IC 5146 5hrs-5min-43s with a DSLR...

[fwm891]

Hi, With a night of reasonable seeing here on Sun/Mon I added more data and decided to pull all my data on IC5146 (Cocoon) into one image. The image has been stacked in DSS and tweaked in PS CS3. 43 frames were used. No flats, darks or bias frames in this stack.

ISO in most cases was 800 with sub exposure lengths varying from 3 - 10 min.

Scope 8-inch f4 imaging Newtonian, guided with an ST80, QHY5 and PHD. Mounted on NEQ6 Pro, EQMOD.

As this object gets higher and longer nights hopefully I can drop a few of the poorer frames...

Added second image - full frame and re-processed in PS CS3 using the original stack from DSS as a base image...

Francis

[SkyJamie]

Awesome Francis

Jamie

[old_eyes]

A very nice image. Is that dark nebulosity surrounding the core?

old_eyes

[fwm891]

Hi 'Old_Eyes' from North Wales,

Yes it is nebulosity surrounding the core (or line of sight anyway). Have to admit I checked GordonH's image above first just in case I'd over processed mine and caused a dark halo somehow

Francis

[merlinxlm]

What DSLR have you been using to capture image with?

Thanks.

[fwm891]

Hi Merlinxlm,

Canon 450D. Its been home modified with plain glass from Edmunds Optics (York UK) with anti reflection coating on both faces. This gives a full spectrum sensitivity to the CCD. This can be modified using either narrow or standard LP filters to varying degrees, For the above photo I've used a Baader UHC-S filter.

Francis

[GordonH]

Hi Francis

That is looking very good, I have a suggestion that you might like to try if you have photo shop and that is just to back off slightly on the nebula so it isn't quite so bright and then use shadows/highlights adjustment to see if you have caught some of the surrounding dust that surrounds the nebula, this adjustment works very well at this

Best wishes

Gordon

[fwm891]

GordonH - thanks I have photoshop (CS3 Extended) but dont like using the shadows/highlight adjustment as it introduces noise. Much better to use adjustment layers and layer masks.

I tried a method from a recent S&T mag (June 2011 p72) using multiple layers and layer masks for this image - though I did my own mods as one does...

I take your point though and will go back to my layered version and have another play...

[jsigone]

very nice details on this. Is this cropped or full frame?

[fwm891]

Hi jsigone,

It is cropped. When I get round to GordonH's suggestion I will probably work on the full frame at 16 bit. The image above was cropped and reduced to 8 bit before posting.

Francis

[GordonH]

Hi Francis

Regarding the noise, I'm afraid there is only one solution and that is to shoot more data to get a better signal to noise ratio, I used 4 hours in ten minute subs and I found I could use the shadows highlights tool twice without introducing any noise in the image. Unfortunately there is no short cut to this, you just need to get more data in order to use this facility

Best wishes

Gordon

[fwm891]

Added second re-processed image giving the full frame blue/grey mistyness more evident.

As you say GordonH - needs more photons...

Francis