Q3 50 vs 100 ISO results

[Miltz]

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After finally get my Q3 my testing began. I shoot a lot of landscapes and knowing how the camera responds to these settings is critical for me. Please let's not get into what the native ISO is, it really doesn't matter. What matters is how they work and what results they produce. All my testing was done in M-DNG RAW as it produces the best overall dynamic range. I will say that for most people the results don't affect their shoot because pushing and pulling images this much isn't common, including my own. But their are some things to know which can affect your images, so lets get on with it.

When comparing 50iso to 100iso in an underexposed scene and raising the exposure and shadows up to 5 stops it's clear the camera is handling the data differently. All of the 50iso shots had a green cast to them while the 100iso shots leaned more towards magenta. 100iso is more color accurate in my opinion than 50iso but the 50iso shot can be corrected in Adobe Camera raw to look almost like the 100iso shot. Note the camera's white balance was identical for both shots, it's the ISO settings that affected the shadows. What about noise in the shadows? Well the 50iso was a tiny bit cleaner in the shadows, but the difference was so small I doesn't really matter, at least to me. When you factor in the green color cast I don't see any benefit shooting at 50iso over 100iso unless you obviously need to. I would be comfortable using either one in the field, but 100iso is going to my default. 

When comparing 50iso to 100iso in an overexposed image the differences are much more apparent. First 50iso clips the highlights to a much higher degree which makes them much less recoverable than shooting at 100iso. Second now when lifting the shadows and exposure the green cast is basically gone and both images look the same when it comes to colors. Third, there is now a difference is shadow noise that benefits 50iso. The 50iso image has less visible noise when compared to 100iso. 

 

So what does this all mean? Well knowing is the most important and how you choose to use the ISO will depend on your shooting Preferences. For me personally I will use 100iso whenever possible, at the same time if I need to use 50iso I won’t hesitate to use it as long as I’m extremely mindful of my highlights. For example, in a studio environment with soft light I wouldn’t hesitate to use 50iso if I have an ideal exposure. Outdoors for faster paced shooting especially of sunsets and other high contrast scenes, I’m going to stick to 100iso.

 

[SrMi]

Avoid ISO 50 as it has weird properties.

M-DNG has the same DR as L-DNG.

[Michael Pace]

On 9/6/2023 at 2:37 AM, SrMi said:

Avoid ISO 50 as it has weird properties.

M-DNG has the same DR as L-DNG.

My understanding is that on the Q3 is ISO invariant and DR is higher in M-DNG to the tune of a full stop. There is video that is comprehensive on this subject and it clearly confirms this

[jaapv]

I suspect that ISO 50 is a pull value. 

[SrMi]

1 hour ago, Michael Pace said:

My understanding is that on the Q3 is ISO invariant and DR is higher in M-DNG to the tune of a full stop. There is video that is comprehensive on this subject and it clearly confirms this

No, Q3 is not fully ISO invariant and M-DNG does not have higher DR.