NGC 1760 in HaSIIRGB

[Andy01]

Hi folks,

2nd attempt at this slightly uncommon target and my first attempt at blending NB & RGB with my new QSI wsg8 mono camera.

I was battling constant clouds over three nights and so this is still needing yet more Ha data (can you ever have enough?)

About a dozen 10 min subs of Ha & SII binx1 & 6 each of RGB binx2

Some issues with maintaining focus & registration during meridian flips and my flattener still needs some adjustment. Wish there was a plate solving app for the mac!

Anyway, this is the best I can manage from the data so far - probably overcooked it a bit, but I hope you like it :)

High res here - http://www.astrobin.com/138906/ it's a small target in my FOV so don't expect too much!

Constructive criticism most welcome - I'm still learning mono processing :)

Andy

[gregbradley]

That's really very nice Andy.

Its great these nebulas around the LMC are being imaged so much in the last year. You never saw images of these nebs just a few years ago.

Greg.

[lazjen]

It's an interesting mix. How did you map the data to the colour channels (what proportion, etc)?

Also, for plate solving, you might like to check out getting astrometry.net working locally on your Mac: http://astrometry.net/use.html

[Stevec35]

Looks pretty good to me Andy

Cheers

Steve

[Andy01]

Thanks very much Greg, really appreciate your taking the time to comment. :thumbsup: I think I'll keep nosing about in the LMC & SMC for more of these interesting and rarely imaged targets.



Thanks Lazjen - I'll have a look at Astrometry.net and see if I can make it work. :thumbsup:

Colour selection was interesting - after many variations, I eventually settled on this combination where the data was mapped as follows ...

Ha - Red,
Green - Green
Blue - Blue
SII - Hue/saturation PS285

I've attached a snapshot of the Layers in PS. The stars are a separate RGB layer over the top.




Thanks very much Steve :)

[Geoff45]

Very nice shot Andy. I don't think it's overcooked at all. As far as constructive criticism goes, there may be some focuser tilt. The stars on the right are nice and round, while they get a bit eggy on the left, especially near the bottom left.
Geoff

[Andy01]

Thanks Geoff, I appreciate your feedback :thumbsup:

- Focuser tilt eh? I was originally thinking maybe it was the flattener needing adjustment, but it could well be the focuser - any suggestions on how to rectify that, other tan getting a Moonlite or Feathertouch?

Cheers

Andy

[tilbrook@rbe.ne]

That's a nice NGC 1760 Andy!:thumbsup:

Cheers,

Justin.

[SimmoW]

A really violent image that Andy, in a good way! Congrats on a pretty difficult process from what I can see.

I loaded up the Astrobin version, and can see a weird patchwork/grid pattern all over the image, like a flywire screen. What's that? Or does my monitor need turfing?!

[Geoff45]

I would have thought that if it was the flattener, all the corners would be equally affected. If it is focuser tilt then you could try carefully focusing a star on one side of the field (using a bahtinov mask for example), then focusing a star on the opposite side. If these are different (and it won't be easy to get it accurate) then the way you have to move the focuser will tell you which way things are tilted. Then follows trial and error shimming. It may also be slack in the focuser, so tightening it up may work.
Another thing to try is to put a laser collimator in the drawtube and see if the spot hits the centre of the object glass.
Good luck!
Geoff

[Andy01]

Thanks Simmo - the grid showed up in an earlier version too - can only think it may be in one of the flats or a preprocessing misalignment thing perhaps. Honestly not sure. :shrug:



Aha, ok, thanks for the tip Geoff, I'll give it a go as soon as these clouds nick off! So much still to learn...

Cheers

Andy