December 2004 - Utah-Astronomy - mailman.xmission.com

Re: Fisheye lens
by Chuck Hards 09 Dec '04

09 Dec '04

When I was working in the lab I used one of the high-dollar lenses for the big Durst (this enlarger ran on rails on the floor, what a huge beast, took up to 11x14 negs) in a similar manner (also 4x5 format, which in retrospect was probably too large for the exposure times I used and the emulsions of the day), being an old copyscope builder myself. I was never satisfied, even though that lens was worth tens of thousands of dollars, none of them are designed for an infinity focus. But I too was awed by a piece of equipment that was worth more than I was at the time! You know, thinking about it, the only time I ever saw the Digistar in action was a demo done for the astro club about the time the original was installed. I haven't seen a real, scheduled star show since the late '70's I guess. Lotsa laser shows back then, though! Thanks everyone who had input on the fisheye lens topic. >Brent Watson wrote: > Chuck, > > I did shoot a couple of photos through the original > Digistar lens. It was a 43 mm f2.8 160 degree FOV > lens and covered a 5 inch circle. I put a 4X5 > adapter > on it and attached it to my Byers mount. I let it > go > unguided for about 30 minutes. I was using > Ektachrome > - probably ISO64(???) > > My recollection is that I didn't get much in the way > of stars. I could barely see the Andromeda Galaxy. > I > also did not see much trailing either. I didn't > look > for trailing due to atmospheric refraction, so I am > afraid your original question is unanswered here. > > It was fun to use a $25,000 (1980 dollars) large > format fisheye lens though. __________________________________ Do you Yahoo!? Yahoo! Mail - You care about security. So do we. http://promotions.yahoo.com/new_mail

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Ho Ho Ho
by Chuck Hards 09 Dec '04

09 Dec '04

I have a gently used, older pair of 7x50mm generic-brand binos that I would like to give to a deserving individual or family. Please email me OFF-LIST if you have a need or know someone who does. They will have to be picked-up, day and time TBD. Please, no otherwise well-off "bargain hunters", I want these to go to someone who deserves them. The first respondent who has a qualifying case gets them. Thanks, Merry Christmas! __________________________________ Do you Yahoo!? Meet the all-new My Yahoo! - Try it today! http://my.yahoo.com

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OT: JPL van crash
by Dale Hooper 08 Dec '04

08 Dec '04

I heard on the radio that there was a JPL van with ~10 people that fell about 200 feet this morning. According to my JPL contact - it was an employee vanpool vehicle that went off the Angeles Crest Highway on Mount Wilson. There are at least three fatalities. I'm not sure what project they were working on.

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And you thought your day was bad... (OT)
by Patrick Wiggins 07 Dec '04

07 Dec '04

Next time you're having trouble with some project, just think of this: http://www.trilobyte.net/paw/temp/BADDAY01.JPG http://www.trilobyte.net/paw/temp/BADDAY02.JPG http://www.trilobyte.net/paw/temp/BADDAY03.JPG :-) Patrick

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Fisheye lens
by Chuck Hards 07 Dec '04

07 Dec '04

Has anyone (Rob? Patrick?) tried tracking fairly long-exposures with a "fisheye" lens? I'm wondering if, guiding on a star near the center of the field, if the edge stars trail because of differential atmospheric refraction? A few years ago I acquired a nice fisheye lens with a FOV darned near 90 degrees, and would like to try it on the sky when the weather warms up. Any meaningful input based on experience is welcome. __________________________________ Do you Yahoo!? Yahoo! Mail - You care about security. So do we. http://promotions.yahoo.com/new_mail

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Re: Fisheye lens question
by Chuck Hards 07 Dec '04

07 Dec '04

Without waiting for the digest, it hit me on the way home tonight, and Debbie provided the clue when she sent me a frame she shot with a 50mm lens. (nice shot, BTW) The image scale is too small (with extremely short f.l. lenses) to even worry about differential refraction causing tracking errors on different parts of the frame. It shouldn't be a problem at all. Thanks Debbie! __________________________________ Do you Yahoo!? Yahoo! Mail - Find what you need with new enhanced search. http://info.mail.yahoo.com/mail_250

