GRAS Image M20

[renormalised (Carl)]

I was getting bored sitting around not being able to do any observing, as the sky up here has been woeful for ages, so I decided to give the GRAS a bit of a shot. See what it was like...so I signed up for the trial run using GRAS-013 and gave it a go. Took some pics of M20.

The GRAS-013 is a Tak Sky 90 (90mm) APO, FL of 416mm, F/4.6 scope. FoV was 135' x 169'. The camera was a SBIG ST-2000XMC, single shot colour rig. Exposure time of 600secs (10 minutes). Original photo was preprocessed before I received it (darks, etc). When I got the original off the press, so to speak, it looked like it was being imaged through fog and there was a lot of noise in the pic. Looked pretty sad. So I did what I could to improve it (given what I had to work with, being preprocessed)... performed colour balance and adjusted the curves (played around mostly with the midtones and shadows). The results look quite a bit better and even though I might be able to do some more on the image, I'm happy with what I've got.

I've posted the original and the cleaned up pic to show you the difference and what quality of pics are coming from the straight downloads from the scope.

If anyone wants to play around with the pics (jase, give them a whirl), feel free to do so.

[jase (Jason)]

Great to see you getting into some remote imaging Carl. Unfortunately, there isn't much you can do with the GRAS13 data. You really need to get access to their other systems to get the un-calibrated FITS and work from there. If you've worked with FITS before and/or individual R,G,B files - its not a major issue. There is certainly a bit more work involved than an OSC set up. Its near impossible to work miracles on what you've got. I hope to see more from you soon.

Cheers

[renormalised (Carl)]

Originally Posted by jase

Great to see you getting into some remote imaging Carl. Unfortunately, there isn't much you can do with the GRAS13 data. You really need to get access to their other systems to get the un-calibrated FITS and work from there. If you've worked with FITS before and/or individual R,G,B files - its not a major issue. There is certainly a bit more work involved than an OSC set up. Its near impossible to work miracles on what you've got. I hope to see more from you soon.

Cheers

Yes I know, that's the downside to one shot colour cameras. I'd much rather work with the mono's any day. FITS images....seen all to many of them. Them and TIFF's. When you've done a lot of remote sensing/GIS work before, you get to see them nearly every day. Plenty of LANDSAT and Spot satellite data!!!. Plus a fair bit of astronomical work as well.

Actually, I don't expect to work miracles even on FITS data....it's just enough to get what you need or want out of them half the time

[Robert_T]

Looks good to me your re-process in particular.

SO how's this GRAS thing work.. you pay someone (observatory) to do an image for you?

[renormalised (Carl)]

Thanks Rob. The scopes are fully automated, so you tell the scope what to point at, what filters to use, how long to run the exposures for....etc, etc.

With scopes like GRAS-013, it's a one shot camera, so there's no filters and such to deal with. You just tell the scope where to point and shoot, then sit back and watch.

[AlexN]

Looks much the same as my G-13 M20 pic

[renormalised (Carl)]

It should, Alex