Saturday, April 15, 2017

Temporary Neighbors

Shot with my Pentax K10D and a 500mm lens that cost me $50 on Craig's List.
 1/90th of a second, ISO 200.

1/90th second, ISO 100.

6 comments:

augustrrr said...

Are you too busy to use your telescope?

John Cunningham said...

Great shots, Clayton!! you guys will have to retuen to Alaska in the summer.

Clayton Cramer said...

Dor photographing birds?

w said...

I take it this $50 lens is not an ED one as there is a lot of purple fringing one would not see on a quality glass telephoto, but then an ED one at that focal length could easily cost $5000 for a Canon/Nikon/Pentax lens (maybe half or so for a Tamron/Sigma ED one).

Curious to know what f-stop/aperture you used and if it was the max for the lens. What brand/model lens is it? Lenses and especially non-ED ones usually have the lowest quality wide open.

But for $50 not bad... ;-)

I too am curious about the telescope question for taking pictures of terrestrial objects. Most celestial scopes stink for such a task. I have a mid 1980's Canon FD 800mm F5.6L lens (for 1970's and 1980's Canon SLR 35mm cameras)--a giant white telephoto lens (something like 12-16lb--forget the exact weight) and the kind seen at superbowls and world series games. I bought it in 1999 for $3,000 (new in '85 those were like $6K I think). It's ideal for terrestrial of course, but for celestial is it marginal except for Lunar where it is so/so. But then 800mm is only like 16x anyways. Another thing is terrestrial generally doesn't require lots of light gathering unlike a celestial scope.

I need to get an FD to EOS adaptor and look into possibly have a conversion done to use a universal mount for digital, but I still have a case full of slide film in my fridge for years (sealed of course) I need to use up first.... I really want the current EOS IS 800mm Canon lens, but at $8,000-$10,000 for that beast unless I win the lottery (I never buy tickets though...odds stink)...

w said...

Also, aren't all your telescopes reflecting rather than refractor? Now refractors can be used like a telephoto lens, but they leave a lot to be desired compared to a real telephoto lens which is why one never sees serious amateur or pro photogs using a scope (besides issues like lack of autofocus, etc) for terrestrial imaging.

Clayton Cramer said...

w: f/8, minimum. I will use higher f-stop in future. Don't remember brand and it isn't on it.

I have used the 17.5" reflector experimentally for terrestrial photography. Like many short focus reflectors there is a bit of fogging from light sneaking in around the aperture. I have a 5" refractor which I have never used for terrestrial photography, because I put an optical corrector on it that turned an achromat with some color fringing into somewhat close to an apochromat, but it changes the focal point so much I can't get it in the camera body through the diagonal that has the threads for the corrector. I need to build something that holds the corrector in and one that isn't a diagonal.