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Old 17-03-2013, 04:10 PM
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LewisM is offline
Join Date: Aug 2012
Location: Somewhere in the cosmos...
Posts: 10,326
Colour conversion issues

Recently bought an SXVR-M25C OSC CCD. Really nice camera, but I have some issues.

The B&W FITS images are nice, but when I run the colour conversion, in either the SX software or Maxim DL, I either get NOT MUCH colour, or ODD colours - for instance, last night's M83 was almost entirely purple, other stars and all!

Running m42 thorough it reveals basically nothing - no red, little blue, and importing a converted TIFF into PS leaves me with obvious stretch artifacts etc, as well as usually some remnant of the FITS matrix!

What the heck is going wrong here!?

I did NGC 3324, and it shows some red in SOME of the photos, yet others later will be predominately purple again.

Does this sound like a hardware/software issue, or am I just not doing things right?

And it's being a NIGHTMARE to stack anything after colour conversion too (which MUST be done prior to stacking of course) - all subframes are wrong size/channel etc, (unless I bin the lights 2x2), and even then, I end up with a pixelated mess of a result. I am more or less limited to single images (crap detail / colour) because of this stacking weirdness. And if I use the continuous image function, it adds the new data on top of old... great in theory, but usually get field rotation after 4 x 5min subs, meaning throwing out EVERYTHING! (learnt that the HARD way!)

Starting to pull my hair out here! Some shots look FINE prior to conversion, then after, there will be pixels everywhere and no detail etc. Was getting better results with a DSLR!

Any tips / ideas?

Does any available software auto-colour convert without having to do all the 100000 dance steps of Maxm and SX software? CCDautopilot??? I am now using Maxim, but figuring out flat/bias subtraction is a nightmare.

Attached are some samples - the BETTER ones!

Lastly, if I set the temp to -40 on a 27 night, it will get to about 0.9, then start increasing again to about 3.8 = this does not seem right.
Attached Thumbnails
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Click for full-size image (3324.jpg)
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