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First mosaic with RASA8 and QHY268 camera

Posted: Sun Aug 09, 2026 4:32 pm
by Jean-Francois
Hello,

I tried yesterday evening some imaging around the Sadr star with my RASA8/QHY268 and H-alpha filter.
I started first with 2x2 mosaic ... and extended it to 2x3.

With FD=2.0 ... 20x 30s short exposures for 10 minutes per stack. Around 70 minutes for all the images.
This afternoon postprocessing and generation of the mosaic. First try with Prism10 software ... but it seems that the mosaic function disappeared.
Then I did it "quick and dirty" mosaic with ICE. But first with a conversion from 16 bit FITS in TIFF images.
The mosaic from ICE (TIFF image) was reopened in Prism for the conversion back in mono FITS. Then reopen in SharpCap.
RASA8_mosaic_1.jpg
RASA8_mosaic_1.jpg (583.57 KiB) Viewed 502 times

Here two small regions ...

RASA8_mosaic_2.jpg
RASA8_mosaic_2.jpg (478.26 KiB) Viewed 502 times
RASA8_mosaic_3.jpg
RASA8_mosaic_3.jpg (560.83 KiB) Viewed 502 times
I did the telescope movement manually ... I will try again with some automated position.

Regards,
Jean-Francois

Re: First mosaic with RASA8 and QHY268 camera

Posted: Mon Aug 10, 2026 10:59 am
by turfpit
Jean-Francois

A good Ha mosaic.

I have used ICE for deep sky mosaics (and lunar). It is easy to use and always gives me seamless stitching (I use a 20% overlap for panels).

If you can capture some OIII data, that would make for an interesting image.

Dave

Re: First mosaic with RASA8 and QHY268 camera

Posted: Tue Aug 11, 2026 12:57 pm
by admin
Hi,

another tip for mosaics is that you can automate with the advanced sequence editor - there is a step 'repeat for each RA/Dec Co-ordinate' which will then perform all your capturing repeatedly for each panel. You should be able to paste the output of something like the 'Telescopius Mosaic Planner' into the list of co-ordinates for that step.

cheers,

Robin