i've been looking into barn door mounts, i'm going to give the double arm type 4 mount a go, supposedly you should be able to do hour long exposures with extremely little to no star trails.
I made one once. It worked fine, but the moment I got a driven equatorial I abandoned it in favor of piggyback imaging. Somehow, I always think of barndoors as a stop on the road, but not the destination.
Geoff
my other way to get around using a barndoor mount is to take a bunch of short exposures and stack them, i took a few widefield exposures over the weekend, while i had teh pleasure of extremely dark sky out west, but now i'm wishing i'd taken a heap more photos, at a shorter exposure time. i only took 3 photos at ISO800 at 25s, i'm thinking that maybe 20 or so photos at 10 seconds, might have given me better results.
oh well, i'll let oyu know how the stacking goes any way
EDIT: attached my first stack, pretty primitive. composed of 3 photos, @ 25s @ ISO800 using DeepSkyStacker. i do believe my focus is out too.
