M65/m66, m104

[Starcrazzy]

Hey guys.

Still been plugging away trying to learn this AP business.
These two images are my latest offering. The M65/66 is not well framed as I was too scared to move after Id finally managed to get them in the shot.
About 47 minutes at 1250 ISO (4 minutes and 5 minutes subs) through a WO zenithstar 80mm.

The sombrero is around 70 minutes at ISO 1600 (4 and 5 minute subs)

Darks for both but no flats. I think I can see now what the flat frames are suposed to take away, the lighter area in centre of the 65/66.

I think I have the tracking down a bit better now, I still need to work on focus (bartinof mask arrived today).

I have a question. So far, Ive only done up to a max of 5 minutes for subs. I understand the ISO thing but how far can I push it with a Canon 30d at F6.8? I was thinking of trying up to 10 minutes next time out. Any thoughts?

Cheers lads....

Criticism welcome (but be nice)

[graham.hobart (Graham stevens)]

First of all, cracking shots Starcrazzy. That is a reet good collection of galaxies.
For your question -I have pondered this recently and this is why it is foremost on my mind.
How long can you go with an unmodified DSLR?
Well for me with a 1000D I reckon anything under 10 minutes is ok as long as the ambient temperature is below 17'c or around that and dropping. I have severe sensor noise above that with long exposures and the darks have too.
You have a better camera than me (everybody has!) but I think unless you cooled your DSLR or allowed lots of time between lights, or shot in Antarctic conditions, you would be running into sensor noise and and hot pixels. The bane of DSLR's but they are cheaper so woo hoo !! and your pictures are very good anyway

[Starcrazzy]

Thanx heaps Graham. early days yet for me, but i think im getting hold of the basics.
I spose it can't hurt to experiment, push the sub times up until it gets ugly, then back it off a bit
Thanx again for the comments.