Glen: Truth be told, I don't really have a clear understanding of all the mechanics you explain here (not really knowing anything about telescopes or guns), but the details don't matter: what's impressive is your inventiveness--good luck with whatever it is you're trying to build, but your point about the police seems to be a wise one--don't forget it!!! Cheers, Christine
----- Original Message ----- From: "D. Glenn Arthur Jr." <[EMAIL PROTECTED]> To: <[email protected]> Sent: Monday, July 21, 2008 1:30 PM Subject: Re: PESO: Hot Air > Rick Womer <[EMAIL PROTECTED]> asked: >> Neat! Where were you, and how far away was the chopper? > > Short answer: I was at home and the helicopter was a mile away. > > The chopper was over downtown Baltimore, MD, US, preparing to > land atop the University of Maryland Medical Center. I was > about a mile to the west of that (1.1 miles according to my > car's odometer; I haven't double-checked that with Google Maps > yet), using the telescope I borrowed from my brother (which > he describes as "a cheap, Wal-Mart scope" -- f=700mm, d=60mm, > poor correction (if any) for chromatic aberration and spherical > aberration (I got colour fringing when I tried to shoot Jupiter > and didn't have it centered), a similarly cheap "Barlow lens" > (2x teleconverter, more or less, as far as I can tell), and > using a cymbal stand with a boom instead of a tripod, because > the tripod that came with the scope doesn't work so well for > leaning out a window and looking sideways. > > Just to complete the picture of the kludginess involved: the > telescope/microscop->Kmount adaptor I'm using (given to me > by a bandmate a few years ago) is sized for a _real_ telescope > ... and this scope uses eyepieces that various amateur astronomy > websites describe as "occasionally found on cheaper, department > store telescopes", so instead of fitting into the receiver > tube it slides _over_ the tube and I'm holding it on with > gaffer's tape. (I'll eventually either get a cheap eyepiece > adaptor that'll fit the camera adaptor, or drill and tap holes > for set-screws in the camera adaptor.) > > So, near as I can figure, that was 1400mm and f/22, on a wobbly > support. > > > My brother also gave me the wooden stock from a busted rifle; > I'm going to try to turn it into a grip for the scope+camera > combination to make it a little easier to use handheld than it > currently is. I plan to put two shutter switches on it: one > roughly where the rifle's trigger had been, and one up under > the telescope, so I can use whichever hand isn't fussing with > the focus knob to trip the shutter. I'm hoping that having > a big, fat, white thing on top instead of a slender, dark rifle > barrel will keep the police from mistaking the rig for a weapon > once it's completed. > > In the meantime, I should get up on the roof at some point and > use the proper telescope tripod. But I haven't gotten around > to that yet. > > -- Glenn > > -- > PDML Pentax-Discuss Mail List > [email protected] > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and > follow the directions. > -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
