by arthurking83 » Sat Sep 13, 2014 5:48 pm
D800E:
Took various test images, in almost complete darkness. vf shutter closed, lens cap on, camera under the desk to maintain darkness as best as possible.
6 test shots each @ ISO100, 400, 800, 1600, 3200 and 6400(just to see any differences in rendering).
First set of images with NikonBlackLevel(NBL) set to enabled in camera look fine.
All images look good, a noticeable difference in black level from ISO100 to 400, and a steady increase in RGB levels from there on.
ie. where ISO 100 is black (0,0,0) ISO400 is more like 3-4 RGB values.
The difference between images with black level enabled and those where its reset back to disabled is a marked one, especially compared to the images with LNR set to ON(which has been my preference for most low light photography.
BUT! .. a second series of test shots with NBL set to enabled in camera .. all 6 images rendered a solid magenta colour. (ie. some kind of data problem ???).
The magenta image's RGB pixel values area pretty steady 135, 62, 108 across the entire frame. ie. a solid magenta coloured frame .... not magenta banding or smudges or various hot pixels here and there.
Now every time I set NBL to on, I only get these magenta images(or images with a very strong magenta cast over them)
With NBL set to off, the camera operates as per normal.
If I capture a normal image(as opposed to a dark frame) with NBL on there is a very strong magenta cast over the image and exposure appears to be around 1-2Ev too bright compared to the same exposure with NBL set to off.
I note that when NBL is enabled in the camera, the option to turn LNR on or off is disabled. At this point I'm assuming that NBL is set to on.
Upon resetting the camera, the option to enable/disable LNR is returned, which I assume NBL is now off again.
If this is not normal, I can provide raw images if you need them for analysis.