IC 1396 - 180mm, f/3.5

[AndyUK]

Having been away from my desk yesterday, I got back relatively late and tired. Although I need to get a lot more panes on a mosaic I'm trying to get of this with the MN190, I wasn't sure I was going to be able to get enough subs without falling asleep half way through, so decided to have a go at guiding my Sigma 180 f/3.5 lens.

The moon didn't really help but I was able to get 52x4 mins exposures before dawn stopped play. I first tried my homemade Y mask to focus on Arcturus (hmm - A remake required here ), but then discovered that my 80mm B mask works anyway . However, I found that I couldn't see the pattern well enough even at 10x zoom so had to tweak the focus after each trial shot until I thought I'd got the best I could get (with hindsight, I should have tried using APT ).

The second issue I had was that when I slewed to IC1396, there was no star in the FOV that showed on the liveview screen - Although I took a 2min exp at ISO 3200, it was so bleached out with moonglow I could only identify one star and had no idea in which direction the nebula lay from it, so framing was totally pot luck!

This isn't quite in focus (so it's best looked at either from the thumbnail or with eyes half closed from way across the room!), but I thought I'd share it so that anyone else who has a lens around this focal length can see the FOV it gives on IC 1396.

(Oh, by the way, I didn't fall asleep after all... I could have gone for a 4th pane after all!)

[Psychobilly]

Interesting.. I find these widefields of objects against the MW benefit from a tad of star reduction...

[msinclairinork]

Well done Andy! That's impressive!

Michael

[AndyUK]

Thanks both - I do wish I'd been able to get better focus though... . I think APT is probably the first stop and then, if necessary, I can maybe look into that TS lens focusing device...

Peter - Here's my effort at star reduction (Noel's actions - I think I used it 4 times)

[darkside]

very nice andy, the second edit looks loads better mate

[steppenwolf]

I love these widefields but too many stars (!!) can be an issue especially as camera lenses don't capture them particularly well and they can look a little 'mushy' - your star reduced version has made a worthwhile difference.

[AndyUK]

... especially as camera lenses don't capture them particularly well and they can look a little 'mushy'

... Obviously also not helped by poor focus...! If I can get that sorted, this has given me the start of an idea... . Thanks both...

[ollypenrice]

Great idea. I must have a pot at this with the 200 lens because the ionized part is a tight fit on my Tak image at 328mm and what you show so interestingly here is that the dark nebulae extend well beyond the ionization. Context is so important in images.

Olly

[Psychobilly]

Nicely reworked Andy...

The focus looks close enough for focus magic to do it's stuff - I tried it on the low res jpeg - becuse of the dense starfield it really needs to be applied to the hires though..

Peter...

[ollypenrice]

If you have Noels Actions try selecting the stars and then going Filter, Other, Minimum. Apply it and then back off the effect in Edit, Fade Minimum. I found that quite good on my Cone to Rosette shot.

Olly

[AndyUK]

Hi Olly - Thanks... That was the bit that surprised me too. Until I started on that 40D/MN190 mosaic project, I had no real idea how big this entire object was, and this exercise with this lens was really also partially to help with that mosaic as I was hoping it might provide me with a sort of map.

Although I know I still have that other ongoing mosaic, I'm wondering what a 200mm lens mosaic might pick up around this - By a rough calculation, this 180mm lens gives a FOV of roughly 7x4.5 degrees (I think), and I'm now intrigued how much further out the dark nebulae might go...

Also thanks for the Noels actions tip - That's a bit of a software I DO have . Now that I'm getting a tiny bit more "au fait" with PS, I'm not using is as much as I used to, but there's still some favourites in there (and maybe I'll start using some others when I get the 314L running...)

Peter - If you don't mind pm'ing me your email address, can I invite you to my dropbox to download the embedded DSS output tif file of this to play with? I'd be very interested to see what someone who's used to dealing with these types of widefield images (with the necessary software) can do, but as you say it helps having the hi-res image to start with (the jpg's posted here I had to reduce to level 6)

[luisevan]

Its full of stars Very nice shot.