UPDATE: Unfortunately the hot pixels can NOT be ignored when disabling the noise reduction, so unless you manually create a dark frame after the shot it's pretty much pointless. Proof, the following two images:
|Crop from a 30 seconds exposure of the night sky|
|Crop from a "star trails" 1 hour exposure (hopeless indeed - the pink thingy isn't because of white balance :D, it's pure noise)|
I've finally found a way (about an year ago but I was too lazy to post it here) to disable the forced noise reduction of my Samsung Gx20 camera - that I'd mentioned here. Many thanks to the guys from Pentax-hack.
As they say on their site, basically you have to create a text file in the root of the memory card (called "MODSET.454" for GX20 v1.01, v1.03), and enter the proper commands in the file ([DEBUG_MODE EN] Enables debug mode; [DEBUG_MODE DIS] Disables debug mode).
You will also need SYSPARAM.TXT file, in which various internal parameters are set (among which the ones related to noise reduction ;) ).
Here are the setting that I use:
[FORCENR] 0@[DISABLENR] 1@[DISABLEBLC] 1@
For more info see: http://www.pentax-hack.info/index.html