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Old 28-05-2008, 04:46 PM
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seeker372011 (Narayan)
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Join Date: Oct 2004
Location: Sydney
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Quote:
Originally Posted by ozstockman View Post

I have however few questions about taking flats and bias frames with QHY8 because I don't think I did it right.

1)Should bias and flat frames be taken with the same gain and offset settings as for light frames? I forgot what settings I had for light frames for the image below and I guess this is why it's not the best result I could get with this great camera.


2) How to figure out the best exposure length for flats? I used to use Aperture priority mode in my Canon DSLR and the camera did it for me. But of course it's not possible to do with QHY8.

And if I get it right I shouldn't use binning for light frames if I want to get a color image, right? I used 2x2 binning and it seems that I lost all color details for this image.

thanks in advance,

Mike
I am sure others will pitch in but here's my take

the answer to question 1 is no !

I use a few milliseconds for bias and much much lower gain for flats than I do for lights. When I used the same gain the flats did not work..the dust marks were not divided out of the final image

one way to determine the best exposure for flats is to look at your histogram..see the exposure that moves it about halfway


oh and most certainly you should shoot in colour at 1 x 1

Narayan
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