Need help in Astro-photogrpahy with Skywatcher Startravel - 80

[Annamalai]

I have recently bought a Skywatcher Startravel - 80 scope and I'm planning to do some astrophotography with it.Before this one i had 3 inch reflector and i have also done some astro-photography with Microsoft lifecam HD-3000 webcam without any problems. For the first time i attached the webcam to the 45 degree diagonal of my scope and i used sharpcam software to take snaps of moon.Sadly,the pictures i got with that scope was not so good.It was in focus but the image was blured with some details on moon.I think the problem is with my 45 degree diagonal.

I want some good images,Please help me!..............

[haitch]

Try without the diagonal. If you can't reach focus you might need an extension tube but there is no reason to use a diagonal for photography - it is just an extra optical element in the way.

You will also encounter chromatic aberration (CA) with an achromatic refractor like that which could also be part of your problem. You might want to try RGB imagin so you only have to focus one colour at a time.

HTH

[JamesF]

I wouldn't use a diagonal for imaging at all. If you can't achieve focus without one, use a straight extension. You may find that you can't avoid some colour aberration with the ST80 on a target as bright as the Moon and that may contribute to some of the blurring. An IR filter might help, or (I have no idea if this would work with the ST80 though I know people use the technique elsewhere) you could try imaging the Moon with an IR pass filter.

James

[Annamalai]

Thanks for the help i will try to image without the diagonal.

[LukeSkywatcher]

I agree. Leave the diagonal out.

[haitch]

Yep. As James says - filters, so you only have a limited range of the spectrum to keep in focus, is the way to go with an "achro" (forgot you might not be using an IR already having a reflector before).