[sharptrack2 (Kevin)]

G'day,

Please ignore the technical errors in the attached image. It was a quick grab of 7 frames (actually more, but only 7 were worth keeping). And I hope it uploads big enough to see at 200KB. If you can't tell it's Eta Carinae.

I've recently acquired an Astronomik 2" CLS filter to have a play with.

I'm reasonably happy with the output as far as getting longer exposures but am not happy with the blue/green tint that now has to be dealt with.

I normally set my white balance to daylight and get what I think are normal colours after processing. Now the whole image has this pale bluish tint that I cannot seem to compensate for. I did take a quick stab at one image in ACR and could negate it a bit with white balance adjustments, but then I would have to convert everything from RAW to TIFF, or FITS, to stack and I'm just not that ambitious at the moment.

So simple question is... can you compensate in camera or is the output always going to be missing a lot of red due to the filter response. The description suggests that it should be colour balanced so I didn't expect this.

Setup is Bresser Messier 127 f/5 on an HEQ5 Pro mount, no guiding. Imaging train is Nikon D7200 DSLR with 50mm extension, Baader fringe killer filter, and the CLS filter. Camera settings are WB daylight, ISO 800, 120 sec exposures. Focus was best that could be achieved using live view. Stacked with darks and bias only (thought... do I need flats to correct the colour?).

Thanks for taking time to read through!