Thread: QSI Arrives
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Old 26-08-2009, 09:18 PM
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gregbradley
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Join Date: Feb 2006
Location: Sydney
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Great looking camera.

I recommend you standardise your image lengths. 10 minutes is a good length.

Also the temperature. In winter you will be able to get a camera down to -25C without too much trouble. In summer it may only get to -15C. Not sure how much your camera will cool.

So take 12 darks at -25C 10minutes each 1x1 binning. Make a master dark in CCDstack and use sigma reject for combining them.

Now take 8 bias frames and make a master out of them.

Now do the above again but for 2x2 binning. That is for your RGB exposures where most people use 2x2 binning.

When you are ready to image have your setup focused and camera in the position you will image. Now take some dusk flats. Put a white T-shirt over the end of your scope, point the scope 10 degrees above the horizon towards the west where its evenly illuminated. When its twilight take 3 shots each of at least 3 seconds long and so you get a reading of around 21,000 from the image (about 1/3rd saturated).

Do this rapidly for each LRGB. So Luminance is usually imaged at 1x1 binning so do those flats at 1x1. Do the RGB flats individually and the camera set to 2x2.

Make masters out of your flats and subtract the bias you made above from it. You don't need the bias again after that.

When you are ready to start the image at night, do 10 minute subexposures at 1x1 for luminance and 10 minutes at 2x2 for RGB.

A common exposure time is 6x10 for luminance, 3 x 10 each for RGB.

Then you process these in CCDstack. callibrate by dark subtract and flats. Then data reject removing hot/cold pixels then register to align and then save as a master file for that LRG or B.

Then when you have masters for each of the LRGB you do a colour combine.

Then you save and switch to Photoshop where the first step is to use levels/curves to bring the image up.

Sounds like a lot but its not really.

Greg.
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