Exposing For Stars
Published : 15th February 2005
I am shooting a project on 35mm with a few POVS of the night sky filled with stars. I expect these shots will eventually be done digitally or by buying stock footage, however, it has got me wondering how to meter the stars and what stock and exposure times are required.
Does anyone have any experience with this? We will be somewhere very remote and I expect the stars to be fantastic, so I'd like to give it a try if it's a possibility.
I guy I went to college with years and years ago won a student Academy Award for his short film, called "Zebu," that was entirely shot at night using very long exposures. From what I remember he was shooting on 5294 with 30 second exposures. I don't know what his stop was.
It was very cool stuff. It would probably look incredibly better on 5218.
Art Adams, DP [film|hdtv|sdtv]
San Francisco Bay Area - "Silicon Valley"
30 seconds at f/2 with 5279 or 5218 does the trick.
You can get away with 20 second exposures, but I wouldn't recommend it. Depends on the telecine, stock, what the final outcome is.
Being in a remote locations helps, which is good. You also have to watch out for natural environmental conditions (haze, cloud), light pollution (even from a highway, not too distant town) and your sanity.
Get hot pads and find a way to stick 'em to the lens to prevent condensation. This can very easily and often happen over prolonged times. There's also a dew catcher device that you can get from astronomy stores.
I don't recommend shooting with Fuji. I once shot all night with Fuji-500 and came back with ... Black. Oh, until the sun came up.
Of course the stars will move at 30 second exposures, with only the slightest hint of trailing, so I don't know if that's what you want. If you want still stars, you have to get that mount (name escapes me at the moment) that astronomers use.
I notice you're in Toronto. Call me if you'd like, I can show you some footage shot years ago.
The Kodak website has information:
Astrophotography Kodak Publication P-150
Eastman Kodak Company
The exposure for stars on 500 iso stock is 20 -30 secs at T1.4. This gives stars that look like points of light and not streaks and a good black.
If your lens is slower I'd recommend pushing the film (especially 7218/5218) and keeping your exposures shorter than 45 secs.
On a Norris or similar system (or on a Bolex for that matter) you can expose for ,say, 30 secs and then advance quickly to the next frame so as to keep the actual shooting time short for the amount of final footage.
The best view is towards the celestial pole as the stars rotate around that point.
What really looks great is if the camera moves during the exposure with a bit of foreground in frame to give a 3 dimensional feel. You don't need a full motion control rig. It's relatively easy to get a battery powered, highly geared motor and rig either a belt or screw drive. You can use a variety of dolly’s and rails. My portable one ( you can carry it into hard to get at places) consists of linear bearings on twin 3.5 ft rails mounted on extruded aluminium rectangle section tube.
The camera need only move a few feet to get the effect. I've moved the camera as little as 3 feet over 6 hours