Help with first autoguide

[paul101]

Hi

im about to try my first go at auto guiding and have a few questions, hope you can help.

When setting up, using phd with laptop via st80 mounted on a 200mm PDS newt, and HEQ5 pro. do i set my scope up as usual, 3 star align etc. slew to my intended target, make sure its in the viewfinder. pick a guide star etc. then do i just plug in the auto guide cable into the mount guide port and off it goes. Do i have to select anything on the synscan handset? just not sure if it is as simple as that.

Thanks again for everyone's help

paul

[SteveP]

Paul

What you've described is the process for aligning your scope for GoTo purposes. When autoguiding, this is still required in that it helps to find targets that much easier. However in addition, you also need to 'polar align' your mount as well, ie align the mount so that it is parallel with the earth's polar axis. There are several ways to do this including manual drift alignment or software controlled using a CCD or webcam.

If you have a search on here, you'll find lots of advice on the different approaches for polar alignment. I'm not familiar with PHD so can't comment on whether it incorporates any polar alignment routines itself.

HTH

Steve

[paul101]

hi steve, thanks for the reply.

i can polar align my scope quite accurately, i have taken quite a few images using my SLR and have had good tracking with upto about 2min exposures. just want to try auto guiding to get longer exposures. just not sure on the procedures of setting it all up really.

just wasnt sure if i setup as normal then get guide star in PHD then just plug in the auto guiding lead into the port on my mount and off you go.

Hope it is that easy but im sure it wont be!

thanks

paul

[SteveP]

Hi Paul

I can't help you specifically with PHD but here's what I do using Maxim to both guide my mount and acquire the images

1. Link all the various bits together (mount, imaging camera, guide camera, focuser etc ) including having the guide camera connected to the mount's ST4 autoguiding port and the various connections made to the laptop

2 Polar align the mount. I use PemPro and try to get it to within 3-4 arcmins of the pole

3 Align the mount for accurate GoTo's - I happen to use Maxim's version of plate solving for this in conjunction with TheSky6 using the Sync command. Effectively it's a 3 star alignment but I tend to use 6-8 reference points

4 GoTo the object I intend to image

5 Start the autoguiding process within Maxim, ie find a guidestar, and then calibrate the mount. This important stage tells Maxim how to correct the mount as the signals from the guide camera are received. I expect there to be something very similar in PHD

6 Once the mount has been calibrated, start autoguiding on the guidestar and wait for it to stabilise

7 Start imaging

I suspect that one area you'll need to look at in particular are the detailed PHD settings, eg aggresiveness or whatever PHD might call it, which is how you fine tune the software to your particular set-up. There are some examples on SGL of what others have used successfully in PHD. You might want to have a look at them

I hope that this gives you some ideas about how I do it which you can read across to PHD

Steve

[Sparrow]

Hi Paul - I autoguide with PHD so I'll give you my procedure (BTW I actually pulse guide through the handset rather than direct to the ST4 port but that shouldn;t make any differenece to this procedure).

Get everything plugged in including the cable to the ST4 port.

Switch on and do your usual polar alignment and alignment routine with the scope.

Next, I usually use "precise goto" and use this opportunity whilst on a bright star do check my focussing.

SLew on to the target and do a few test subs to make sure I have the target centred in the FOV.

Now start PHD and start the camera to get an image on the PHD screen.

Select you star to guide on and start it off calibrating.

Once it's calibrated and guiding, you can start imaging - I usually let the guiding settle down for a minute or two before I start imaging.

One problem I have which may just be my set up is that after calibrating, the guide star is no longer in the original position. To solve this I use a small program that puts cross hairs on another star in the FOV and then calibrate - once calibrated, I stop it guiding, re-align the star in the cross hairs and start guiding again - this makes sure that my target to image is still centred.

Hope this helps

Regards

John

[paul101]

Thanks for all the tips, just need the clouds to [removed word] off now!!