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olivemai
Joined: 25 Nov 2007
Posts: 10
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 Posted: Sun Jan 13, 2008 5:29 am Post subject: Star trail photography, request from a newbie? |
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| Some time this spring, I'd like to take some time to do some pictures, first of star trails - then of different night sky objects. From the results of the star trails, I can change the settings that I want for future shots of things like the ISS and Iridium satellites - something that I have wanted to do for a long time.My specific questions are basically regarding 'how to start'.I have 2 Olympus OM-1s and a variety of lenses. I suspect that I want to shoot with the wider lenses and go from there.What brand and speed of film should I start out with?Who should I have process the film?Aperture settings?Shutter speed settings?I have 1 tripod and a shutter release cable.I just don't want to take a pack of Walgreen's brand film and shoot crap shots if I have a starting place.Bonus.... Best suggestion will get to see my work when I accomplish it! |
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ohohohohoh
Joined: 24 Nov 2007
Posts: 10
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| Posted: Sun Jan 13, 2008 11:05 am Post subject: Star trail photography, request from a newbie? |
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| You can determine the aperture settings by looking at stellar brightness.http://en.wikipedia.org/wiki/Apparent_magnitudeKeep in mind that the sun is -26.5 mag. Stars you want to shoot are generally in the range of 0-5 mag or so. From the apparent magnitudes you can calculate the ratio of the sun's brightness to those of the stars you are interested in. Your exposures will take between ten minutes to probably six hours. I just made a few really nice shots with a digital camera. Exposure times were 20-30 seconds (I did NOT want star trails), I used a 50mm 1:1.4 lens and aperture settings of 11 and higher with an effective sensitivity of 400. This might or might not scale properly to film... I don't have experience with real film. But as you can see, you will likely have to use really high aperture settings because your exposure times will be very long. Use the lowest sensitivity film for best resolution and colors. As always, have it processed by a quality lab. And bring a sleeping bag and some hot chocolate. Good luck! |
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oldenoughtoknowbetter
Joined: 27 Dec 2007
Posts: 5
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| Posted: Sun Jan 13, 2008 4:41 pm Post subject: Star trail photography, request from a newbie? |
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| I'm not into astrophotography much myself, but my wife has made some star trail shots. I know that Ektachrome 200 is the preferred slide film, but I'm not sure what's the best negative film, since I only ever shoot slides. Well, to be honest, I haven't shot anything but digital since I got my first digital camera! Don't go for the fastest films, because they suffer badly from repricocity failure with long exposures: ISO 200 seems to work well.To get trails, you need to expose for at least half an hour. I'd recommend setting the aperture two or three stops below wide open to avid overexposure and the lack of sharpness most lenses show at full aperture. I was attempting to NOT get trails, so I used exposures around 10 to 15 seconds with an 85mm lens, aperture wide open.Try to find a custom lab to process the film. Tell them that they're astronomical pictures, and not to cut the film (since they won't be able to see the frame edges). I often include one non-astro shot at the beginning and end of the roll to serve as a reference. |
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