Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: Daniel on Jan 18, 2010, 21:43:14

Title: MonkeyHead Nebula 32x 180s ISO 160
Post by: Daniel on Jan 18, 2010, 21:43:14
Hi All, managed to get out for the first time in ages last night and grabbed just over an hour and a half on the monkeyhead nebula, stars went a little squiffy, so will have to do a re-stack soon with only the best subs.

Anyway, here it is, full frame and closeup

Daniel
:O)


(http://farm3.static.flickr.com/2725/4285444345_476e66281b_o.jpg)


(http://farm5.static.flickr.com/4053/4285444337_634ccb925b_o.jpg)


Title: Re: MonkeyHead Nebula 32x 180s ISO 160
Post by: RobertM on Jan 18, 2010, 22:48:50
Squiffy stars or not, that's a lovely clean noise free image.  I think longer subs might have brought out more nebulous detail but you've done really well, especially from Thamesmead - still can't quite believe what you manage to capture from there !!!

Robert
Title: Re: MonkeyHead Nebula 32x 180s ISO 160
Post by: MarkS on Jan 19, 2010, 05:49:32

Wow Daniel, you've gone and done it again - capturing the impossible from your light polluted location.  I love the colour.  Was this done with the CLS filter?

Mark
Title: Re: MonkeyHead Nebula 32x 180s ISO 160
Post by: Fay on Jan 19, 2010, 08:45:00
You do do well, Daniel, cannot believe you get all these images from your garden!!!!!!!
Title: Re: MonkeyHead Nebula 32x 180s ISO 160
Post by: Daniel on Jan 19, 2010, 09:34:07
Thanks guy's, was quite happy with the smoothness of this one myself, just wish I'd sorted the collimation out a little better.

Mark, Yes, this was using the CLS filter. shall post shooting info a bit later on, uploaded this in a bit of a rush


Daniel
:O)
Title: Re: MonkeyHead Nebula 32x 180s ISO 160
Post by: MarkS on Jan 19, 2010, 10:07:57

Daniel,

Does your hyperstar remain permanently attached to the scope?
Do you find you have to collimate for every imaging session?

Mark
Title: Re: MonkeyHead Nebula 32x 180s ISO 160
Post by: Daniel on Jan 19, 2010, 11:40:53
Hi Mark, unfortunately I don't have it permanently attached so I have to re-collimate every time I set up, can be a nightmare, sometimes can take 10 minutes, sometimes an hour! usually bad seeing will make collimating a lot harder.

Daniel
:O)
Title: Re: MonkeyHead Nebula 32x 180s ISO 160
Post by: MarkS on Jan 19, 2010, 12:54:36
Quote from: Daniel
I have to re-collimate every time I set up,

Wow, I guess you're very patient!  And probably an expert at collimation by now.

Does collimating the Hyperstar require a special tool or do you rely on the symmetry of de-focused stars?  I now check the collimation of my C11 every time I use it but I can frequently get away without actually re-collimating.  I use defocused stars.

Mark
Title: Re: MonkeyHead Nebula 32x 180s ISO 160
Post by: Daniel on Jan 19, 2010, 13:05:26
I use the de-focussed star method to collimate the hyperstar (not easy when you can see the shape of the camera obscuring the shape of the secondary) Once I've done that i normally focus and then do spot adjustments on the collimation again to clean up the edges, as you can see, It didn't go too well this time!

Daniel
:O)
Title: Re: MonkeyHead Nebula 32x 180s ISO 160
Post by: Mac on Jan 19, 2010, 14:03:21
QuoteI use the de-focussed star method to collimate the hyperstar :roll:
I've used that method for the LX200, but only recently (last year) found out that if you defocus the star too much, you cant actually get good collimation.
as the circle actually appears to be in the middle, (unless its very very off).
I used to make my defocused star quite large. half the image.

Just one question.

With the hyperstar, is there any limit as to how far you can tilt the tube?
only with the weight of the camera being held there by the fittings on the front glass, surly that would put a huge strain on the glass when imaging towards the
horizon.

Mac.

Ps love the image, you can defiantly see why is called the monkey head
Title: Re: MonkeyHead Nebula 32x 180s ISO 160
Post by: Daniel on Jan 19, 2010, 14:15:06
Hi Mac, The hyperstar is pretty heavy but the glass of the C14 seems to hold well, I've imaged all the way down to sagittarius with no problems.

The de-focussed star method is great for getting wrough collimation, but you definitely need to do the same on a focussed star taking 1-2 second images to get it just right.

Daniel
:O)
Title: Re: MonkeyHead Nebula 32x 180s ISO 160
Post by: Daniel on Jan 19, 2010, 17:32:22
Just thought I'd post imaging Details....


Imaging Scope = C14 with Hyperstar III
Camera = Canon 40D (Modded)
Ambient Temperature = 3 Degrees Celcius
Seeing = Moderate
Filters Used = CLS
Date Taken = 17/01/10     
Light Frames = 32x180s ISO 160
Dark Frames = 9x180s ISO 160
Bias  = 100x1/8000s ISO

Title: Re: MonkeyHead Nebula 32x 180s ISO 160
Post by: Rocket Pooch on Jan 19, 2010, 18:50:17
I really like this the noise is low and its kinda hanging there in space.

Title: Re: MonkeyHead Nebula 32x 180s ISO 160
Post by: Ian on Jan 20, 2010, 09:17:26
Quote from: Space Dog on Jan 19, 2010, 18:50:17
its kinda hanging there in space.

as opposed to?  ;) :cheesy:
Title: Re: MonkeyHead Nebula 32x 180s ISO 160
Post by: Mac on Jan 20, 2010, 13:32:12
Quoteits kinda hanging there in space.

as opposed to?    ;) :cheesy:

being nailed there

(http://www.macrhon.co.uk/website/oasphotos/nailed.gif)

:cheesy:

Mac.
Title: Re: MonkeyHead Nebula 32x 180s ISO 160
Post by: JohnP on Jan 23, 2010, 21:41:34
Daniel, Very nice - extremely smooth (looks almost too smooth - did you use a noise reduction algorithm in your processing?)  - Perhaps a 'tad' dark for my liking but all in all an excellent image AGAIN !!!!!

Good Job,  John