Jas, that's what the telescope is for.

The "zoom" level being dependent on the magnification level of your chosen eyepieces.
I don't see it as being of use on the finder.
I have both a red dot finder (RDF) and a right angle finder on my 10" dob.
I cannot get by without the two working together. The RDF, because of its zero magnification makes it very easy to plonk the scope straight on the star you see with your naked eye. Then the finder does the rest for star hopping.
Adrian, I had a right angle Telrad too. I had so much trouble trying to set that mirror up to get it to show stuff

. I thought it was just me.
And heaven forbid if you don't cover it back up (with it's dew shield, extra $) quick smart, because that thing got dewed up and rendered useless in no time flat.
I don't know why... but my RDF- the type with the square glass window (not the the long tunnel shape one) doesn't get affected by dew. Only once in the 4 years I've had it and that was at the end of a very long session on a particularly dewy night when everything was soaked that bad I shouldn't have been still out there anyway.