Native ISO for M10M?

[davidbaddley]

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Just got my new M10M (Yay). On my old M9M, 160 ISO is called PULL, which makes sense because of the lack of the Bayer Filter (making 320 native). I see that no such designation is made on the M10M. is 160 a PULL ISO, like on the M9M, or is 160 really the native ISO with this sensor?

 - David

 

[Leica001]

Native ISO

[Jeff S]

Red Dot Forum describes and tests it as native 160.  But the following discussion, and reference to Sean Reid’s review, offers some alternative views.

Jeff

[Ken Abrahams]

I mostly use 400 iso on the M10 now. I range settings between 400-800 iso for general scenes unless I am needing to use wide open and need the exposure to work. Sometimes I wish the camera had 1/8000 sec exposures available, rather than having to use the ND filter. 

[Gobert]

Or better, lower ISO, instead of 1/8000.

Since this M10M I use auto ISO for the first time in my carreer. I think I like it.

[strohscw]

vor 9 Minuten schrieb Gobert:

Or better, lower ISO, instead of 1/8000.

Since this M10M I use auto ISO for the first time in my carreer. I think I like it.

So do I, but I wish I could also set the lowest ISO value, because then I would set it to:  400-12500. This would make my M10M perfect.

[Gobert]

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I would choose 20-25.000

[Keith (M)]

From the review I read (as a subscriber), 160 & 320 are considered a 'pull' and native to be in the region 400 - 640.  Must confess though that in nine months of use most of my shots have with Auto-ISO set and it is a shame that (as mentioned in post #5) that one cannot set a preferred minimum in Auto-ISO.

[SrMi]

PhotonsToPhotos measurements show that that the native ISO is 160 (aka highest dynamic range).

https://www.photonstophotos.net/Charts/PDR.htm#Leica M10 MONOCHROM

Because of how a pulled ISO is implemented, some reviewers use highlight recovery to determine native ISO. Highlight headroom and dynamic range are not related. By the definition of native ISO, the highest dynamic range is at native ISO, unless the camera adds some NR or similar.

We are interested in native ISO to determine where the camera has the most DR, which is close to ISO 160. If we are curious where the least highlight clipping occurs with automatic exposure measurements, then it is at higher ISOs.

This confusion about native ISO is typical for Leica cameras. The information that I received from Leica about pulled ISO for SL2 and Q2 does not match what is being measured. 

Edited November 27, 2020 by SrMi

[davidbaddley]

I'm not sure that highest dynamic range = native ISO. A pulled ISO could add a stop to dynamic range, but if it achieves this by just adding neutral density to the highlights it isn't really indicative of the true native behavior of the sensor.

 

 

[SrMi]

29 minutes ago, davidbaddley said:

I'm not sure that highest dynamic range = native ISO. A pulled ISO could add a stop to dynamic range, but if it achieves this by just adding neutral density to the highlights it isn't really indicative of the true native behavior of the sensor.

Adding a neutral density filter for highlights helps manage the scene's dynamic range (DR). It does not change the camera's DR.

Dynamic range (DR) can be seen as the range from a fully saturated sensor (no clipping) to shadows with a certain noise level. Once we raise the ISO above native ISO, we also amplify the noise in the shadows, thus reducing the DR.

P.S.: The camera has plenty of DR, and shooting ISO 160 or ISO 400 should not degrade DR significantly.

[davidbaddley]

Thank you, this has all been very helpful.

 

[davidbaddley]

Oh, and I didn't mean adding a neutral density filter, I meant adding neutral density to the highlights in camera, as apparently the M9M did in the PULL 160 setting. Using this ISO moved acceptable noise level a stop further into the shadows (increasing overall dynamic range of the camera), but it compromised the highlights to do so (although minimally). While giving acceptable results, I don't really consider a pulled ISO to be a native ISO.

 

 

 

[SrMi]

36 minutes ago, davidbaddley said:

Oh, and I didn't mean adding a neutral density filter, I meant adding neutral density to the highlights in camera, as apparently the M9M did in the PULL 160 setting. Using this ISO moved acceptable noise level a stop further into the shadows (increasing overall dynamic range of the camera), but it compromised the highlights to do so (although minimally). While giving acceptable results, I don't really consider a pulled ISO to be a native ISO.

 

Pulled ISOs can help noise in shadows while compromising highlights. They cannot increase DR and can be simulated manually with appropriate camera settings (overexposure) and post processing (decreasing brightness). The DR is measured from non-clipped highlights to the floor noise.