I did some widefield photography at SPSP, with just the camera on top of the EQ6. Unfortunately a lot of them didn't turn out very good because of:
a) drifting in RA (no guiding)
b) battery on the mount was going flat so was getting more star trails than usual
I borrowed h0ughy's battery on the 2nd night so had less star trails, but just focused on some wider field milkyway shots with the Sigma 17-70.
Here's 2 of the shots that did come out.
1) Milkyway (single shot) about 4 minutes exposure. ISO800, 17mm.
2) Composite shot of tracked on milkyway and tracking off (foreground) both single shots about 3-4 minutes each.
Only processing was levels adjustment in photoshop. Transparency was generally terrible on both nights.
I wasn't there. My wife was having a baby that week so there was no way I was going to get a leave pass. Anyway that image makes me feel like I was there. I will ask Lachlan if he can get a larger copy of it from you. With your permission I think it would make a wonderful shot to use in the future with respect to the SPSP.
Great shots, Mike. Were these done with the lens wide open at 17mm? I'm quite interested in this lens. Does it have any tendency to change focus when pointing up?