Mosaics

[Mav359]

Hi guys

When you do mosaics do you just take multiple series of subs on an object, stack them and bias/dark/flat subtract and then stitch them together before processing?

Cheers

[Bizibilder]

Usually process each pane first then stitch together last of all. The trick is to get all the panes as alike as possible, in terms of background colour/brightness.

[Mav359]

Ah see I thought you could avoid having to make sure you process them the same by stitching them together after stacking but before processing

Cheers

[wiruna]

It's likely that there may be intrinsic differences in the different panels due to gradients, changes in sky transparency and so on. If you stitch them together before processing these differences will show up. I should also mention that MaximDL has a nice mosaic stitching routine that will match the different panels if they are not too different.

Geoff

[Mav359]

Thanks guys

I'll check Maxim's stiching out. Cheers Geoff

[Psychobilly]

If Deep space mosaics really become your thing then you might want to have a look at Aurora Imaging's Registar... (not to be confused with Registrax) ...

RegiStar Home Page

The other "trick" it offers is the control it gives when combining images from widely differnet optical setups is Olly is a bit of a Master at using this technique...

Peter...

[Mav359]

Cheers Peter

I'll have a look at registar

I haven't even had a go yet there are other thing's i need to be better at first but i like the idea, it really appeals to me and i'm looking forward to trying.

Right now the best i can manage is a compete mosaic of the cloud above my head

[Catanonia]

if you have the dosh, PixInsight is probably the best tool out there since November 2011 (probably before, I can't remember when the gradient mosiac update was releasesed). You can acurately stitch images together before stretching them and gives the best results.

here is a video I made on it

http://dl.dropbox.com/u/10801850/Astro%20Pictures/Videos/PI%20Gradient%20Merge%20Mosaic.mp4