Re: [Utah-astronomy] Re: Autoguiders
Thanks Chuck, Patrick, and Rob. I have a couple of questions. 1. I found some slide film that I bought from Lumicon in '97. Will this film still work? It is Kodak P1600 film. 2. When you guys say a "long exposure", is this longer than 10 minutes? I doubt that I will be making exposures longer than 10 or 15 minutes. Debbie
Hi deb The 1600 ASA film is history and the quality is flat. Get new film, always use new fresh film and when storing film, keep it in the refrigerator even the freezer is moisture sealed well. Long exposure is anything longer than normal exposure. Anything that can't be done handheld is usually long exposure and for astrophotography the moon is a short exposure (100ASA F8 @ 1/500 to 1/125 sec.). Sky photos can be from a minute up to hours, depends on film and object, sky brightness and alignment. The longer the focal length means usually a slower optical system meaning a longer exposure for an average night sky object. Are we talking deep sky here or planetary/lunar?? Aloha,have fun Rob
Here's my take, Patrick and Rob may get slightly different mileage: --- UTAHDEB@aol.com wrote:
1. I found some slide film that I bought from Lumicon in '97. Will this film still work?
Personally I'd toss it and not take the risk with valuable observing time. At this point it's over 7 years old anyway.
It is Kodak P1600 film.
The grainiest color emulsion I have ever used. Didn't make for significantly shorter exposures when I tried it anyway.
2. When you guys say a "long exposure", is this longer than 10 minutes? I doubt that I will be making exposures longer than 10 or 15 minutes.
10 minutes would be very long for a comet shot, especially with such a relatively short focal length lens. I don't think I ever went over 5 minutes on Hale-Bopp. AS soon as I get access to a scanner I'll post some of those shots in the Gallery. Once you start doing astrophotography, suddenly you'll become acutely aware of the sheer number of aircraft in flight in the middle of the night. I don't think I've ever shot an entire roll without at least one aircraft trail on it! C. __________________________________ Do you Yahoo!? Win a $20,000 Career Makeover at Yahoo! HotJobs http://hotjobs.sweepstakes.yahoo.com/careermakeover
UTAHDEB@aol.com wrote:
Thanks Chuck, Patrick, and Rob. I have a couple of questions.
1. I found some slide film that I bought from Lumicon in '97. Will this film still work? It is Kodak P1600 film.
If it's been kept frozen you may be ok. At least that would be the case with regular film. I don't know about hypered film, though. If it's that old and has not been refrigerated the hypering is probably gone and the 1600 speed and image quality have probably been compromised.
2. When you guys say a "long exposure", is this longer than 10 minutes? I doubt that I will be making exposures longer than 10 or 15 minutes. "Long" is relative. But for piggyback photography 10 minutes seems to me to be a bit long.
Were it me, I'd probably shoot several series of 30 seconds, 1 minute, 2.5 minutes and 5 minutes exposures with the first series being shot wide open and each series after that closed 1 f/stop. Patrick
participants (4)
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Chuck Hards -
Patrick Wiggins -
Rob Ratkowski -
UTAHDEB@aol.com