Astroart Forum

Hi,

I have used the Preprocessing tool fine. However, I wonder if there a way to produce individual calibrated subframes without stacking them?

The reason why I ask this is to process multi-night data. Currently AA5 can only process one set of data (one set of light, dark, flat, etc). I have been told to stack each night individually, and then overlay stacked_image_nite1 + stacked_image_nite2 +stacked_image_nite3 together.

I would like to calibrate all light frames by their corresponding dark and flat, and then stack them all together without dark and flat calibration.

Thanks for the hint.

Puck

Hi,
If you cannot reuse your darks/flats for all series then you need different preprocessings, but you can keep the result image of each preprocessing opened in the Astroart desktop for a final preprocessing on them (in memory, without dark/flats).

"Subframe" usually refers to a small part of the CCD. In preprocessing the dark/flats are always applied to single images, not to the result. You may consider also the option "save each image" to save all calibrated images on disk for a final preprocessing on them.

Hi,
"Save All Images" is exactly what I was looking for. I kept looking into the "Extra" tab but failed to find it in the "Option" tab. Silly me. Thanks a lot. Now I can process each set to get all "frames" calibrated but without stacking. Then, I stack all calibrated frames into final image.

Sorry for the "wrong" terminology. I guess it maybe wrong one from Astronomy discipline, but it seems to be commonly "misused" by the amateur community. By "subframe", I mean the each individual shots before being stacked.

Thanks for the help!!

Fabio:

I have successfully generate individual calibrated shots. I notice that the file size became 6 times larger (raw file: 12MB -> calibrated and color converted file: 72MB). I wonder why there is such increase on size. This makes storage and transferring of calibrated file more demanding.

Thanks for the insight.

Hi, if the input files are from a DSLR, then they are actually B/W files with bayer dithering. Converting to RGB requires 3X space. Another 2X is caused by lack of compression and promotion to 16 bit per channel.