Autoguiding with 135mm/200mm lens?

[Beardy Bob]

Hey guys,

Up until now I've been doing deep sky with autoguiding with a 600mm 'scope, but I have just picked up a couple of cheap lenses and was going to shoot some wider field stuff with the camera piggybacked on the mount.

My question is, would I still need to go to the effort of setting up the autoguiding system to do this? I'm going to be using a DSLR with a 135mm or 200mm lens on a HEQ5, with exposure times around 10-20min. I'm thinking that the answer is almost certainly 'yes' with these exposure times, but if anyone knows either way for certain from experience it would be handy to know.

[Gina]

Yes you need guiding for 20m exposures and 200mm lens on a DSLR. You can get away with 2m but not 20m, I've found.

[Toxic Coolaid]

Orion makes a nice kit that uses a finder scope for the camera to look through. It has a wide FOV and has worked very well for me imaging with a 800mm Newt. It would be much easier to get good guide star.

with SSAG camera

http://www.telescope.com/Astrophotography/Autoguiding-Solutions/Orion-Magnificent-Mini-Deluxe-AutoGuider-Package/pc/-1/c/4/sc/60/p/102418.uts

without camera

http://www.telescope.com/Astrophotography/Autoguiding-Solutions/Orion-Deluxe-Mini-50mm-Guide-Scope-with-Helical-Focuser/pc/-1/c/4/sc/60/p/102417.uts

[davew]

From experience ? Yes, you'll need to auto guide up to 20 minutes. ( With your lenses )

But..... try it first. I've found 5 minutes is fine. 10 minutes is ok but 20 is right out of it and that's with an expensive mount !

In my defence I do set up every night I'm out . I don't use a scope to autoguide but a small 100mm f2.8 camera lens. Works every time.

Dave.

[laser_jock99]

Unless your mount is really good you'll probably need to autoguide beyond 5mins with your 200mm lens. Small amounts of trailling will show up when viewing on your PC screen.

I use a cheap second hand refractor for the guide scope which now has my best lens permanently bolted to the top bar to give pinpoint stars.

Mad 6" guide scope with camera on top!

Picture of IC1396 with the above rig.

[Coco]

Of course you can, I use a 135mm f/3.5 Takunar M42 screw lens with my QHY5.

Here are my PHD settings, I get a flat ---- guide line apart from very low south where it has a small undulations ..

[Beardy Bob]

Yeah, I thought as much. It looks like I'll have to go through the rigmarole of setting up my auto guiding each time then!

[Beardy Bob]

Thanks for the responses.

[Coco]

Yeah, I thought as much. It looks like I'll have to go through the rigmarole of setting up my auto guiding each time then!

Why?