In-camera processing of long-exposure RAW data

Started Jan 21, 2010 | Discussions thread
ejmartin Veteran Member • Posts: 6,274
Re: opening the can of worms a bit further...

bob elkind wrote:

Marianne,

The behaviour you've found and described is likely a big shock to many of us. The use of Nikon bodies for astro and macro photography is potentially seriously compromised.

Now that this can of worms has been opened, it would be interesting to apply a (hopefully) simple and concise test to various Nikon bodies and firmware versions to verify the extent of this 'feature'. Such a test would be very handy. How feasible is such a test?

Actually it's been known for quite some time, apparently just not around here.

The initial observation of something funny occurred when Peter Facey was doing sensor tests on a D3

http://www.brisk.org.uk/photog/d3snriso200.html

and noticed a weird kink in SNR at 1/4 sec exposures. He and I and Bill Claff discussed the issue, and Bill did some tests on a variety of models:

http://home.comcast.net/~NikonD70/GeneralTopics/Sensors_&_Raw/D300_and_D200_Do_Noise_Reduction_on_Longer_Exposures.htm

http://home.comcast.net/~NikonD70/GeneralTopics/Sensors_&_Raw/D300_and_D200_NEF_Files_Can_Be_Affected_by_Noise_Reduction.htm

http://home.comcast.net/~NikonD70/GeneralTopics/Sensors_&_Raw/D3_NEF_Files_Can_Be_Affected_by_Noise_Reduction.htm

http://home.comcast.net/~NikonD70/GeneralTopics/Sensors_&_Raw/D90_Does_Noise_Reduction_on_NEFs_at_Longer_Exposures.htm

I missed the effect in well-exposed images in the FFT probably because of the way the algorithm that Marianne has reverse engineered won't have much effect on the FFT in that regime. Bill did the test at low exposure and it shows up clearly there as you will see in the first link to his pages above.

-- hide signature --
Post (hide subjects) Posted by
eNo
eNo
eNo
eNo
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow