Autoguiding equipement

[aGreyarea]

Hi all,

After seeing my best result at M42 fall short of what I would like and a full 2mins of the horsehead that might as well have been a dark(!), I've decided I need to at least try auto guiding. But I have a serious weight and budget limit!

I have an f/4 newt, an eq5 with the synscan upgrade (latest version), a laptop with only 3 usb's, a 50mm finder and an unmodded SPC900 with a 1.25" adapter.

Am I right in thinking that with shoestrings new USB2EQ5 cable and the 'Guide Camera Adapter for Finders' from Mod Astronomy, I'd have the equipement I need for basic autoguiding?

What concerns me most is focussing the guider as I have read about having to cut the tube length to achieve focus.

Many thanks

[angusb1]

Try metaguide, it may work well with your unmodded SPC900 and also doesn't need the guide star to be in focus to work.

[aGreyarea]

Great I'll give a go thanks!

[jgs001]

Some people have had success with an unmodded webcam and others (myself included) haven't. PHD has an option for using an unmodded webcam as a guide camera.

[dmahon]

I think you may find it difficult with an unmodified webcam AND a 50mm finderscope. If you could stretch to a better scope OR a better camera (including the home-brew LX modification of your current webcam), you will probably find things a lot easier.

[aGreyarea]

OK thanks, I'm not sure of the weight of the 8" and have seen conflicting advice about imaging weight limits for the eq5 so am reluctant to add a bigger guider. When you say better camera/lx mod do you mean I must be able to get 1sec(ish) exposures on the 50mm finder?

Also am I right about the USB2EQ5 being the only thing needed (software excepted) to control the mount from the laptop?

[bamus]

HI

I have managed to capture 7.5mag star with my finderscope and unmpded webcam. Have a look here:

http://stargazerslounge.com/imaging-discussion/125230-unmoded-webcam-guider.html

and to control mount with laptop you need USB to RS232 adapter. I have bought one on ebay for 2,5 pounds.

[aGreyarea]

Thats great Bamus, Thanks! Really useful thread. Have you already tried the cable or are you still waiting for something other than cloud!?

[angusb1]

One of the best things about metaguide is that it stacks in realtime so the need for long exposures is greatly reduced. Since Yoddha suggested it in bamus' original post I have a had a play around with it and found it greatly increased the effective sensitivity of my unmodded spc900.