to use.

  • Members 260 posts
    May 4, 2023, 8:56 p.m.

    I use Auto ISO and I select it once before moving to shot in M mode during some party time where I am also a part of that fun ( because I rather not fond of selecting like 2nd base ISO and pushing in raw converter or something along the lines ) - in that sense I am picking my exposure AFTER I decided about a nominal ISO ( that is I set limits for a camera to assist me and decide about the exact nominal ISO value within said limits understanding that it might not be all ideal and yes I might adjust some exposure parameters - but not auto ISO limits because that is way suits me - with what I like to do later w/ raw files in raw conversion ) - does not mean "based" on it the sense I feel you want to put in it

    and if I move to use a strobe in middle because my friends want to have some posed photos under a good light then I do decide to use either a 1st base ISO or 2nd base ISO and that's it.... I will change aperture ( to get more or less people/faces/etc in DOF ), but not ISO - that I decide before based on the idea how much illumination I can deliver, etc ... so I do not change a nominal ISO after adjusting aperture/power output etc ... it is practical situation... does not matter that I agree w/ all ISO not part of exposure - it is just the way it goes in the real life

  • Members 2332 posts
    May 4, 2023, 9:01 p.m.

    who said they havnt ? all cameras histograms are calibrated on the safe side of clipping thats all. plug a field monitor into your camera and see what a very detailed histogram looks like compared to say raw digger. on my sony a74 you can calibrate the cameras metering system and also the histogram/blinkies clipping warnings. been there done that and reset the camera back to default settings for 1/3 stop head room.

  • Members 976 posts
    May 4, 2023, 9:11 p.m.
  • Members 217 posts
    May 4, 2023, 9:12 p.m.

    Because they haven't.

  • Members 1737 posts
    May 4, 2023, 9:18 p.m.

    Let me go on record as saying that the statements above don't reflect any of what I have learned in more than a decade of serious, quantitative camera testing. This continued tooting of the horn of misinformation is tiresome.

    Modern cameras are in some ways so forgiving that you can do things that are far from optimal and still get good images.