Started Mar 26, 2013 | Discussions thread
mosswings Veteran Member • Posts: 8,616
Re: Color shift is more troubling

Horshack wrote:

mosswings wrote:

Horshack wrote:

I've been meaning to post my results but haven't gotten around to it. The banding is correctable but the color shifts on the D7100 shadows when pushed are not, at least not easily. theSuede says it's the result of of the green channel having to be pulled up a few ADUs above the other channels, whereas the Sony sensor doesn't have that problem.

Horshack, can you provide a link to theSuede's posting?  I can't seem to find his username in the forums, only your references to it.  I'm curious as to why this green pull was necessary.  It sounds like this is an amplitude=dependent RAW cook, but what I don't understand is why it doesn't cause an overall green color cast.  Perhaps that earlier posting about "green shadows" was on to something?

Sure, his post is here. It's specific to the shadows and Nikon's black clipping, which according to theSuede has to be perfect across the channels to avoid color casts in the deep shadows.

Fascinating.  The Nikon clipping issue raises its ugly head again.  I've always wondered if some of the DR differences between Canon and Nikon arise from Canon setting the black point 2-3 bits above absolute black to provide a balanced distribution around "black" while Nikon just truncates the distribution.

But what's interesting in TheSuede's comments are two things:

1.) this happens ONLY at low ISOs, so if you're wanting to use the camera in the 400-3200 range this shouldn't be a problem.  Of course, you're also operating at reduced DR with reduced shadow pulling capacity, but any pulling you do should be less tone-shifting.

2.) Sony sensors shift colors as well, but to the blue, and only at high ISOs.  However, blue shadows are a bit more acceptable than green ones.

All this makes for a camera, as Jim Pearce has said, is rather "edgy"; it can bite you if you push it too hard, and D5100/D7000 shooters are now conditioned to being able to push their sensors hard.

I'm still wondering why given this Nikon moved away from the Sony sensor.  About the only neutral reason I can think of, as previously posted, is that the next-gen Sony 24MP DX sensor wasn't ready in time and the NEX-7 sensor wasn't good enough/too obvious.  More conspiratorially, maybe that next-gen Sony sensor is being saved for the FF and Pro bodies. A D400 needs more than just build, buttons, and buffer to distinguish itself from the D7100.  Perhaps that distinction is a better sensor...

 mosswings's gear list:mosswings's gear list
Olympus XZ-1 Olympus Stylus 1 Nikon D90 Nikon D7100 Nikon AF-S DX Nikkor 18-105mm f/3.5-5.6G ED VR +5 more
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MOD Mako2011
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