A query on dual gain sensor

[Rohinton Mehta]

Can someone please clear my doubt?
I am taking the Nikon Z8 as an example. It has a dual gain sensor and the two ISOs are 100 and 800. This means (please correct me if I am wrong) that if I need to go higher than ISO 100 for any reason, it is better to go to ISO 800, as the noise level at ISO 800 is same/similar to that of ISO 100. Biut what happens to the dynamic range -- does it drop due to the higher ISO or does it remain the same as at ISO 100? Thanks in advance.

 

[DRwyoming]

Can someone please clear my doubt?
I am taking the Nikon Z8 as an example. It has a dual gain sensor and the two ISOs are 100 and 800. This means (please correct me if I am wrong) that if I need to go higher than ISO 100 for any reason, it is better to go to ISO 800, as the noise level at ISO 800 is same/similar to that of ISO 100. Biut what happens to the dynamic range -- does it drop due to the higher ISO or does it remain the same as at ISO 100? Thanks in advance.

Here's the Z8's Dynamic Range curve:

Basically the dynamic range at ISO 500 is very similar to the DR at ISO 200 to 250 or thereabouts so both shadow noise performance and overall DR between the two drops a bit before bumping back up around ISO 500.

Basically if you need to squeeze every bit of dynamic range out of the camera to deal with a high contrast scene in harsh lighting then it's best to shoot below ISO 200 or if you need more ISO then jump up to ISO 500. For moderate contrast scenes especially in softer light there's more than enough DR even in that ISO 200-500 range but if what you're shooting really pushes DR hard then it's probably best to shoot near base ISO or if you need at least ISO 200-250 or so then bump it up to ISO 500.

 

[John Navitsky]

while real, generally speaking i think the times one might care about this in the real world are exceedingly rare

 

[Cameron T]

Yep. And if it's that critical, you're likely bracketing anyway for the extremes to maximize the data quality.

 

[bleirer]

Canon has the dual gain also, the 2nd one at 400. If I have leisure to think it over I'll skip to 400, but who has time to think about it in the field for such a tiny benefit?

 

[Lee R]

I have not had a single issue with DR in the ISO range of 100-400 on the Z8. You can still pull shadows a significant amount and more than I’ve ever needed to in lightroom. I think these charts are useful to a degree but there’s a point where you’ve just got enough and it’s really no factor. You see people on youtube making a big deal out of this stuff by comparing side by side and pulling 6 stops out of an underexposed shot but who does that in real shooting.

As mentioned I would bracket it and merge if I knew the shot needed that much shadow or highlight range. For me it’s never been an issue.

Technically my older cameras like the D-750, Z-5 have much better dynamic range in that 100-400 setting but I can’t tell any difference in real world use.