Having been able to obtain a tracking mount (a modified Meade telescope mount), I was able to jump straight beyond a barndoor tracker to something motorised. I built a support for the mount which would hopefully point the mount accurately enough at the south celestial pole. See some attached photos. The first show the wooden mount, levelled and aligned to the south pole. I built it with a 38 deg incline (my home latitude), and ensured all screws near the front were brass to avoid deflection of the compass. The rear legs are adjustable (old washing machine feet I think) to set an accurate level. The bullseye spirit level is very useful.
The old telescope mount is then put in place. Because the original on/off switch is then covered, I added a new toggle switch and a LED connected to a very low internal voltage so it just glowed (but easy to see in the dark) and didn't drain the three AA batteries.
The camera is mounted on a ball mount, a remote shutter release is added. Only one more item is needed - a right angle viewer - and I have one on its way. I'm actually taking the photo with my Pentax KX SLR 35mm film camera which I used for the astrophotography (my MESuper is on the mount as a prop). I have used a 28mm, a 55mm and a 135mm lens.
I'll post the first results in the astrophotography deep sky forum. I'm very pleased - the tracking was better than I had dared to hope for up to 10 min exposure.
I'm looking forward to a few more evening sessions shooting film.
Maybe one day I can own a digital SLR - that will make life much easier.
Thanks for reading
Eric