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Re: [Utah-astronomy] Fisheye lens
by Chuck Hards 07 Dec '04

07 Dec '04

Hi Debbie, thanks too for the off-list reply: I started shooting astro photos over 30 years ago, I am aware of all the caveats; airplanes, sky-fog, tracking limits, etc. My current set-up is homemade (actually a heavily modified commercial mount from the '70s), I do not use PEC, autoguiders or any digital aids, although I do have a couple of the old Astro-Physics autoguiders. They took all the fun out of it! :( I guide manually, strictly; I've become rather good at it and enjoy it (it's not hard, really. Really!). Go-to mounts and other commercial astro-hardware "for the masses" are not needed here. Old habits I guess. I just had a question about trailing near the edge of the field with a wide-angle lens due to differential atmospheric refraction. (much wider than a 50mm, I'm talking about something shorter than 17mm). You can get the zenith AND horizon in the same shot! What-if stuff. Rob, thanks for your off-list reply also, but the digest just came-through anyway. I use a pair of ancient Pentax K bodies, the fisheye lens in this case is the Russian Zenitar K2,8/16, got for pennies on the dollar on eBay a couple of years ago. Yes, I know it's "student" gear, but I am not going to replace it with high-dollar stuff because it works, works well, I'm used to it, it's paid-for, all my adapters fit it, and money for all-new equipment isn't likely unless it falls from the sky, so any suggestions would have to refrain from including new commercial hardware to be useful. Thanks again! > From: <astrodeb(a)charter.net> > To: Utah Astronomy > <utah-astronomy(a)mailman.xmission.com> > Date: Tue, 7 Dec 2004 12:00:30 -0700 > Subject: Re: [Utah-astronomy] Fisheye lens > > First of all, you would need a very dark sky to > avoid sky fog. My last batch of slides were limited > to 10 minutes because of the sky conditions. With my > two-star alignment with my polar scope, I could have > gone up to 30 minutes unguided with my 50mm lens if > the sky conditions would of allowed it. A fish-eye > lens would be even more forgiving as far as tracking > goes. > > Does your mount have PEC? The best mounts, provided > they are accurately polar-aligned and PEC trained, > can be left to track unattended and unguided for 30 > minutes or more. Of course, the longer exposure the > more there is a chance of getting airplane trails. > > My 2 cents, > > Debbie __________________________________ Do you Yahoo!? The all-new My Yahoo! - What will yours do? http://my.yahoo.com

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Re: [Utah-astronomy] Fisheye lens
by astrodeb＠charter.net 07 Dec '04

07 Dec '04

First of all, you would need a very dark sky to avoid sky fog. My last batch of slides were limited to 10 minutes because of the sky conditions. With my two-star alignment with my polar scope, I could have gone up to 30 minutes unguided with my 50mm lens if the sky conditions would of allowed it. A fish-eye lens would be even more forgiving as far as tracking goes. Does your mount have PEC? The best mounts, provided they are accurately polar-aligned and PEC trained, can be left to track unattended and unguided for 30 minutes or more. Of course, the longer exposure the more there is a chance of getting airplane trails. My 2 cents, Debbie > > From: Chuck Hards <chuckhards(a)yahoo.com> > Date: 2004/12/07 Tue AM 09:41:29 MST > To: Utah-Astro <utah-astronomy(a)mailman.xmission.com> > Subject: [Utah-astronomy] Fisheye lens > > Has anyone (Rob? Patrick?) tried tracking fairly > long-exposures with a "fisheye" lens? > I'm wondering if, guiding on a star near the center of > the field, if the edge stars trail because of > differential atmospheric refraction? > A few years ago I acquired a nice fisheye lens with a > FOV darned near 90 degrees, and would like to try it > on the sky when the weather warms up. Any meaningful > input based on experience is welcome. > > > > > __________________________________ > Do you Yahoo!? > Yahoo! Mail - You care about security. So do we. > http://promotions.yahoo.com/new_mail > > _______________________________________________ > Utah-Astronomy mailing list > Utah-Astronomy(a)mailman.xmission.com > http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy > Visit the Photo Gallery: http://www.utahastronomy.com >

