Hey, I'm pretty new in astrophotography and astronomy at all, few days ago I took 13 pictures of M13 in 30sec and stacked them with IRIS 5.5 Telescope I used http://telescope.bg/bg_celestron/img/c914sgtxltb.gif (ADVANCED C91/4-SGT (XLT) D235 F2350, f/10) and Canon 350D. So I wondered if these pictures are enough good for this technics or I can do pictures better, also after using software IRIS I did not use any other program to make photo better and even that it looks a little bit like I did it on photoshop. So please see and give your opinion http://photos-b.ak.fbcdn.net/hphotos-ak-snc1/hs194.snc1/6529_1033614257636_1743835481_58537_1896919_n.jpg thanx :)

You're using a Canon 350D you can use the EOS utility software to capture images. However, for programed exposure control you will be limited to 30 seconds. If you want you can purchase a DSUSB controller and cable from Shoestring astronomy, then download DSLR Shutter from Stark labs to take pre-programed sequences of exposures as long as you like.

Nevertheless, with that telescope 30 second exposure with the 350D of M13 is long enough, 13 exposures should be enough but more would be better. You will also want to shoot some dark frames and maybe even some flats. Different subject that can be covered in the image processing forum.

After alignment and stacking of your light frames(Subs) you will want to save the file to a 16 bit tif file then finish processing in Photoshop or similar image editing and processing software. There is where you will bring it all together for presentation.

here are a couple I took with a 350D

http://cs.astronomy.com/asycs/forums/p/39069/411621.aspx#411621

http://cs.astronomy.com/asycs/forums/p/35470/392222.aspx#392222

I could see your image, the link didn't work for me

Oh, sorry I correct my link. Yes I made one 30sec dark but no flat. I already have that cable http://4coolpics.com/forweb/Fig_3-4.jpg something like that, so I can make longer exposures but the problem is not there (actually I made 30sec because of the telescope). Thanks for the tips I didn't know these programs. But I don't understand what EOS utility software is for? And as I see your photographs there is a difference between...

Looks like you over stretched the histogram on both ends.

1 Dark frame is not enough, you need at least half as many darks as you have light frames, Preferably a 1:1 ratio.

For the Hurcules and many more globular clusters 30 second exposure is plenty. I typically shoot them with ISO 800 for 30 seconds.

You are using a Canon EOS Digital Rebel XT/350D correct? You should have received a CD with it that includes the EOS Utility programs, Digital Photo Professional, Zoom Browser and Canon photo-stitch. I recommend reading the tutorials and learning how to use them. They are relatively easy and simplify your image capture process.

Other reasons my images look different other than sky conditions is the software I use for image capture, stacking and processing. I've looked at Iris but don't use it. For image capture with my Canon DSLR I use the Canon EOS Utility software, For stacking depending on how many frames and what object it is and under what conditions when captured, I will use either Deep Sky Stacker(DSS) which is free, or Nebulosity which is more hands on and costs. For final processing I use Photoshop, but you can use Gimp or Pleiades PixInsight lE which are free and do a sufficient job.

Through the process of image capture to the end of post processing you should keep an eye on the histogram and be careful not to clip the dark points too much or the white points too. Space isn't black and the whites such as the core area of the globular shouldn't be blown out. You want to find the balance that is in there somewhere.

oh thanks for the tips :)