Hi,
I have an ASI1600MC and after reading many forums, mainly Cloudynights and then on French forums, i have got the conclusion that for CMOS cameras offset images are irrelevants.
Instead we must use a FlatDark, which is a dark with the same duration as the flat images. Then a special process is applied to build the masters. I can give more details on the process if needed.
In SC i see only the traditional way with Dark, Flats and Offsets.
have u considered introducing this special CMOS way of building masters including FlatDark instead of Offsets ?
And additional question : i can see that we have the ability with SC to build monochrome flats which seems to be useful for colour cameras. Is this a recommendation to build monochrome flats in order to avoid any impact on the color balance ?
Regards
Bernard
DarkFlats
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'+1' posts are welcome in this area of the forums to indicate your support for a particular feature suggestion. Suggestions that get the most +1's will be seriously considered for inclusion in future versions of SharpCap.
'+1' posts are welcome in this area of the forums to indicate your support for a particular feature suggestion. Suggestions that get the most +1's will be seriously considered for inclusion in future versions of SharpCap.
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Re: DarkFlats
Hi,
SharpCap already has the option to capture and subtract bias frames when creating flat frames. The bias frames are just short exposure flats that help remove the offset level from the calculated flat field correction. In my opinion, providing your flat frame exposures are less than one second, there is no point in taking true dark flats when capturing flat frames – the amount of thermal noise building up in a CMOS camera in some one second exposure is really not worth worrying about, particularly at low gains.
The use of monochrome flats is really a matter of taste – using a monochrome flat will not adjust the colour balance of the saved images and may make it easier to get a nice colour correction later. Using colour flats effectively white balances the flat corrected image and may give better colour results if you are live stacking.
Cheers, Robin
SharpCap already has the option to capture and subtract bias frames when creating flat frames. The bias frames are just short exposure flats that help remove the offset level from the calculated flat field correction. In my opinion, providing your flat frame exposures are less than one second, there is no point in taking true dark flats when capturing flat frames – the amount of thermal noise building up in a CMOS camera in some one second exposure is really not worth worrying about, particularly at low gains.
The use of monochrome flats is really a matter of taste – using a monochrome flat will not adjust the colour balance of the saved images and may make it easier to get a nice colour correction later. Using colour flats effectively white balances the flat corrected image and may give better colour results if you are live stacking.
Cheers, Robin
Re: DarkFlats
Bernard
Not very rigorous, how about this - forget about Live Stack (that just adds complexity). Capture an image in the traditional way. Process with darks/flats/offsets and the way you are suggesting. Post back with a comparison. If you can demonstrate a tangible improvement then the process merits consideration.
Let the images do the talking …...
Dave
GroupThinkafter reading many forums ….i have got the conclusion
Not very rigorous, how about this - forget about Live Stack (that just adds complexity). Capture an image in the traditional way. Process with darks/flats/offsets and the way you are suggesting. Post back with a comparison. If you can demonstrate a tangible improvement then the process merits consideration.
Let the images do the talking …...
Dave
Re: DarkFlats
+1 for the idea of a dark flat routine