Help with astrophotography!

[Vagif]

I got a celestron 130 slt, and i want to buy canon 1000D to do some astrophoto. But with the mount i have (alt az) i think i can only do 30 sec exposure. Is there ANY fix to this? I wanna do like more than 5 min or so. 

Thanks in advance

Vagif

[tingting44]

not a chance for 5 min subs on an alt AZ mount mate, your best bet for longer exposure on your mount is to lose the scope completely and stick a dslr on the mount to reduce the focal length so star trailing wont be as noticeable.... i got the same mount as you and im hoping with an 18mm focal length i  can get somewhere around 60-90 second subs with out star trailing showing too much, maybe a wedge but ive had no use in them, if you want 5 min+ subs you WILL need an EQ mount + GUIDING

[ronin]

To get 5 minute exposures you will need a good equitorial mount with goto and a guide scope and guide camera.

You cannot really do long exposure AP on an Alt/Az the object being imaged will rotate making stacking difficult.

[Vagif]

But can i do like 100   30 secs exposures? So i like stop the exposure and start it again 100 times

[swag72]

But can i do like 100   30 secs exposures? So i like stop the exposure and start it again 100 times

Yes you can, but you will never get the same amount of detail as you'll get with longer exposures.

[ollypenrice]

You could put the mount on a wedge to tip it to the angle of your latitude, so making it an equatoprial. That's the theory. I wouldn't do that, it rarely works out well and is often a waste of time and cash. For AP you need an equatorial mount and that really is about the size of it. It's the same with all sorts of things; if you want to go cycle racing you need a bicycle. No way round it. A unicycle won't do!

Olly

[Vagif]

But how does this guy do over 30 minutes of exposure with the same scope and same camera that i have? I think he is doing like i told, 100 30 secs exposures. He is getting amazing photos!

[ollypenrice]

I don't know. The amount of field rotation does vary with where in the sky you are trying to image. You can try the multiple short subs approach but it simple doesn't compete with long exposures.

Olly

[Stargazer33]

Do you have a link to the photos that you mentioned in your earlier post?

[Alien 13]

But how does this guy do over 30 minutes of exposure with the same scope and same camera that i have? I think he is doing like i told, 100 30 secs exposures. He is getting amazing photos!

Hi, nothing is impossible but as already stated the alt az mount is not realy suitable for long exposures and not just because of the field rotation issues but if you already own one and have a camera then its allways worth having a go.

Shorter focal length camera lenses will maybe get you to a min or two exposures especially if you crop the edges most affected by field rotation but dont expect the stars to be pinpoints of light away from the center.The position of the object in the sky will have a bearing on the maximum exposure too.

Photographing the moon and planets with a webcam is possibly the best way to use your scope if you do want to dabble in astrophotography but i would advise you not to spend lots unless you want a DSLR for normal photography anyway.

Alan

[Vagif]

http://www.flickr.com/photos/66068077@N06/8412152208/in/photostream/

[Vagif]

So is it worth buying t-ring, t-adapter and dslr canon 1000 D?

[Uranium235]

You also need to hook it up to USB and use EOS utils (it comes on the disc with the camera), that will allow you to determine an exposure length of your choice (ie: 10x600, with a 30s gap between each exposure).

But, youre on an ALT/AZ mount with no guiding - so until you sort that out, 30s is as much as you can hope for anyway. You can get a de-rotator for AZ mounts, but if youre really going to take it seriously then you need a EQ mount instead.

[wxsatuser]

I would forget it as that chap with the 130 SLT cut 46mm off the tube and repositioned the primary for enough back focus.

[brantuk]

You seem dead set on astro photography with your new scope so (against my intuitions) I'm not going to try and dissuade you. What I will suggest however is that you postpone your decision until you learn everything you can about your scope and mount - and then decide what to do about imaging with it.

Here's a very useful review of your equipment which I've read through and tells you what you need to know:

http://www.jb.man.ac.uk/public/im/cel130SLT.html

Also I suggest you get the book "Making Every Photon Count" which will answer any further questions more fully than perhaps can be offered on a forum.  Good luck and I hope you choose well for yourself.