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Matty P
28-06-2008, 07:47 PM
Now that I have got autoguiding setup and working perfectly. I was able to aquire a couple of exposures of the Eagle Nebula last night. There was no Moon to disturb the imaging session but instead there was some high cloud that cut the imaging session short. :sadeyes:

I was hoping to capture over an hours worth of data so I will definitely add more data when I have the chance.

C8 f/6.3 on EQ6 Pro autoguided with PHD
Canon 450D
7 x 5 minute subs Total = 35mins (Half with ICNR darks and half without. Please don't ask why)
ISO 400
Stacked in DSS and processed in PS CS3

Thanks for looking. :thumbsup:

AlexN
28-06-2008, 08:07 PM
much better than last attempt matty! looking fine!

as with last time, more exposures!! :D

If you can get your tracking accurate enough, go for a deeper look without the focal reducer!

beren
28-06-2008, 08:09 PM
:thumbsup: Very nice image, well done with capture and the guiding at that FL

Matty P
28-06-2008, 10:31 PM
Thanks guys,

I fairly happy with this one but not entirely. I was really hoping to capture more data but bad weather cut it short. However, I am amazed what longer exposures and more of them can do to an image so I am hoping for some clear skies very soon.

:thumbsup:

renormalised
28-06-2008, 11:05 PM
Nicely done:)

gregbradley
29-06-2008, 12:01 AM
Nice shot. Can I ask why you chose ISO400? It seems a bit slow.

I always used the maxium ISO like 1600 or 3200. 400 is taking too long, its like stopping down a F2.0 lens to F5.4.

I have hear dsome say ISO800 gives better depth. Perhaps that is true and but if oyu have darks and flats and bias to subtract then I say go the max and hit it at ISO1600 or 3200.

Just be careful with DSLRs as they often show the stars as all white whereas there should be a variation in colour. I think that is because the star overexpose first so you can go too long. I have heard expose to 1/3rd of a histogram meaning that the hstogram is 1/3rd the screen or expose to the limit of your light pollution as that will hit a ceiling before the object will.

So at a dark site you go longer and higher ISO especially in summer and at a light polluted area you go shorter and more of them and use a light pollution filter.

That's where the 40D comes into its own with the 14 bit converter, stars are more likely to have colour.

Greg.

Ric
29-06-2008, 01:09 AM
Very nice Matty, that cloud was a bugger last night for sure, it cut things short for me as well.

your guiding on this image looks very good. The stars are nice and round and the nebulosity is showing up quite nicely as well.

A fine effort

Matty P
29-06-2008, 10:28 AM
Hi Greg,

I was hoping to go very deep with the expsoures so I dropped the ISO down. I found that a 5 minute expsoure at ISO 800 looked overexposured.



Thanks Ric,

It was disappointing having to pack up in the middle of an imaging session but I was just happy that I was able to capture 35 minutes worth of data before the clouds rolled in.

I thought I was going to have problems with guiding with a long focal length but I am very happy with the results.

RB
29-06-2008, 11:08 AM
A fine result Matty and getting better each time.
I like using ISO 400 or 800, seems like a nice balance between good detail and lower noise.

Matty P
29-06-2008, 04:42 PM
Thanks Andrew, :thumbsup:

I really need to start taking flats to keep improving my images. :)

gregbradley
30-06-2008, 04:27 PM
I see.

Thanks,

Greg.

madtuna
30-06-2008, 05:13 PM
Matty..I've had enough of your supurb images...I want my mount back!!
:D

Matty P
30-06-2008, 05:54 PM
Thanks Steve,

No worries, I will hapilly exchange my EQ6 for your Losmandy G11. :whistle: :lol: