Looking into guiding...

[ryandsimmons]

My current budget (£0) really means I have no money to spend on guiding at the moment, however while researching guiding I see that it may not be as bad as I was first fearing.  I was just wondering if the kind chaps here could tell me if I am on the right track with my half formed plan.  I am trying to research this but as usual everything is arcane and I just can't grasp some of the concepts.  I am happy with my 30 second subs, but would like to try some longer.

Basic equipment to work with:

C8 (f10)

CG5 GOTO mount

Canon EOS 1000d camera (unmodded)

The old Celestron Neximage webcam.

I also have lying around a Celestron 70eq and Celestron 130EQ.

I was thinking about trying the Neximage as a guider.  From what I gather I need to piggyback a small scope on the back or my C8 and connect it all up.

First question: Is it possible to whack the Astromaster 70 on to the C8 and use that with the Neximage as a guide scope?  Or would that just throw too much weight onto the mount? 

2) Assuming I can, is it just a case of whacking the Neximage into the Astromaster 70 and outputting signal to a laptop?

3) If that is fine, what software would I need on the laptop.

4) What cable would I need to connect the laptop to the mount?

5) Am I even in the right ballpark here?  From what I can glean the webcam is not great, and would only guide on bright stars which would limit my targets, but given I am a year away from actually spending money on guiding this would be better than nothing.

[DaveS]

I'm sure that some with more experience than me will come in on this, but I would think with an 8" SCT an off-axis-guider will be the way to go, together with a 0.63x focal reducer / flattener.

[Vega]

One excellent solution is a double finderscope bracket (like in a Y shape). You can the get one of those Orion guiders that fits in a finderscope bracket while still being able to use your finderscope as well.

[JRWASTRO]

I understand that your CG5 mount has an ST4 guide port. It is via this ST4 port that the mount motion will be corrected via the guiding signals.

You can use the NexImage  and Astromaster 70 as a guide scope combination. That is how I started. You will need to get a "ShoeString Astronomy" cable to interface the mount ST4 connection to the lap-top ( USB connecdtor). I used Guidemaster as the auto-guider program. I found the my Neximage not to be the best camera as a guider and there are not many camera control programs for the Neximage that allow for longish exposures.

A much better alternative :

A very easy setup for auto-guiding is the  " Orion StarShoot " autoguider. This unit is powered from the USB port via a cable to the lap-top machine  and uses PHD guiding (supplied) to control the in-built camera (far superior to the NexImage). This unit carries the camera  and the interfaces directly to the mount via the ST4 compatible connections.

FYI: This is an Aussie supplier but I am sure you can get this product in the UK :

 http://www.bintel.com.au/Astrophotography/Autoguiders/Orion-StarShoot-Autoguider/24/productview.aspx

This is the one I like. But like you I cannot spend this sought of cash when I have a working system already:

http://www.bintel.com.au/Astrophotography/Autoguiders/Orion-StarShoot-AutoGuider-Pro/1869/productview.aspx

Your main issues will be in the mechanical mounting ... but that is another issue.

Jeremy

[JRWASTRO]

I seem to have duplicated the links above. the first one should be :

http://www.bintel.com.au/Astrophotography/Autoguiders/Orion-StarShoot-Autoguider/24/productview.aspx

This is the unit that I use.

JRW.

[lensman57]

My current budget (£0) really means I have no money to spend on guiding at the moment, however while researching guiding I see that it may not be as bad as I was first fearing.  I was just wondering if the kind chaps here could tell me if I am on the right track with my half formed plan.  I am trying to research this but as usual everything is arcane and I just can't grasp some of the concepts.  I am happy with my 30 second subs, but would like to try some longer.

Basic equipment to work with:

C8 (f10)

CG5 GOTO mount

Canon EOS 1000d camera (unmodded)

The old Celestron Neximage webcam.

I also have lying around a Celestron 70eq and Celestron 130EQ.

I was thinking about trying the Neximage as a guider.  From what I gather I need to piggyback a small scope on the back or my C8 and connect it all up.

First question: Is it possible to whack the Astromaster 70 on to the C8 and use that with the Neximage as a guide scope?  Or would that just throw too much weight onto the mount? 

2) Assuming I can, is it just a case of whacking the Neximage into the Astromaster 70 and outputting signal to a laptop?

3) If that is fine, what software would I need on the laptop.

4) What cable would I need to connect the laptop to the mount?

5) Am I even in the right ballpark here?  From what I can glean the webcam is not great, and would only guide on bright stars which would limit my targets, but given I am a year away from actually spending money on guiding this would be better than nothing.

Your biggest obstacle to a succesful guiding is not the webcam but the scope. The scope has a FL of over 2000mm and this is difficult to guide to say the least. A 60 or 80mm fast guidescope is a possibilty but difficult to balance and the more practical option is an OAG but for this to work you'd need a pretty senstive guide camera. Not impossible but not easy either.

A.G

[ryandsimmons]

Cheers chaps.  I will check the off axis guiding.  That does seem pricey though.

I just saw this: http://www.ebay.co.uk/itm/Orion-StarShoot-AutoGuider-and-Orion-Mini-50mm-Guide-Scope-Excellent-Condition-/281476778007?pt=LH_DefaultDomain_3&hash=item418952c817

Although it says it is only good up to 1500mm and the C8 is 2032.  Would it really make much difgference?