• Members 976 posts
    April 24, 2023, 11:12 a.m.

    Irrelevant. By definition, exposure value (EV) in photography is a number that combines aperture and shutter speed.

    I'm asking about the on-camera user control over ISO, "is it possible to design a camera without an ISO dial?" The answer is "yes". In fact, there are cameras where the ISO dial does nothing, absolutely nothing, to raw data.

    Car analogies are lame.

    Instead, answer this:

  • Foundation 177 posts
    April 24, 2023, 11:28 a.m.

    True, but the steering system has nothing to do with controlling speed

    Similarly, ISO has nothing to do with controlling exposure

    Tim

  • Members 2322 posts
    April 24, 2023, 11:29 a.m.

    EV has been around for 100 years when light meters were invented. "exposure" and "exposure value" have 2 different meanings.
    skylum.com/blog/what-is-exposure-value
    www.earlyphotography.co.uk/site/meters.html
    www.youtube.com/watch?v=ouziW7mnWAs&t=4s

  • Members 976 posts
    April 24, 2023, 11:51 a.m.

    Wrong. Less than 70. I leave it to you to calculate your error in %.

    History of light meters starts in 1843.

    But you referred to exposure value:

    So, the below stays, no ISO in exposure value:

    You are trying to avoid giving correct answers that you surely know - is it because they undermine your writings?

  • Members 2322 posts
    April 24, 2023, 11:53 a.m.

    as i have already said your going to have a hard time justerfying your meaning
    my new a74 menu in fact every camera i have owned says the same.
    P1016694.JPG

    P1016704.JPG

    P1016704.JPG

    JPG, 1.1 MB, uploaded by DonaldB on April 24, 2023.

    P1016694.JPG

    JPG, 1.2 MB, uploaded by DonaldB on April 24, 2023.

  • Members 976 posts
    April 24, 2023, 12:09 p.m.

    To you, maybe.

  • Members 4193 posts
    April 25, 2023, 1:02 a.m.

    If your goal is a nice looking sooc jpeg then yes, that is true.

    If you are shooting raw and your goal is to maximise the quality of the raw data then that is not true as has been explained many times in numerous posts in several threads. You can maximise the exposure* in order to maximise the quality of the raw data and still let the camera set ISO wherever it likes as long as important highlights are not clipped and you then set the final image lightness in post.

    * 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 2322 posts
    April 25, 2023, 1:35 a.m.

    Light meters from 70 years ago article.

    Direct reading. The simplest arrangement is for the needle to move over a scale of shutter speeds and indicate directly which value to use. This would be correct for one film speed and aperture, for other values a set of printed tables would be used.
    another type.
    www.youtube.com/watch?v=TD1cmBqT9B4&t=2s

  • Members 4193 posts
    April 25, 2023, 2:40 a.m.

    I posted earlier I don't need a light meter to maximise my exposure* for the shot.

    A light meter is not going to tell me the minimum shutter speed I need to satisfy my motion blur requirements or the widest aperture I can use to meet my dof requirements.

    Obviously light meters can be helpful for some photographers, not for me though.

  • Members 538 posts
    April 25, 2023, 1:17 p.m.

    That is the kind of thing that you might do if you are giving up the film to a deterministic or default processing from development through printing. That is not what photography requires you to do, with digital cameras, especially those with raw capture, and even with film, you may have some degree of freedom of development of film and prints.

    You can ride the Exposure Tricycle if you like, but it may not be necessary or ideal.

  • Members 538 posts
    April 25, 2023, 1:32 p.m.

    I remember the first time I downloaded a Sigma SD9 raw file. It was marked ISO 800 in the metadata, and when I looked at the raw values I just assumed that because it looked about 3 stops shy of my Canon raws in a raw histogram that it was actually 3 stops higher than 800, or about 6400 for the actual ISO exposure index. So, I wondered why everyone was saying that the SD9 had so much chromatic noise, because this "ISO 6400" actually looked pretty good. I had no idea at the time that for this camera, there was no variable gain; neither analog nor mathematical; the ISO setting just changed some non-image numbers in the metadata.

  • Members 2322 posts
    April 26, 2023, 6:51 a.m.

    its call a cell phone :-) 😁 I control my studio lighting with iso with fixed shutter + aperture.
    seriously a quad gain sensor is my pick (4 step fixed iso control). whats a couple more components over dual gain.

  • Members 976 posts
    April 26, 2023, 9:17 a.m.

    You've chosen to talk nonsense.

  • Members 2322 posts
    April 26, 2023, 10:55 a.m.

    what camera has the lowest noise at iso 100 pushed 5 stops or iso 4000 between the sony a6300 or the sony a74 apsc mode ?

    an image taken at iso 100 pushed 5 stops have higher or lower noise than an image taken at iso 4000 either camera.