DSS and pre and post meridian flip.

[White Rabbit]

Hi guys.

Just wondering if anyone knows if DSS is able to recognise if an image is inverted compared to another? Meaning if I do an image run pre meridian flip then realign post flip and do another run, will DSS recognise that the images are the same, but half are inverted? Will it make any difference if I rotate them so that all images are orientated the same?

The obvious work around would be to rotate the camera but then that means taking additional flats. Meridian flips are traumatic enough with having to take flats as well.


The reason I ask is that over the new year I took about 12 hours of data on M42m over three nights. I only got around to stacking them all last night but DSS only stacked 4.5 hours worth. It’s possible that the seeing was bad enough to reject some data but I highly doubt that 8hrs of data was rejected because DSS deemed it inferior.


Thanks for any replies.

Thanks

[mithrandir (Andrew)]

From what I've read you should process the pre and post images separately, then rotate and finally stack. This is especially important with OSC where rotating before debayer screws up the colour.

[White Rabbit]

Thanks for that, if that is in fact the case, I have an issue because I've already rotated them to the same orientation.

Does anyone know a way telling which images (raw) have been rotated?

Thanks