Quote:
Originally Posted by Wavytone
Originally quarter plates, usually 103aO for which it was designed for. The snag is, even then we were stripping the emulsions off used plates and recoating them by hand in the darkroom. Not exactly sharp at the best of times and the 20" focal length was pathetic when you had a whopping 9" f/16 to use as a guidescope.
Someone added a cut-sheet film holder shortly before I left Canberra but I suspect you may have had issues with this if you weren't using filters and refocussing to suit as the focal length varied a bit with wavelength, the optics were really an aerial photography camera (as was the MOTS but I digress)
The worst part was that the increasing sky-glow in Canberra meant that the f/5 20" camera hit the sky limit pretty quickly. Even in the 1950's it had hit its limit. My 20cm f/7 Newtonian made a whole lot more sense - the slower focal ratio meant a far lower sky brightness, and the all-reflecting optics meant perfect achromatism (so no filters) and it was razor sharp. Took some awesome shots of clusters and comets on fine grain film.
Re the dicky drive... it was superb when I used it but as I recall, a few years later one of the Stromlo staff (he should remain anonymous) had a bit of an incident one night and the drive was never the same afterwards, I think the worm shaft was bent. There was some talk about an electric drive but nothing happened... Not that the university really cared about fixing it, as the Oddie was only for high school kids and basic teaching anyway.
The other thing was that other groups used it on other nights so the drive was invariably out of calibration when I used it; so you really had to know how to set the governor accurately.
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Yes I seem to remember a filter was necessary on the Zeiss to get sharp-ish images?
I also remember that story of the accident that stuffed the drive, huh, memories...yes, the drive was fine except for the jump.
The Newt sounds like it was pretty good...ahh the
good'ol 8" F7 huh?...ah memories
Here's a closeup of the Zeiss (showing the big plate holder) and our Celestron5 and home made cold camera mounted on it
Mike