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moon1.txt
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1993-10-09
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From: pmartz@dsd.es.com (Paul Martz)
Newsgroups: alt.binaries.pictures.misc
Subject: moon1.gif
Date: 9 Oct 1993 20:56:04 GMT
Organization: Evans & Sutherland Computer Corp., Salt Lake City, UT
Subject: The Moon on 9/22/93, during the Autumnal equinox
Format: GIF
Size: 660x486
This photograph of the moon was taken by me from my backyard in Salt
Lake City, Utah, USA. I used a Celestron Ultima 8 PEC telecope and a
Pentax K1000 camera. The shot was taken at the prime focus of the
telescope, with a 2X teleconverter in place. With the teleconverter,
the effective focal length of the system is 4000mm, and the effective
f-ratio is f/20. The expousre time is 1/250th of a second on TMAX 3200
film.
By "prime focus" above, I mean that the telescope was effectively used
as the lens for the camera. The eyepiece was removed from the scope,
the camera's normal lens was removed from the body, and with a
telescope/camera T-adapter I hooked the camera body up to the
telescope. The telescope has a 2000mm focal length at f/10, but with
the 2X teleconverter these numbers are doubled.
Adobe Photoshop was used to scan in the image from a Howtek scanner.
The only processing I did with Photoshop was to increase the contrast
a little. The image was saved to raw format and converted to gif with
the ppm tools.
In the original print, the thick grain of the fast (ASA 3200) film is
visible in some of the dark maria areas, but this did not scan in at
150 pixels per inch and is not visible.
This image is of the southern hemisphere of the moon. So if you get the image
and view it and it looks like the top half of the moon is missing, this is
normal. With a 4000mm lens it is impossible for me to get the entire moon
into the camera frame. If you are a stickler on these kinds of things, I do
have another photo of the moon taken without the 2X teleconverter at 2000mm,
and this shows the whole moon. I may have time to scan it in next weekend if
there is interest. It doesn't show anywhere near as much detail as this image
does, though.