ISO50 on SL2 and Q2

[SrMi]

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[In the other thread that I started (SL2, ISO50, and overexposed JPEGs), ISO 50 discussion threatens to overpower the issue of live-view/image-review discrepancy.
Hence another thread.]

Summary of ISO 50 on SL2 and Q2:
- ISO 50 is native/base ISO, as measured by PhotonsToPhotos (extended ISOs can not have better DR).
- ISO 50 has a reputation for blowing highlights; that has nothing to do with DR but with exposure (as Bill Claff explained it to me).
- Blown highlights can occur with automatic exposure only. If you expose manually and adequately, no blown highlights should occur with any ISO.
- When compared to >=ISO100, ISO 50 should be exposed with -2/3EV to have same highlights protection.

[Dr. G]

I am finding that even if I dial back the exposure compensation to the point where the blinking overexposed highlights disappear, the image on the camera when reviewed will have a large area of blinking blowouts.  I have been told that this is because the camera is showing the jpeg.  It seems the RAW files are fine.  

The one thing I can't seem to figure out yet, is if color saturation is being preserved when dialing back to where the blinking highlights just start to disappear.  Going 2/3 to 1 stop under that point seems, to me, to provide better color saturation.

[SrMi]

54 minutes ago, Dr. G said:

I am finding that even if I dial back the exposure compensation to the point where the blinking overexposed highlights disappear, the image on the camera when reviewed will have a large area of blinking blowouts.  I have been told that this is because the camera is showing the jpeg.  It seems the RAW files are fine.  

The one thing I can't seem to figure out yet, is if color saturation is being preserved when dialing back to where the blinking highlights just start to disappear.  Going 2/3 to 1 stop under that point seems, to me, to provide better color saturation.

The larger area of blinking blowouts in image review is only at ISO50, not at >= ISO100, is that correct? It affects the saved JPEG (embedded JPEG, used in image review, and/or a separately saved JPEG).

I do not recommend using ISO50 if one is saving JPEGs as the live-view does not correspond to what is being saved.

[caissa]

The dynamic range of modern cameras is great (of all brands). So I see no need to think a lot about 100 or 50. For me the question is rather do I take 400 as default or 800. (I tend to 800).

[SrMi]

2 hours ago, caissa said:

The dynamic range of modern cameras is great (of all brands). So I see no need to think a lot about 100 or 50. For me the question is rather do I take 400 as default or 800. (I tend to 800).

My point is about a large discrepancy between the histogram/blinkies in live-view vs. image-review at ISO50.

DR of modern cameras is excellent. But why waste image quality with higher ISO when unnecessary? The shadow noise difference between ISO100 and ISO400 is considerable.

[caissa]

I never needed to correct noise in shadows. But there are now AI tools that do this so perfectly, that I would not get into trouble if ever I needed it. So I think the time to worry about that is over for me.  e.g. Topaz DeNoise AI

See in this thread.     

 

Edited September 3, 2020 by caissa