Originally posted by bossa Here's an OOF dud shot that shows pink/purple glow in the darks. This is Amp Glow on my D800E.
That looks like thermally-increased leakage current in the sensor. "Amp glow", at least in the old days, was asymmetric due to the close proximity of hot elements, e.g. readout amps, ADC(s) or the image processor, to the sensor, causing non-linear hotspot gradients on parts of the sensor. See Fig. 6 here:
Noise, Dynamic Range and Bit Depth in Digital SLRs
Whereas the "amp glow" in your night-time shot is more generalised. Perhaps, better to refer to this as "dark-current noise" :
http://www.truesenseimaging.com/component/docman/doc_download/75-ccd-image-sensor-noise-sources
.
Whatever, doesn't your raw processor offer a dark colour deflection (Green-Magenta) adjustment to handle this?
Here's the section from the SilkyPix manual that explains what causes the coloured dark regions and how to fix them:
Why do color casts occur in the dark portion?
This is caused by current leakage of an image sensor. Because of the leakage current, the intense black is not recorded as zero value in RAW data. SILKYPIX® Developer Studio Pro 5 is subtracting such leakage current data from RAW data (optical black correction) to develop an image.
However, a higher temperature increases leakage current of an image sensor, and vice versa. In most cases, a camera records black with constant level, regardless of the temperature, but some conditions or photographing environment may affect the level (optical black level). According to the color sensitivity of each image sensor, as the optical black level becomes larger, the color of the dark area becomes magentish, and as the level becomes smaller, the color becomes greenish. The "dark adjustment" function reduces coloring of the dark portion in those cases. It also corrects the white balance of the dark portion when a photograph is taken under severe conditions such as extremely low temperature, high-sensitive photography, and long exposure.
You can make corrections without affecting brighter areas because dark adjustment is performed after exposure bias in SILKYPIX® Developer Studio Pro 5.
Dan.