Orion Constellation with Nebulae

[MarkS]

This is very much a work in progress - 5 x 5min shots with Canon + 50mm lens at F1.8, piggybacking on the scope.  I need to shoot a lot more data and I'm still having problems with a flat field (rubbish still in the corners).

However, Barnard's Loop is just beginning to appear to the left despite the lack of H-alpha sensitivity.  It was taken last weekend down at Dungeness where the skies are very dark.

http://gallery.orpington-astronomy.org.uk/albums/userpics/10046/oriondss4.jpg

Suggestions for processing this better are welcome.

[Rick]

I love wide-field shots like this, especially when they shart showing up the large-scale nebulosity. What processing have you applied so far?

[Tom C]

Nice one! I too tried a widefield shot of the bottom half of orion earlier tonight with my Canon. I bought a tripod today as well which certainly makes things easier. I actually also wanted to buy the Canon 50mm 1.8 lens, but they didnt have it in stock. So I just used the one that comes with the 400D, the 18-55mm.

Your photo has many many many more stars than mine!! I'm guessing due to the larger aperture and much longer exposure. I was only doing 10sec exposures....I found that any more than that and trailing became apparent ?? I thought I would be ok up until 30sec without trails, but apparently not  . I was at full zoom, would that make a big difference? The max magnification isn't even that high with the stock lens. I'm gunna have a fiddle with it and then maybe post it later if it turns out any good.

Anyway..yours is a nice shot, I reckon with more processing it could be really great. Have you seen Noels Actions for photoshop? I'm considering buying them, only £10 and lots of people seem to reccomend them.

Also take a look at stepphenwolf's Orion widefield, I really like it.


Cheers,
Tom

[Rick]

Have you seen Noels Actions for photoshop? I'm considering buying them, only £10 and lots of people seem to reccomend them.

See this locked thread.

[MarkS]

Tom,

The longer your exposure or the longer the focal length, the more trailing you will get unless you have your camera is on a tracking mount.  It's best to just try it out and see how far you can go before it becomes objectionable.

The reason you are seeing far fewer stars is a combination of your shorter exposure (10sec vs 5min) and your F-ratio (mine was a fast F1.8 ).  Having said that, at F1.8 all sorts of lens aberrations are showing up towards the corners.  I think next time I will shut down the aperture a bit.

Mark

[MarkS]

I never got the opportunity to shoot more data for this.  The Spring skies are arriving (even though the Spring weather isn't) and Orion is already becoming only a memory.

So here is the final image after reprocessing (the misshapen stars are aberrations in the cheap 50mm lens when used at F1.8 ):



The full-size version is here:
http://homepage.ntlworld.com/the_shelleys/Astronomy/orion09022008.jpg

[Fay]

That is very nice Mark.

May I ask what wetsuit you are wearing & what wipers you are using on your camera?????

I have got a DMK mono camera, the same one as Chris, for planetary, moon & guiding. I have been two days sorting it out, seeing how it goes with an an assortment of software. Could not get an AVI to open in Registax, but after 4 hours, I hope it is sorted with a change of CODEX code & a download of version 4 of Registax. It did not work with version 3.

I did get a PL130M camera, which has a large chip  & very high resolution. It kept freezing on different programs so I think that the high resolution would not always be suitable with high frame rates, I could not believe the sizes of the files as well. Anyway sent that one back.

[JohnP]

Nice Mark - Barnards loop is a lot more prominent in the first image (at least on my monitor) but you have done a good job with background gradients in the 2nd.

John

[Fay]

Mark, although you cannot see Barnards Loop in the processed image, I still prefer that one as it is more smooth & subtle.

[MarkS]

Thanks for the comments.  I found a new IRIS function that works great for gradient removal.  Agreeing with Fay, I preferred the overall appearance of the second compared with the original even though Barnard's Loop is fainter.

The coma away from the centre of the image is terrible so I'm now on the lookout for a decent secondhand 35mm or 50mm fast (e.g. F1. prime lens - the one I used was a cheap Canon lens.  With the advent of digital cameras there's a ton of lenses out there that are no longer fully compatible and are going cheap because they can only be used in manual mode.

[JohnP]

I agree as well Mark - 2nd is better. Hope you don't mind but as a quick test I ran it through Noel Carboni's astronomy Tools - Remove Halo's & Increase DSO's... took about 5secs to do...

Not sure if it's better but thought I would post for comparison.

Let me know if you get a good lens as I am interested in getting one also for really wide FOV's..

Cheers,  John

[MarkS]

John,  no of course I don't mind you having a go.  The tool has certainly reduced the halos but has left a rather "washed out" appearance.

If you (or anyone else) wants to play with the original (after stacking, background subtraction and 2x2 binning) it is here:

http://homepage.ntlworld.com/the_shelleys/photos/orion.tif
WARNING - it is a 7MB 1544x1044 16bit image  which I'll delete after a few days.