[taxman (Matt)]

I am looking to put together a widefield setup for airline travel and those nights where I only have a hour or so for imaging. Basically, I want something fairly simple and self contained so I don't spend a long time setting up, checking power, drift aligning etc.

To that end, I have a Manfrotto 190XDB tripod, a Manfrotto 410 geared head (here in about a week) and my trusty unmodded 1000D along with a Williams optics RDF modified to fit into the hotshoe. When my tax return comes in, I will also be ordering a Skypatrol III.

Where I would like opinions is on the lens. I was tossing up between the 200mm f2.8 or the 135mm f2.0 and I was hoping there might be a few users who have had experience with either.

At the moment I am veering towards the 135 as the shorter f-stop means I can probably get away with 15-20 sec sub-exposures, reducing the setup time but the field is much wider than the 200mm f2.8, so I am concerned the image scale of anything interesting in the shot might be a bit small.

This will be my first camera lens >$1000 and I'd like to avoid my usual MO of getting something wildly unsuitable for the first few times so any thoughts or experiences would be appreciated.