• Members 2303 posts
    April 18, 2023, 1:18 a.m.

    exactly , until you get into clothing which i shoot a few clothing sponsored dancers in my studio and my colours and brightness of those colours have to be perfect. especially Fluro colours , must admit my sony a74 is fantastic for colour reproduction when shooting extremely colourful costumes. nothing worst than bright fluro light green turning into yellow.

  • Members 3924 posts
    April 18, 2023, 1:36 a.m.

    That is pretty much the general principle I follow as well for BIF except I'm usually at around f/8 for DOF needs. But that's just my preference.

    But in the situation you describe where you have changing conditions I set a minimum shutter speed as well. So in the situation you describe with changing cloud conditions I would set 1/1600s, or the slowest I knew I can still freeze motion at, minimum shutter speed. That way if it became very bright suddenly, the camera automatically compensates by setting a faster shutter speed to 1/2000s or whatever it needs to prevent highlight clipping.

  • Members 75 posts
    April 18, 2023, 2:43 a.m.

    Mechanical Engineer here, BS & MS. Nice to meet some "normal" people!

    I was required to take 3 semesters of physics, the last was the equivalent of quantum mechanics for dummies (non-physics majors). I learned everything is just a fuzzy ball of probability. I'm the guy who is supposed to work with gears, engines, pumps, and piping. Who thought up that requirement?

  • Foundation 1468 posts
    April 18, 2023, 7:24 a.m.

    Actually, believe it or not, I had never heard of the „exposure triangle“ until I came across this discussion. Now I have met it, it reminds me of the Bermuda Triangle.

    David

  • April 18, 2023, 7:33 a.m.

    I absolutely believe you. If you learned before the invention of the 'triangle' you would be unaware of it. I only became aware because I found people telling me that I didn't know anything about exposure because the triangle. It didn't take very long to work out that there was a correlation between those that didn't know anything about exposure and those that adhered to the triangle.

  • Members 50 posts
    April 18, 2023, 7:45 a.m.

    If it was engineer against physics major, I'd have less problems with this posting. I have done math against software engineer professionally. But some ideas here sound more like philosopher against photographer.

  • April 18, 2023, 8:38 a.m.

    I'm intrigued to know which ideas you mean. I haven't seen anything put forward which isn't either accepted as core photographic theory since the end of the 19th century or isn't just the basics of how modern digital technology works.

  • Members 142 posts
    April 18, 2023, 10:59 a.m.

    Sadly, there's a third group who know it's wrong and teach it anyway.
    Sherm

  • Members 509 posts
    April 18, 2023, 11:20 a.m.

    I have been setting exposure via the histogram for years. I shoot a picture, check the histogram, adjust shutter and aperture so it's up against the end stop without clipping any important highlights I wish to retain texture in. If insufficient exposure is indicated by spare room on the right side of the histogram, I reshoot. Mirrorless cameras with preview histograms make this quicker and easier. I also have zebras set to the highest value my camera supports (105%). The caveat is lack of confidence in the jpg histogram. I always think there is probably room to boost exposure even higher for raw shooting, but I never quite have the nerve to deliberately clip. I don't care what the preview image looks like, I sort out the tones in editing.

    Judging by the contents of this thread, that probably means I've been doing it right all along. At least I hope so 🙂

  • Members 3924 posts
    April 18, 2023, 11:26 a.m.

    Well.......right or wrong seems to be a hotly debated issue 😊 .......but it's certainly the way I set exposure* now 👍

    Fwiw, in my experience I know I have about 1/2 a stop of extra exposure* after the camera's histogram shows clipping before the actual raw data is clipped.

    * 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 509 posts
    April 18, 2023, 11:31 a.m.

    Let me have a go at interpreting this picture with an example. My wife accidentally set her camera to ISO4000, then shot 2 week's worth of wildlife photography in blazing Namibian sunshine. The resulting images are very noisy, despite the intense sunlight.

    So, what she did by setting ISO4000:
    i) boosted amplification, resulting in slightly reduced read noise in the shadows.

    ii) She also told the camera to underexpose by 6 stops (and boost brightness to disguise this) resulting in a massive increase in the contribution of photon shot noise and thus a commensurate reduction in SNR. This also increased the risk of clipping.

    EDITED: Conclusion: The increase in shot noise vastly outweighs the reduction in read noise, significantly lowering SNR, hence the excessive overall noise despite the bright sunny conditions.

    Do I have that about right?

    Cheers

    Dave

  • Members 3924 posts
    April 18, 2023, 11:43 a.m.

    Pretty much, but I would have explained it slightly differently so I'm being a bit picky.

    Fwiw, it is a low Signal to Noise Ratio that makes noise visible.

    The higher the exposure*, the higher will be the SNR and so the less visible will be the noise.

    On a side note, did your wife really not notice for the whole 2 weeks that ISO was at 4000? 🤔

    * 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 976 posts
    April 18, 2023, 11:47 a.m.

    That plus wanting details where SNR is low.

  • Members 509 posts
    April 18, 2023, 11:56 a.m.

    I think I mentioned SNR in ii)

    My wife hardly ever shoots with a dedicated camera, she's happy with her phone. The only time she shoots with a camera is when she does wildlife stuff. We spend some time refreshing camera operation before she goes, but she's not really prepared to sit down and spend a long time ingraining good habits.

    Her first trip, she had a point and shoot and got awful results.

    Her second trip she took a D100 and the Nikon 70-300 AFD which is not a lens known for its sharpness at 300mm with the inevitable much softer results than her friend got with her Canon 300D and 70-300mm IS USM lens.

    Her third trip she took a bridge camera and a m4/3 camera and got pretty decent results for an occasional amateur. But she had a lot of problems with the cameras - particularly the bridge camera whose lens is very sensitive about getting knocked and shuts the camera down. The lens got knocked a lot during the trip, very frustrating.

    For the latest trip, she had a new DSLR, image stabilised silent focusing lens, monopod... We practised before hand... Everything looked positive... But... she wanted to take photos of the glorious dark sky star fields. We has also practised this, choosing ISO and shutter speed to avoid star trails. And I think the ISO4000 probably came from that practice. And no, she didn't notice, because she's not an experienced photographer technically, and doesn't notice anything to do with the settings.

    We're beginning to think her wildlife trips are cursed. Maybe I'll have to go with her and supervise (I'm not a fan of doing wildlife photography. Far too frantic).

  • Members 142 posts
    April 18, 2023, 12:03 p.m.

    Your priority should be to avoid being blamed for the problem.

  • Members 509 posts
    April 18, 2023, 12:09 p.m.

    Went back and tweaked my conclusion to reflect your comments.

  • Members 3924 posts
    April 20, 2023, 6:11 a.m.

    Fixed it for you 🙂

    Since in another thread you said

    * 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.