guider scope question

[bri]

Hi folks

I'm thinking of buying a skywatcher ST120 600mm f:5 on an eq3-2 as a starter kit that can be taken out for a quick bit of general observing and some simple imaging with a dslr to start me off. Then eventually, when I've got the funds and some more knowledge, buy a 200/250 pds + neq6 pro for the more intensive imaging side of things.

My question is would the st120 be suitable as the guider once piggybacked to the PDS or is there something I'm not taking into account?

The reason I'm asking is:

I would have a grab and go scope with a dual purpose to keep the costs down.

Also while I'm on the subject, What would be the minimum quality guide cam that I could use to compliment the kit that I'm looking at getting? It will be primarily for dso's.

Thanks

[Merlin66]

The ST 120 would be overkill as a guider on the 250 newt!

I'm assuming you'll use something like a DSLR for imaging?

Then a "finder guider" or a ST80 would be a good compromise.

Re guide camera - the favourite seems to be the QHY5 used with PHD

HTH

[bri]

Thanks for the heads up.

As you have probably guessed, I'm not familiar with how this guiding works so I need to get my head around a few things.

I take it that the QHY5 is the cam that picks up the target and PHD is the software that "talks" to the mount?

As for the 120, could you explain to me why it would be overkill and why would the 80 be more suitable? I don't get it!

And yes I will be imaging with a Canon 40D as I started out in photography.

[Merlin66]

The 120 is relatively a big bulky, heavy scope...it will require very robust connections and supports to prevent flexing.... the ST80 is much lighter and easier to mount - it will probably still allow you to find a suitable guide star for a camera like the QHY5.

All in all any easier, safer solution.

Just my 0.02 euro.

- you're correct about the function of the guider....

[bri]

Thanks Merlin thats cleared that up nicely.

Baby steps....