• Members 3973 posts
    April 10, 2023, 9:23 p.m.

    I think most would agree with my op.

  • Members 244 posts
    April 10, 2023, 9:29 p.m.

    “Most” is a majority. Perhaps you are correct.
    I think that some portion of working, notable, published pros would neither agree or disagree because they couldn’t care less. They just need to make good/great images and do so regardless of “classroom perfection”.

  • Members 2310 posts
    April 10, 2023, 9:32 p.m.

    i was only reaving the guy up 😎

  • Members 976 posts
    April 10, 2023, 9:32 p.m.

    I never said underexposure is always avoidable.

  • Members 142 posts
    April 10, 2023, 9:36 p.m.

    You maximized your exposure to match your dof and motion blur requirements. You also adjusted the camera's ISO setting to lighten the picture to acceptable levels. Beyond the definition of exposure, I don't see the disagreement.

    "exposure - amount of light striking the sensor per unit area while the shutter is 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 2310 posts
    April 10, 2023, 9:41 p.m.

    what if id used silent shutter, well we better not call it shutter as its not technically correct . what should we call it ? and the sensor is always exposed 🙄

  • Members 3973 posts
    April 10, 2023, 9:47 p.m.

    On my camera it's called LiveView but I don't see how that is related to my op.

  • Members 2310 posts
    April 10, 2023, 9:50 p.m.
  • Members 3973 posts
    April 10, 2023, 9:51 p.m.

    I see it as another example where you got it wrong and are trying to cover it up again :-)

  • April 10, 2023, 9:52 p.m.

    While this discussion is wonderful (and in the interests of harmony, I agree with every post 😂), I think you have to go back to where we are - we are in a "Beginners Questions" Discussion.

    To a beginner, generally someone who has picked up their first digital camera, there IS a relationship between speed, exposure and ISO. He or she will double the speed, halve the ISO and get a picture which looks the same on their 5 year old iPad. They won't care that there might be more or less noise - or they can turn down EC and then change it in post processing.They see "I can turn ISO up which means I can take better pictures in low light".

    I think we have gone way beyond a "Beginners Discussion" here. Not to say we should stop discussing - far from it - but let the beginner know that there IS a relationship, there is an exposure triangle - for THEM. Because it works. For THEM.

    Alan
    [Just putting the fox in the hen house to see what happens 😁😁]

  • Members 3973 posts
    April 10, 2023, 9:52 p.m.
  • Members 3973 posts
    April 10, 2023, 9:57 p.m.

    I did all that in my op. I explained what the relationship between aperture, shutter speed and iso actually is and what it actually isn't and so far no-one has posted anything that shows what I posted is not accurate.

  • Members 142 posts
    April 10, 2023, 9:58 p.m.

    You've done it properly for so long that I suspect you've forgotten how difficult it is for beginners to separate their thinking into two steps:
    ...Adjust the shutter and aperture as needed to handle motion blur and depth of field
    ...Adjust the ISO to achieve desired image brightness

    I'm sure you've seen beginners walk around with their cameras set to high ISO in bright daylight wondering why their pictures are so noisy.
    Separating the decision process into two steps (and avoiding the "triangle") is meant to help them avoid that problem.

    Sherm

  • Members 244 posts
    April 10, 2023, 10:03 p.m.

    What matters to beginners and, IMO, working pros is simply this: “did I capture the image that I wanted/will this satisfy the client/will this sell?” Highly technical discussions, IMO, often don’t help the beginner and the folks making money off of their photography simply don’t care.

  • Members 3973 posts
    April 10, 2023, 10:03 p.m.

    I don't know where that image actually came from, what settings were actually used or what post processing might have been applied to it, and so has nothing to do with my op.

  • Members 318 posts
    April 10, 2023, 10:16 p.m.

    The misconceptions that are thrown out - I am sure to help - but cause more confusion (and food fights on Internet forums today the exposure triangle is number one. It doesn't exist. Exposure has a physical definition. It is the amount of optical energy incident on a sensor - no more and no less. It doesn't matter if the sensor is film or silicon. It can be calculated by the it is the radiant flux received by the surface times the time of exposure ( in our case shutter speed). The units are given in J-sec/m^2. ISO - does not enter into any of these equations.

    The second concept of importance is sensor sensitivity. Be it film, it is the amount of exposure required so that the results under calibrated development results in a detect predefined density. For digital it is the same as the definition for sensitivity of an optical sensor - the energy required to generate the minimal detectable signal. These are functions of the film and the digital sensor - largely determined by the materials, designs and semiconductor process used to generate the photodetectors on the sensor.

    In the film days - the term ISO was falsely assigned to this film sensitivity. Now the original digital sensors were CCD's. A CCD was a semiconductor chip of photodetectors - a device that created a voltage ( collecting the charge) proportional to the amount of incident. This charge was marched off of the CCD for follow on processing. The amount of incident light energy necessary to generate the minimal detectable signal (charge) above the noise floor is the sensitivity. So somehow the concept of ISO was carried over. Wrong but no harm or confusion yet.

    Then the CMOS sensor arises. All a CMOS sensor is a chip which merges the photodetectors with the follow on processing (the off chip electronics in a CCD camera). That is the signal conditions, amplification and analogue to digital and quantization to a digital word (14 bits in many of our cameras today). So instead of a matrix of charge marched off of chip, we have a digital frame of data. Exposure relates to light power. Where the confusion results is that the brightness one sees in a jpeg is not really a function of the exposure but of the signal conditioning - particularly the amplification (into the ADC) and digital amplification (through curves in the generation of the jpeg output). All of this processing is controlled by the "ISO" one choses. There is no exposure triangle. There might be a brightness triangle.

    To talk about exposure one needs to consider the base sensitivity of the photodetectors in the sensor relative to the optical energy incident on the photodetectors. A appropriate exposure would be one that makes maximal use of the dynamic range of the photodetectors - a physical property of the sensor. However, that has little to do with the brightness of the jpeg. I can cut the light energy incident on the 3 dB (1/2) and get the same brightness by a combination of analogue amplification and digital amplification by 2.

    The digital standard for ISO has noting to do with sensitivity - which is how the ISO standard arose when the sensor was film and amplification was not really possible.

    So the evolution from film where "ISO" was more or less related to film sensitivity to light, was bastardized to some extent when the CCD EO chip came along but and then when the signal conditioning and amplification chip was integrated into the CMOS sensor - ISO evolved to have little meaning related to proper exposure.

  • Members 3973 posts
    April 10, 2023, 10:19 p.m.

    If shooting sooc jpegs then yes.

    If shooting raw and the aim is too maximise the quality of the raw data then:

    1. set the smallest f-number to give the desired DOF.
    2. set the slowest shutter speed that will meet blur requirements.
    3. set ISO to Auto and let the camera set image lightness where it sees fit. Final image lightness is set in post.

    If at base ISO important highlights are being clipped then you need to compromise on DOF and/or blur to avoid clipping.

    If there is highlight headroom raise ISO, because the exposure* has already been maximised for the artistic constraints, to push the histogram data as close as possible to the right to where clipping of important highlights occurs.

    * exposure - amount of light striking the sensor per unit area while the shutter is 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 2310 posts
    April 10, 2023, 10:26 p.m.

    Nikon disagrees : The ISO setting is one of three elements used to control exposure

    www.nikonusa.com/en/learn-and-explore/a/products-and-innovation/iso-control.html