X1D iso invariant?

[madlantern]

I know the X1D has great dynamic range at base iso. But what about iso-invariance? Is there a penalty to unde-exposing and pushing in post? Does it apply a secondary gain, like the A7R II?

[Bart_van_der_Wolf]

I know the X1D has great dynamic range at base iso. But what about iso-invariance? Is there a penalty to unde-exposing and pushing in post? Does it apply a secondary gain, like the A7R II?

According to this info, you'll lose DR at higher ISO settings until ISO 3200:
http://www.photonstophotos.net/Charts/PDR.htm#Hasselblad%20X1D-50c

Do note that the PDR (which is limited by a different noise floor level, and AFAIK pattern-noise) is not the same as Engineering DR, but the principle remains.

So underexposing will reduce DR, ETTR at base ISO maximizes DR.

Cheers,
Bart

[ErikKaffehr]

Hi,

It does not have dual gain conversion.

Best regards
Erik

According to this info, you'll lose DR at higher ISO settings until ISO 3200:
http://www.photonstophotos.net/Charts/PDR.htm#Hasselblad%20X1D-50c

Do note that the PDR (which is limited by a different noise floor level, and AFAIK pattern-noise) is not the same as Engineering DR, but the principle remains.

So underexposing will reduce DR, ETTR at base ISO maximizes DR.

Cheers,
Bart

[Paul2660]

A good source for ISO invariance is the test that Dpreview does.

Here is the test for the GFX which uses the same sensor.

https://www.dpreview.com/reviews/image-comparison/fullscreen?attr134_0=fujifilm_gfx50s&attr134_1=fujifilm_gfx50s&attr134_2=fujifilm_gfx50s&attr134_3=fujifilm_gfx50s&attr136_0=7&attr136_1=1&attr136_2=3&attr136_3=2&normalization=full&widget=487&x=0.039426783253638235&y=0.49279496191950456

It appears the 50MP sensor is not totally ISO invariant but closer than not.

ISO 100 pushed 6 stops is noiser than ISO 6400.  Where as ISO 200 pushed 5 stops to 6400 is very close to being the same.

Paul Caldwell

[bclaff]

I know the X1D has great dynamic range at base iso. But what about iso-invariance? Is there a penalty to unde-exposing and pushing in post? Does it apply a secondary gain, like the A7R II?

The X1D does not use dual conversion gain technology.
Dpreview has a good tool to visualize ISO Invariance but I prefer my Shadow Improvement chart
Most people would consider this ISO Invariant from about ISO 200 and up.

[madlantern]

The X1D does not use dual conversion gain technology.
Dpreview has a good tool to visualize ISO Invariance but I prefer my Shadow Improvement chart
Most people would consider this ISO Invariant from about ISO 200 and up.

Thanks for the reply! 

Pardon my ignorance but how should I read that chart and why does it suggest ISO 200 is the tipping point for iso-invariance? It looks to me the line increases until iso800 at least.

[bclaff]

Thanks for the reply! 

Pardon my ignorance but how should I read that chart and why does it suggest ISO 200 is the tipping point for iso-invariance? It looks to me the line increases until iso800 at least.

Most cameras rise some over the entire ISO range but here you note only about 1/3 stop improvement over that entire range.
That's probably within any slight exposure variance.
You can also go to the chart and compare that with other cameras.