M31 - binned and unbinned

[Helen]

I'm slowly working out the uses for the different tools I have at my disposal...

Last night's experiment was binning.

I'm desperate to get an image of Andromeda, but I know its very hard. I thought I'd try binning to see what happened (Fastar is the next thing to try)

So here are the results of my binning experiment.

All taken with usual setup NS8, Alt Az, 3.3FR, IR blocker, ATiK 16ic some clouds passing over, occassional breeze, cold (but a nice night to be out!)

Firstly unbinned 30sec subs, 27 out of 30 stacked in DSS, and processed using levels, curves, and Noel's local contrast in Elements

Secondly binned 2x2 combination of 20 and 30sec subs, total 10 m stacked in DSS, cropped to remove rotation artifacts, and processed using levels, curves, and Noel's local contrast in Elements

Its hard to get detail out of these without burning out the core! But I've learnt a bit about the balance between sensitivity and resolution (I much prefer the smaller binned version )

Any guidance on avoiding burnout, and getting subtle detail, in particular would be very welcome!

Thanks

Helen

[CELESCOPE]

Hi Helen old Rog again, lol . yes well 2x2 binning is fine i use it for presenting on here , for printed work we really need the unbinned, for you at the moment 2x2 binning is the way to go with short exposures, M31 would need at least 60 sec subs to get that outer dust lane/s, although with that set up you are on you will only get the centre core and a small part of the outer ,the core is safe from burn out with the Atik,, unbinned a 5 min exposure would take the core out and no way of getting it back , 60 secs will be the best, now i can only comment on Maxim , maybe Martin or KK can help , but i use DDP using it set to custom and using a % of about 5% no more ,click ok on that , this will give you a grossly over exposed centre core , but now come the trick , using the stretch box u can reduce that core to pinpoint if you want , or as i do leave a small white blob , but then use the blur just a tad in Photoshop to soften it,, but your core is,nt to bad.

Rog

example, ED80 AT F5 GIVES YOU THIS

[GazOC]

Yep, the smaller version looks better to me as as well. Think theres a typo in the title though, its M31.

[Helen]

Yep, the smaller version looks better to me as as well. Think theres a typo in the title though, its M31.

Arrgh - title changed (got an m33 on my computer that's much too bad to post yet!)

[Helen]

Thanks Rog that's a great picture for me to aspire to!. Need to try with Fastar and with the ZS66 (balancing is getting closer... )

Helen

[centroid]

Your imaging skills are coming along in 'leaps and bounds' Helen

A very good effort indeed, and now that Roger explained the 'trickery' needed to reduce the core, it can only get better.

'Keep em' coming!!.

Dave

[zhgutas]

I simply don't have a clue what wizardry you are talking about here (binned, unbinned and other stuff), but this is a very nice Princess you've got Helen Mine looked as a blob only

Marius

[Helen]

Thanks Dave and Marius!

Marius - I'm only showing off because I now know what binning means (it means grouping pixels together to get a smaller number of super-senstive pixels) A few weeks ago I didn't have a clue either!! Its like learning a foreign language this!! The next bit of learning is to know when to use binning appropraitely But I'm pleased with the image, my last one was a blob too!

Helen

[MartinB]

Well done on that one helen. You've got some good detail on the fine dust lanes which run around the core. It is a very big target and extends way beyond the field of view. M33 should be worth a go soon

[SteveL]

I found this tip about layer masks a while back for M42, and thought it might help you with M31

http://www.astropix.com/HTML/J_DIGIT/LAYMASK.HTM

[Helen]

Thanks Steve, I'll have a look.

Thanks Martin, I grinned alot when the detail started to emerge - I think its the first time I've got galaxy detail

I've had one go at M33, but gave up on the processing... I've now re-read your levels and curves primer and am working through Chapter 8 of Ron, so will give the data another go then. It was fairly low for me, so I may need to give it another go with more exposures too... watch this space

Helen