[Robert Shlaer]

Dear Demented Daguerreian Lunatics,

I have just had this forum brought to my attention, and would be glad to have my article on Lunar Daguerreotypy (rhymes with lobotomy) reprinted here.

I am done with the Lunar phase of my life, but if anybody would like to continue to pursue it, I have for sale the complete rig, telescope, guide scope, drive corrector, 4×5 custom astro camera, shutter timer, and everything else needed. Bulky and heavy, so you wold need to pick it up, at which time I can show you how to use it. Anybody who is interested should contact me at:

easterlyviews@earthlink.net

To answer some questions: the moon is an object in bright sunlight, although its luminance varies with phase. My telescope with barlow lens was about f:64, and a full moon exposure was around 2 minutes, 4 minutes for first or third quarter. In trying to get crescent moon images, the exposure was as long as 15 min using hypersensitized plates, which is about my limit of endurance using a guide scope and manual drive corrector. The moon’s apparent motion is very irregular. The automatic drive correctors with which I am familiar need a tiny object to use as the guide reference, so I do not believe they can work with the moon. Even though there are small bright details such as illuminated mountain tops near the terminator, they change continuously during an exposure as the illumination angle changes. It is hard enough to deal with one of them visually, trying to decide where the alignment point should be as the appearance changes.

Exposure times over 15 minutes are in my experience negated by reciprocity failure, at least with Hg developed plates. Get around many of the problems by making small images, say about 1″ diameter, instead of the approximately 3″ I was doing.

Planets are a loosing proposition unless you want a very small image, which will probably be indistinguishable from minor plate flaws. Not much point in that. You could do better with the point of a pin.

Good luck, anybody,

Bob Shlaer

[Author]

Posts