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Jupiter Occultation Reappearance at 2:45 AM tonight.
by daniel turner 07 Dec '04

07 Dec '04

Jupiter Occultation Reappearance at 2:45 AM tonight. We won't see the disappearance but the reappearance will be visable if you can find a low eastern horizon. I'll make the trip up Emigration canyon to the Little Mountain parking lot but I plan to view through the windshield with binoculars........ with the engine running. Brrrrrr. DT __________________________________ Do you Yahoo!? The all-new My Yahoo! - What will yours do? http://my.yahoo.com

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Re: [Utah-astronomy] Re: Kodak E200 processing
by astrodeb＠charter.net 04 Dec '04

04 Dec '04

Thanks for clearing that up Patrick. I was totally confused when they said they couldn't do push processing back in October. I may send my next roll of film up to Salt Lake to Borge Anderson. We have friends who routinely go up there. I'm beginning to get the hang of tracked piggy-backed astrophotography. However, I'm going to get into digital astrophotography as soon as I get a telephoto Canon EOS lens. The digital camera is blind to the h-alpha wavelengths so I'm still going to take slides with either E200 film or Fuji Sensia 400 film. I can't afford to replace all my lenses yet with EOS "L" series lenses. Debbie > > From: Patrick Wiggins <paw(a)trilobyte.net> > Date: 2004/12/03 Fri PM 01:56:40 MST > To: Utah Astronomy <utah-astronomy(a)mailman.xmission.com> > Subject: [Utah-astronomy] Re: Kodak E200 processing > > Hi Deb, > > What you were saying just didn't make sense so I called Camera Country > and talked to their E-6 guy. Turns out, what you heard from their sales > person is what they tell folks taking "normal" pictures (I guess that > proves the rest of us are abnormal...). We are to the right of the Bell curve in intelligence. That is what I like to think about amateur astronomers. > > However, when I explained you were going to be taking pictures with > exposures lasting several minutes he said that changes everything and > that the setting on the camera in such cases makes no difference. > > So, what you need to do is take the film in and just ask them to push it > one stop (makes it ISO 400) or two stops (ISO 800). > > It was kind of interesting that when I started getting into how pushing > is accomplished (extending the development times) he didn't seem to know > about that stuff. So I get the impression they're not really a custom > photo lab, but rather there's probably some dial on the machine they use > that can be set to No Push, Push One Stop and Push Two Stops. :-) > > I hope this clears things up. > > Patrick > > p.s. Should you ever decide to try your hand at processing the film > yourself, just let me know and I'll get you started. It's really not > that hard and there's something to be said for showing a picture and > being able to say "I shot and processed that myself". > > astrodeb(a)charter.net wrote: > > > > Hi, > > > > I just called Camera Country and found out they do E6 and push processing. I just need to set the ASA film speed to 800 for "Push 2" or set the film speed to 400 for "Push 1". > > Last time I set the film speed to ASA 200 and that's why they couldn't push the film. This is the way I understand it. > > > > However, as Joe said a "Push 2" will make the film more grainer so I may just do a "Push 1" next time. According to the January 1999 Sky and Telescope issue, Ektachrome E200 pushed two stops in a good option for camera-on-tripod shots. > > > > Thanks guys for the tip on Borge Andersen. I'll keep that in mind. > > > > Debbiee > > _______________________________________________ > Utah-Astronomy mailing list > Utah-Astronomy(a)mailman.xmission.com > http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy > Visit the Photo Gallery: http://www.utahastronomy.com >

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