Sadr and the Crescent Nebula

[rocketandroll]

So.... last night looked set to be clear and I needed to work late at my workshop anyway so I planned to run a shortish imaging session on a new target...

Problem 1: Despite it being a hot clear day, there was a strange mist hanging around when I got there... luckily it didn't seem too deep though and it only seemed to be a problem down towards the horizon.

Problem 2: Some numpty has attached a security light to the side of the workshop building which is on ALL night. Thankfully it wasn't directly in line with what I wanted to image, but it wasn't helping.

Anyway... despite these issues... I got the mount set up and (quickly) polar aligned... then sent the go-to to Sadr (Gamma Cygni), which it found easily.

Once I'd spent half an hour trying to get the focus dead on on my 200mm Canon lens (can't wait to get the damn microfocuser rings I have on order!!!) using 30 second subs, I set it to do a 90 second sub...

It's always a lovely feeling when that first long sub appears on the screen and you can see all the nebulosity suddenly appear :-)

Anyway, my plan was to get the nebulosity around Sadr as well as the crescent nebula in one frame. Unfortunately my current camera mount doesn't allow the DSLR to rotate in relation to the mount so I am currently stuck with whatever angle it ends up at depending on what it's pointing at. Thankfully, knowing roughly where the crescent was in relation to Sadr I slewed the mount a little and did another exposure and there it was....

So, I set a run going that should have been about 1hr 20 mins of data at f3.2, but I got called back home to deal with unwell baby after just 45 mins.

In the end this is just 40mins of data with just 4 darks (but 20 flats) applied. I'm fairly happy with what I've got out of such a short run and, although it's not perfect, the focus is a lot better than the IC1396 I did last month. Colour is a problem, but again, I'm hoping more data will help that.

I think my plan is to re-do this target in a month or so once I A: have guiding and can do 5 mins or so subs on it, B: have the micro-focusser ring so can get focus much better and C: have longer nights so I can grab 2hrs in one sitting.

Anyway, despite all this... I'm moderately happy with the result.

So: this is 40mins of data in 90 second subs at ISO 800 and f3.2 using my moddel Eos 350D and the Canon f2.8 200mm prime lens, mounted on a HEQ-5 Pro, unguided.

Ben

[Psychobilly]

Nice shot...

The other neb is more commonly know as the Crescent Nebula NGC6888.. the Jellyfish Nebula IC 443 is close to the Monkeyhead Nebula NGC 2174 on the Orion/Gemini border..

Peter...

[rocketandroll]

Ah, sorry.... though they were one and the same thing.... doh :-)

Will see if I can edit it accordingly.

Ben

[rocketandroll]

Done it.... thanks for the heads up on my stupidity :-)

[AndyUK]

That's a superb wideview around Sadr - And by the look of Sadr itself, your focus looks pretty much spot on... Well done! It certainly puts the Crescent Nebula into a lot of context within that huge starfield...

However, I certainly empathise how tricky it is focusing DSLR lenses - I don't think I've ever really managed it and the images always come out mushy... Are you buying that microfocuser from TS?

[rocketandroll]

Hey Andy...

Yeah, the TS microfocuser rings are currently the ONLY item on my birthday wish list for a couple of weeks from now :-) I have forwarded my mrs the link to buy the right diameter and told her it may take a while to get it over from Germany :-)

Focus on this is definitely better than on the IC1396 I did a few weeks back, that was obviously blurred.

It's still not quite perfect though... trouble is, it's hard to see it in context on a tiny screen on the back of the camera, there's a range where, without comparison shots side by side, you could think it was in focus, but it isn't quite when you zoom in... stars look tiny and well defined, but then you take another shot with it 1/10th of a degree to the left and they're a teensy bit smaller... it's so hard to tell.

I need a way to drag images off the camera and view them on a laptop immediately to check... might break my golden rule and hook the 350D up to the laptop next time I try it... have a horrible feeling my laptop's on Win 7 though, and I've seen the thread on that subject :-)

Ah well... for now this isn't bad... just need to get guiding (Synguider arrived today) and work out a new way to mount the camera so I can rotate it and get better control of orientation.

SO MUCH WORK!!! :-)

Looking forward to longer nights and having a proper crack at some of these things though... it's always encouraging to see something ok out of just 45mins work.

Ben

[rocketandroll]

Ok, tweaked it a little more to remove the gradient from the right hand edge and bring the nebula out a little more.

My laptop screen is REALLY bright so this may now look a lot darker than the last one?

Anyway, possibly a slight improvement.

Ben

[Psychobilly]

Have a look at the Jessops Ball and Socket heads BH-40... the latest ones are a huge improvement over their previous offerings...

http://www.jessops.com/online.store/products/77744/show.html

I prefer Manfrotos having a selection of different head the biggest being the 488RC2 the 496RC2 is the one I use the most...

Peter...

[AndyUK]

Hi Ben

I need a way to drag images off the camera and view them on a laptop immediately to check... might break my golden rule and hook the 350D up to the laptop next time I try it... have a horrible feeling my laptop's on Win 7 though, and I've seen the thread on that subject :-)

I too dragged my heels on "going attached"... I guess when you say Win 7 you mean 64 bit? If it's 32 bit, you should be fine (unless Canon have decided to stop making 350D drivers?). You've just reminded me though, I have an old XP laptop knocking around somewhere - It would be fine for "powered" use but the battery only gave about 45 mins or so...