Deep SMC with 100ED

[avandonk]

I used up a whole clear night to get this image. Twelve fifteen minute exposures with in camera noise reduction on takes just over six hours. I am sure it was worth it.
Details
Canon 5DH, Orion 100ED with Astro Physics focal reducer so 640mm at F6.4, 12X15 min at ISO 400, corrected for flats with ImagesPlus, stacked with RegiStar, digitally developed with IP, levels and curves in PS.

Large image 1.9MB
http://members.optusnet.com.au/~trlee8/SMC_100ED.jpg

here is the SMC taken at 300mm from a previous post
3MB
http://users.bigpond.net.au/avandonk/SMC_m.jpg

Bert

[h0ughy]

So how much difference would there have been if you did it in ISO 800? Very nice work Bert. CS

[EzyStyles]

never knew you had an ed100 bert. great images.

[Lee]

Great shot - you really need to look at the full res one to really appreciate it though....
Heaps of DSO's in that DSO isn't there! :D

[avandonk]

hOughy the signal to noise or dynamic range decreases as you use higher ISO. You get an image quicker but the noise is far worse at high ISO. If you look carefully there are wall to wall resolved dim stars in the background, these would be lost in the noise at higher ISO than 400. It is a bit like life you have to make compromises in this case between speed (sensitivity) and quality (signal to noise). Its like what you do at a seance, strike a happy medium.:lol:
The other reason I went for it was that the ambient temperature was close to zero over the imaging period. This further enhanced the signal to noise.:)

Bert

[tornado33]

Great work Bert. 180 mins, thats a marathon effort. Yes, if you can go for exposures of 5 minutes or more, low ISO's seem to be the go. I shoot iso 200 when imaging without the UHCS filter, any higher and the sky is too bright, though I tend to stick to higher iso's when using the filters on the 10 inch.
Scott

[Striker]

Thats a great effort Berty Beetle...you sure have some serious exposure time.