Dumbbell Nebula, M27

I'm starting to get to grips with setting up, aligning and focussing my 8" Edge HD telescope, so my unguided tracking is more accurate. On Friday night I had it set up so that 30-second exposures were mostly pin sharp. This is a stack of 14 such exposures, totalling 7 minutes on an unmodded 5D MkII at ISO 6400, using flats, darks, dark flats and bias frames. My limiting magnitude just about reaches 18.0, even though the night was not the clearest and the gibbous moon was up - I was just too impatient to get using the scope!

I'm especially impressed that Celestron's claim about pinpoint stars to the edges of a 35mm sensor frame is true!

Beautiful photo Mark.

It's good to see someone getting in there and shooting unguided, especially at that focal length. Well done. Stick at it.

Steve.

great shot!!
For the uninformed noob, is an 8" scope the equivalent to a 200mm lens, or does it not work like that?

Take the telescope aperture diameter, 200mm and multiply by the f-ratio, probably 10 for a SCT. This equals the focal length (2000mm in this example). For the apparent magnification divide that number (2000mm) by the diagonal of your sensor (about 50mm for full frame).

Yes, 2000mm focal length in this case. The 8" (200mm) describes the front aperture.

That's a good scope , and your doing a good job . Just keep on scoping and taking picts . Nice pict above , just needs more time like 5-10 mins per each picture then stack a bunch . More signal produces more data = better picters !

Thanks Celestron. I'm going to start doing longer stacks as I get more used to the scope. I'm just impatient to get started!