Stacking, darks, flats - where to start???

[MortonH]

Have just bought Dannat's Polarie and am hoping to do some simple wide field imaging with it. I have read a little bit about stacking multiple images but have never seen or used any of the programs available. Nor do I have much of a clue about darks, flats, etc (I only know they exist cos I see them mentioned a lot in the Images forums).

I have two questions to get me started:


Recommendations for inexpensive stacking programs for Mac, and
A resource that will explain the basic techniques so that I don't spend hours scouring the web.


Any help would be appreciated.

Thanks

Morton

[Poita]

Use nebulosity on the mac as your starting point, there are good tutorials on the site and it is easy to use and gets good results.

The Nebulosity website has the basic techniques all laid out in a tutorial.

http://www.stark-labs.com/help/nebulositytutorials/tutorials.html

and one for Canon owners:
http://www.covingtoninnovations.com/dslr/nebulosity/tutorial.pdf

[MortonH]

Thanks, Peter. Nebulosity was likely to be my starting point in the absence of any other recommendations, so I'll give it a go.

[gbeal]

Yep, valid advice, and if you are going that way, use PHD as well, same "author", both are wonderful, and native on the Mac too.
Gary
PS. just read, "Polarie", so scrub PHD, but eventually the bug will grab you, believe me.

[MortonH]

Spent a bit of time reading the links above. Seems quite complicated. I think I preferred the old days with a single 5-minute exposure on film!

[Merlin66]

Sorry I don't know about mac...
but if you go over to windows, AstroArt as a "processing pipeline" that does all the dark/ flats/ bias work for you........

[gbeal]

I feel for you Mort, I recall the same trepidation when I started, but just jump in, you can't fail. And if you do, post what it looks like and we can help.
Really, I suggest you just shoot as many as you feel you need, then some more to boot. Use either Nebulosity (it has a free trial) or some other stacker, and see what you get. DeepSkyStacker is good, and as Ken said AstroArt is too, better in fact. BUT........ they are both Windows based.
Try nebulosity first.
Forget darks, flats, and bias frames, just shoot lights and stack them. Report back with what you get and we can go from there.
I'll wager there will be someone in your area that can/will help you, but failing that blunder on and ask when you get a result, any result.
Gary

[MortonH]

Thanks, Gary. After I started reading the tutorials on Stark Labs I realised I was trying to learn the processing techniques without even knowing all the capture techniques in the first place! But if it's worth stacking without all the darks and flats then I'll try that. Heck, my biggest challenge may be getting round stars. I've never polar aligned in my life, even in my native Scotland where we have a pole star!

[scopemankit]

Try Deep Sky Stacker. it's free and quite effective!

[bojan]

I would agree with Chris (However, DSS is windows software.. and Morton wants something that runs on Mac)
Have a look at this comment: http://tech.groups.yahoo.com/group/FLI_Imaging_Systems/message/4537

Spending hours learning the process can't be avoided - even if the process is automated, you still need to know what you are doing (otherwise, what's the point? )

[alistairsam]

Hi,
You should be able to run DSS in Parallels or other VM software on a Mac, although it would be slower than a native Mac app.

In terms of processing or calibrating widefields, I think flats would make a significant difference in removing gradients.
Darks help with reducing noise, but you'd need to dither to be sufficiently effective. all depends on your exposure length and the operating temperature as that governs the amount of noise present.

you could take flats at twilight or dawn or even using an LCD monitor.
I think Al has written a software that's available here in the Projects section.
There's also this article http://www.iceinspace.com.au/63-211-0-0-1-0.html
Cheers