Hi guys,

Here is my first attempt at taking a photograph of a DSO through my 8" SCT. It took almost 2 hours to do the drift alignment. Can anyone explain why the stars are still not properly in focus? This was the best focus I could get.

Thank you.

Canon 300D at prime focus, 8" SCT FL 2048mm. 27 x 15 seconds at ISO 800. Processing and stacking in IRIS.

Good first attempt - hope some of our astrophotographers here can give you some advice on how to do even better next time.

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[quote=clop;833673]Hi guys,

Here is my first attempt at taking a photograph of a DSO through my 8" SCT. It took almost 2 hours to do the drift alignment. Can anyone explain why the stars are still not properly in focus? This was the best focus I could get.

[quote]

It could be the atmosphere wasn't very stable. In the time you took the shot, the stars could have been bouncing around causing the soft look to them. How high was the cluster? It it's low in the sky, it will quite often look like that also due to thick atmosphere you are shooting through. What software did you use to take the image?
Good start though!

Tom
Astro-shack observatory

[quote=tegwilym;833821][quote=clop;833673]Hi guys,

Here is my first attempt at taking a photograph of a DSO through my 8" SCT. It took almost 2 hours to do the drift alignment. Can anyone explain why the stars are still not properly in focus? This was the best focus I could get.

Thank you Tom. I think you might be right. The cluster was only 11 degrees above my horizon. The stars did seem to be bouncing around a lot, even during the drift alignment. I'll try something a bit higher in the sky next time. I was hoping to have a go at 47 Tucanae but it's too close to celestial south - my camera on the tele-extender doesn't fit between the telescope and the wedge. I don't think I used any software to take the image - I let the telescope mount do the tracking and took RAW images with the camera exposure time set on 15 seconds.

Thanks again.

You might try something almost straight up. That way you'll get pretty good focus and less atmosphere to bounce things around. Something kind of easy and somewhat bright. I took an image of M2 last night, and also looked at M5 with my camera. It only took about 15 seconds to see it, so if you took a bunch like that (maybe under 30 seconds) stack them, and you'll have a pretty good image. Drift alignment is a pain, but my scope is mounted on a 1/2 ton cement pier, so I'm ready to go in about 10 minutes!



Tom