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Re: Dark Current Enable Tool

PostPosted: Mon Sep 15, 2014 7:22 pm
by astronomer

Re: Dark Current Enable Tool

PostPosted: Sun Sep 21, 2014 4:43 am
by Iliah Borg
I was under impression D810 does not subtract the black level, as the black is around 600, also listed in Makernotes tag 0x3d.

Re: Dark Current Enable Tool

PostPosted: Sun Sep 21, 2014 7:27 am
by astronomer

Re: Dark Current Enable Tool

PostPosted: Mon Sep 22, 2014 8:10 am
by Iliah Borg
The black frame http://s3.amazonaws.com/IliahBorg/Nikon ... C_1261.NEF
Also, you can check the black level with RawDigger or exiftool (we reported the tag to Phil, and it is processed by exiftool since we discovered it in D5300/D3300). The tag value is to be divided by 4 if the file is in 12-bit mode (not applicable to Nikon's sRAW).

Re: Dark Current Enable Tool

PostPosted: Mon Sep 22, 2014 2:00 pm
by astronomer

Re: Dark Current Enable Tool

PostPosted: Mon Sep 22, 2014 2:17 pm
by Iliah Borg
> I would like to see a dark frame with long exposure, say 5 minutes

I will try to arrange for one.

Gaps in colour channels
Image
- Looks to me like Nikon's white balance pre-conditioning, same as on a regular shot
Image

What you have achieved is a major breakthrough.

Re: Dark Current Enable Tool

PostPosted: Mon Sep 22, 2014 2:55 pm
by astronomer

Re: Dark Current Enable Tool

PostPosted: Mon Sep 22, 2014 3:29 pm
by Iliah Borg
> Also visible is the digital scaling related to aperture value, which is really annoying.

I tend to use lenses that have manual aperture control, like enlarger lenses (they have wider spectral transmittance anyway)

> It appears D4s has black level as well.

True, and any expeed 4 -based camera would be a good candidate to check black level.

Re: Dark Current Enable Tool

PostPosted: Mon Sep 22, 2014 9:02 pm
by Simeon

Re: Dark Current Enable Tool

PostPosted: Tue Sep 23, 2014 5:05 am
by Iliah Borg