Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: Fay on Mar 18, 2010, 13:29:42

Title: The Foxfur/Cone nebulae Christmas Tree Cluster NGC2264
Post by: Fay on Mar 18, 2010, 13:29:42
Taken At DSC Blacklands, I am not too happy with this, needed a lot more subs, looks noisy. 25x300, flats included,  Modified Canon 350D, 0.8 dedicated flattener/ ED80
It was a clear sky. most of the time, but had to keep stopping because of clouds & ended up imaging in about 5 sessions during the evening. When I lok at ther versions of this nebula, they always look so dramatic, perhaps mine is pure!!!!!!!!

(http://farm5.static.flickr.com/4068/4443299498_e189571111_b.jpg)
Title: Re: The Foxfur/Cone nebulae Christmas Tree Cluster NGC2264
Post by: MarkS on Mar 18, 2010, 14:30:56

Fay,

That's not bad at all.  It was not taken under ideal conditions since it transited around 7pm and astronomical dark began at 8pm - so you were clearly imaging it as it descended into the murk.

A CLS filter would have helped to bring it out of the murk but would also have created a colour cast - but since the H-alpha is the main subject of the image, I think it would have been worth it.

How do you shrink your image down to size?  If your software allows you to do so by binning pixels together, this will reduce the noise quite substantially - it's a trick that I frequently use.

Mark
Title: Re: The Foxfur/Cone nebulae Christmas Tree Cluster NGC2264
Post by: Fay on Mar 18, 2010, 14:37:09
Hi Mark, I had a clip in cls filter. Tell me about the little binning trick please. I just crop it in PS
Title: Re: The Foxfur/Cone nebulae Christmas Tree Cluster NGC2264
Post by: Fay on Mar 18, 2010, 14:48:20
Mark, is it, you bring image up to 200%, in PS, then reduce down to 50%?
Title: Re: The Foxfur/Cone nebulae Christmas Tree Cluster NGC2264
Post by: MarkS on Mar 18, 2010, 15:22:15

I do 2x2 binning in IRIS (of course!)

It might be possible in Photoshop - does anyone else know?
Title: Re: The Foxfur/Cone nebulae Christmas Tree Cluster NGC2264
Post by: Mac on Mar 18, 2010, 16:02:27
QuoteIt might be possible in Photoshop - does anyone else know?

Nope, Photoshop will only re sample and crop the image, It doesn't do true binning in the astronomical scene.
Title: Re: The Foxfur/Cone nebulae Christmas Tree Cluster NGC2264
Post by: JohnP on Mar 18, 2010, 16:03:08
No can't do in PS - you can do in aip4win - sure you can do it in maxim as well Fay - John
Title: Re: The Foxfur/Cone nebulae Christmas Tree Cluster NGC2264
Post by: Fay on Mar 18, 2010, 16:08:11
So bring up to 200 & then down again? % or pixels?
Title: Re: The Foxfur/Cone nebulae Christmas Tree Cluster NGC2264
Post by: JohnP on Mar 18, 2010, 16:19:07
Fay the image you have displayed above is obviously a lot smaller than the full size (unless you have just cropped a small part of the full frame). Rather than reduce image size in Pshop you can put image in aip4win or maxim & then bin 2X2 - if you are using the full frame of your eos it will still be a large image.

Out of interest the full size of my atik16ic is only 640X480 pixels so what I do is increase image by either 200 or 400% in Pshop prior to processing & then as a final step bin in aip4win 2X2
Title: Re: The Foxfur/Cone nebulae Christmas Tree Cluster NGC2264
Post by: Fay on Mar 18, 2010, 18:03:54
must be doing it wrong.

up to 200 in PS then opened in MAxim 2x2. looked wrong. Oh just noticed "prior to processing"