• Members 549 posts
    April 27, 2023, 10:41 p.m.

    If the lighting is ambient, what do you vary in the camera to vary the photons?

  • Members 976 posts
    April 27, 2023, 10:43 p.m.

    Sensors are not rated in ISO units these days, what Jim lists as 1. & 2. are more of the noise counter-measures. I would say that in-camera JPEG engine and raw converters account for 1. & 2. when establishing default midtone brightness according to ISO standard (but ignoring that standard is not out of question too).

  • Members 727 posts
    April 27, 2023, 10:45 p.m.

    No problem. I cannot post any of these pictures since they are of kids.

  • Members 1738 posts
    April 27, 2023, 10:46 p.m.

    I can't argue with that. I was talking about gain introduced by the control labeled ISO, concentrating on the raw data and ignoring the details of the JPEG conversion.

  • Members 976 posts
    April 27, 2023, 10:50 p.m.

    I'm not arguing, Jim ;) I'm tying to say that this term, "ISO adjuster", may be misinterpreted.

  • Members 4254 posts
    April 27, 2023, 10:55 p.m.

    That can be true if you are limited to sooc jpegs.

    But is nonsense if anyone with limited skills in post processing tried to extrapolate that to mean it must apply to everyone.

    It is obviously possible to create on a computer stunning artistic versions of scenes that people will pay much more for than a sooc jpeg version.

  • Members 2365 posts
    April 27, 2023, 10:56 p.m.

    pretty much, but extended iso happens after the ADC from what ive read. I have also done some extensive reading into how valid the exposure triangle is today using digital cameras. and have come to the conclusion that there is absolutely nothing wrong with it. in fact there were never ever exposure meters in the days of film only light meters, the term exposure meters was born because the light meters had printed tables on them that you had to align. asa/iso had to be set as the default value before you could even read off shutter and aperture values. so to say that iso has no usable implementation even today is just plain silly.

  • Members 976 posts
    April 27, 2023, 11:05 p.m.

    Not always.

  • Members 2365 posts
    April 27, 2023, 11:09 p.m.

    I wish that was true, even when parents pay up to $4000 on dance lessons per year and $1000s of dollars on costumes that get worn for 10min, squeezing $10 for a 5x7 print is like extracting blood from a stone. but i work on mass sales 1000 images sold per school is why i keep doing it. work is work.

  • Members 4254 posts
    April 27, 2023, 11:14 p.m.

    Many people have accepted the same misconception but that is their choice to make.

    An example of the thing that the exposure triangle teaches that is wrong is it teaches that

    f/8, 1/400s, ISO 200

    and

    f/8, 1/200s, ISO 100

    are the same exposure - amount of light that struck the sensor per unit area while the shutter was open - when in fact they will output the same image lightness with the ISO 200 shot having received only half the exposure of the ISO 100 shot and so the ISO 200 shot will have more visible noise.

    Image lightness and exposure, although related, are two different things which the exposure triangle does not teach.

    With the exposure triangle you could argue that for a constant image lightness, not exposure as defined above, there is an inverse relationship between any two of aperture, shutter speed and iso.

    But I don't need a triangle or any other shape to understand that.

  • Members 4254 posts
    April 27, 2023, 11:23 p.m.

    I assume you are speaking on behalf of yourself.

    We could go in circles for hours on this and get nowhere.

    But having to sell 1000 photos and make less profit than a talented artist can make selling just a few pieces of digital art is a lot of extra work.

    Each to their own :-)

  • Removed user
    April 27, 2023, 11:31 p.m.

    Nobody will catch me arguing thus ... my argument has usually been that the ISO knob should be re-labeled "noise" or, if there's room, "degree of under-exposure", LOL.

  • Removed user
    April 27, 2023, 11:44 p.m.

    Good one, John ... !!

  • Members 4254 posts
    April 28, 2023, 1:06 a.m.

    That is because it wasn't the intention behind my op.

    For anyone needing advice/help on how to set exposure correctly with the aim to minimise visible noise then my post "Why are my photos noisy?" might help or at least steer you in the right direction.

  • Members 4254 posts
    April 28, 2023, 1:22 a.m.

    Of course it is ๐Ÿ™‚ Did you actually look at the title of my thread "The Exposure Triangle Is Misleading And Unnecessary."? ๐Ÿ˜Š

    In my op I explain why the exposure triangle is useless to me now and how I was mislead by its 'teachings' when I first got into photography. Now, whether anyone chooses to agree with me or not is their choice to make, hence the discussion in this thread.

    That's nonsense because in my very op I state very clearly what exposure* is and in most of my posts' signature I include what exposure* and optimal exposure** mean to me.

    All of that is described in my "Why are my photos noisy?" thread.

    * exposure - amount of light that struck the sensor per unit area while the shutter was open
    ** optimal exposure - the maximum exposure* within dof and motion blur requirements without clipping important highlights.
    *** under exposed - more exposure* could have been added with the DOF and blur constraints still being met without clipping important highlights.

  • Members 216 posts
    April 28, 2023, 4:09 a.m.

    When I use to shoot sporting mainly paintball events I always felt that I needed to upload that days work as soon as possible (most of the time it was 30min after the event). after about a year of doing this I looked at the log as to when the work was being downloaded I had 1 client that had done this 2 hours after the event in 1 year.
    After that I was in no real hurry and looked at getting things out within 24hrs.

    Even with sponsors 24 - 36 hours was about the earliest I uploaded and never had one sponsor logon 36 hours after the event in 12 years

  • Members 9 posts
    April 28, 2023, 6:46 a.m.

    Ignoring scene luminance, using the same aperture and exposure time yields the same exposure. ISO has no effect, whatsoever, on exposure.

    ISO can be implemented differently on digital cameras.

    • It can be implemented as an amplification of the pixel voltage before analogue digital conversion.
    • It can be implemented as change in analogue gain, by reducing the capacitance of the pixel.
    • It can simply be ignored and the data tagged to indicate 'ISO intent'

    Once the raw image is processed, ISO setting may affect processing, like increasing noise reduction.

    A large part of the noise in the image is coming from 'shot noise' which is random variation of light quanta reaching the pixels and that noise is only related to subject luminance and exposure.

    There are other sources of noise, but that noise mostly affects the darkest part of the image. ISO settings can have a significant effect on that noise.

    Best regards
    Erik

    Best regards
    Erik

  • Members 4254 posts
    April 28, 2023, 6:52 a.m.

    No, that is not correct at all because you cannot ignore the scene luminance when saying the same aperture and exposure time yields the same exposure*.

    Scene luminance along with aperture and shutter speed affect exposure*

    If you double the scene luminance while keeping aperture and shutter speed constant then you have doubled the exposure*, not kept it the same.

    * exposure - amount of light that struck the sensor per unit area while the shutter was open
    ** optimal exposure - the maximum exposure* within dof and motion blur requirements without clipping important highlights.
    *** under exposed - more exposure* could have been added with the DOF and blur constraints still being met without clipping important highlights.