Flats AFTER Livestack problem

[jhelum7]

Hi Folks

after using live stack and saving ins FITS type file foremat, when I try to capture flats later in sharp cap and THEN
try to combine the flats in deep sky stacker with the Lightframe composite from Sharpcap, the DSS gives me an error and says
the files are incompatible. How is one supposed to do FLATS and be able to combine them with a stacked image from Live stack later on.
Is it the file format (FITS) that is causing problems? any ideas
thanks

[admin]

Hi,

DSS is complaining because the image that is saved from the live stacking will be a full-colour image while the flat frame will be a single channel RAW (non-debayered) image.

You don't need to work around this issue – instead you need to change your workflow so that darks and flats are applied in SharpCap while the live stacking is happening. If you try to apply darks or flats in DSS or other processing applications after the live stacking has made a composite image then you won't get good results – this is because one of the key features of the live stacking is that it aligns each new frame with progressing stack to account for frame drift and/or rotation. If you try to apply darks or flats after this alignment process has already happened then they will not correct correctly.

Cheers, Robin

[jhelum7]

thanks for the quick response and I completely understand. For Darks, I "do my darks first" before the imaging session because I roughly know my livestack settings on certain deepsky objects. Then I point livestack to the dark folder under the pre processing tab.

My problem comes in for flats. How do I do flats first? I say this because for flats, the entire imaging train, camera position even focus should remain essentially untouched from the "lights". How can I pre focus for flat frames, get those first, and then do my imaging, changing focus certainly and possibly camera position later for my lights. It would seem flats should always come "after" light frames.

[admin]

Hi,

I would usually capture flats once I am set up to image by putting a sheet of white paper over the end of the telescope and using a torch or phone light to illuminate it. If you rotate the camera on the telescope or change filter then you'd need to redo your flats, but I tend not to bother for small adjustments to focus – the sort you make during an imaging session.

Cheers, Robin