Quote:
Originally Posted by alistairsam
could you explain light frames as well? are they the actual image frames?
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Yes - your data images.
Quote:
Originally Posted by alistairsam
what is ADU? "So if your camera is a 16bit camera, shoot to reach 10k or 20k ADU."
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ADU is a measure of the brightness of a pixel in your pic. If you have a 16 bits camera the full well is 65536.
Quote:
Originally Posted by alistairsam
"whatever duration will give you approx 1/3 of your camera full well." is this 1/3rd of the exposure time for the image frames?
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20000 ADU would be about a third of the total illumination your camera is capable of. Anything above 65K will be 'burnt out' (i.e. true white). So you need to set the illumination or time you exposure to reach that maximum level in your flat.
Quote:
Originally Posted by alistairsam
also, what are the lightboxes used for? i've seen a few black boxes with white insides at the end of a few scopes at snake valley.
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I use a small A4 EL sheet for convenience but you can use a light box as well. Anything that gives you a relatively uniform illumination across the aperture of your scope. Many people shoot sky flats as well at dusk or dawn.
Quote:
Originally Posted by alistairsam
for dark frames, is it acceptable to just cover the ota instead of the camera lens opening?
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Yes - you can cover the scope but I wouldn't shoot darks in daytime in case of light leaks. Do it just after your imaging session or before while is still dark(ish). If you have a temp controlled camera then you can do it later in a dark room and build a library of darks.