How do you photograph (or video) shooting stars? I tried doing this once during a meteor shower and pretty much failed no matter what combination of ISO and exposure settings I played around with.
It must be possible, since there are photos out there. Nice looking photos. Before the days of Photoshop.
I can see night sky pictures being helped by longer exposure times (up to a point since after a while the Earth revolving turns star points into arcs). But shooting stars zip by so fast. You can increase the sensitivity, but then you get a lot of noise.
That was my suggestion, set the exposure to as long as you can to the point where the earth’s movement won’t interfere. I haven’t tried doing it in probably 20 years, but I think you can push a minute or so before you start having problems with all the stars starting to arc.*
But 30 seconds is fine.
Set it for 30 seconds and as soon as the shutter closes, hit it again…and again…and again…again. It’s boring and tedious, but that’s how you get it. It’s the same way you get amazing shots of lightning during electrical storms. You might take 100+ shots to get 1 or 2, but that’s just how it works with photography. At least with digital it’s essentially free.
*This is totally based on some sort of astronomy merit badge from Boy Scouts. I remember the person showing us constellations having to reposition the telescope every few minutes.
A fast prime lens certainly helps. A typical “kit lens” (budget zoom lens that comes bundled with DSLRs) is typically F/3.5 at the wide end. An F/1.4 lens collects 6 times more light.
Beyond that, the trick is to cover as much sky as possible, and to have the shutter open as long as possible, to maximize the chance of capturing a bright meteor. In the days of film, a typical setup consisted of 4 cameras with 50mm F/1.4 lenses mounted on an equatorial mount, and repeatedly taking images. Exposure time should be the longest you can get that doesn’t wash out the sky.
Obviously that’s a very expensive setup, especially with digital. But if you don’t mind the stars appearing as trails, you don’t have to use an equatorial mount, and you don’t need to limit the exposure time either. If your camera allows it, you can use exposure times of several minutes (if the sky is dark enough that it doesn’t wash out and become white or bright gray).
This is a trade-off. Yes, you can use a low ISO setting and get a very clean image, but with the reduced sensitivity, only an extremely bright meteor would be visible in the image. With a high ISO setting you’ll capture more meteors, but the images will be more noisy.
How long you can expose off a fixed mount before you have visible star trails depends on your focal length. This is a 30 second exposure of the Pleiades at 300mm on a 1.5x crop DSLR. I daresay you can see the effects of the earth’s rotation.
Naturally you’d want a lot less focal length to get shooting stars. I would guess that most really nice shooting star shots are taken from equatorial drive mounts to enable much longer exposures.
I’m a bit puzzled as to why a longer exposure would help, though. Obviously it would increase the chance of a meteor appearing in the field of view during the exposure, but a given meteor is only going to be visible for a short time, less than a second.
All other things being equal, if you set a longer exposure time, you need to reduce the amount of light reaching the sensor (either by stopping down the lens aperture or reducing the ISO sensitivity), otherwise the picture will be overexposed. But that means that short-duration events (such as a meteor) that occur during the longer exposure will have less opportunity to record their light on the sensor, and so will appear faint (or not at all).
In other words, if you expose correctly for 30 seconds’ worth of light from fixed stars, is a half-second meteor streak going to show up at all?
The long exposure isn’t necesary unless you want the background to appear as a backdrop to the shooting star. You’d only need to expose for the half second that the meteor actually appears. Of course, you’d have to be lucky to catch the shooting star during the short exposure, and the shorter the shutter time the more risk you have of cutting it off while it’s in mid flight.
Long shutter times allow you the greatest chance to catch the path of the meteor in its entirety, and it’s also less obnoxious than hitting the shutter button every second if you lack an intervalometer which most cameras do. It’s also much more interesting to have them up against a background than just a black sky with a white streak going across it.
During the pleides this year I tried to catch a shooting star against this background and I almost did - 3 meteors went by that field of view during the night, but always when the camera wasn’t recording. A lot of cameras do dark frame subtraction where after long exposures they shut the shutter and take an equivelantly long blank shot, and any non-black information in the dark frame gets marked as a hot pixel and eliminated from the first real exposure. Which means at most you can only be actually recording 50% of the time. When trying to do lightning or shooting star pictures, I manage to get a remarkably unlikely 80% or so of interesting things to happen during the dark frame subtraction phase…
It’s also possible I did get lucky and catch a shooting star and it simply didn’t have enough light to register.
What camera/lens are you using to do this? Compact cameras simply aren’t that good at gathering light and most are unsuitable for this sort of thing. The shot I linked above was taken with a 1/2.3" sensor with a 3.1 lens at a 30 second exposure - it only came out reasonably detailed at all because the moon was extremely bright and it’s a remarkably bright (for its sensor/lens) backlit cmos sensor. But generally it’s unsuitable for night photography like that. Most compacts are significantly worse in that regard.
Another tip (if you can’t cover the entire sky) is to aim off to the side of the radiant (of that particular meteor shower), preferably between the radiant and the zenith of the sky. Aiming at the radiant itself will only catch shorter meteor trails, but the further from the radiant, the longer the trails. The zenith (directly above you) will tend have more meteors show up on film because the horizon glow from nearby cities generally drown out the fainter meteors.
Great question! My problem has always been with what I believe is called the breakdown of reciprocity? So many books will loosely explain to leave the shutter open and let 'er rip, but I found it is not that simple (whether capturing star trails or shooting stars).
I understand there’s some rule about the shutter exposure cannot exceed the reciprocal of the film speed, but I never had any luck. The film is always overexposed. Perhaps someone can address how to select the correct film based on this rule?
Are you talking about actual film, or setting the camera iso on a digital camera? They’re designed to be related in a way that makes people used to film speeds understand, but they’re different in terms of what the actual result is.
Reciprocity failure is the reduction of film sensitivity with long exposures. E.g. if you photograph the same (very dim) target twice, first with a 10-minute exposure and F/2 lens, and then with a 40-minute exposure at F/4, the concept of “reciprocity” dictates that the two pictures would be the same brightness. But because film becomes less sensitive at longer exposures, the second picture actually comes out darker than the first.
If your pictures are overexposed, that’s the opposite of what reciprocity failure. As beowulff said, you just need a darker sky. Or shorter exposure.
Hey, I was set up in a snowbank to shoot the lunar eclipse. The moon shots weren’t long enough to expose the vibration issues, but 30 seconds is a long time to not have anything wiggle when you’ve just shoved your tripod legs into the snow and have no idea if they’ve even hit the ground beneath.
There’s a neat little extra you can do if you are going to shoot still photos with long shutter times and would like to be able to measure the angular speed at which the meteor crosses the sky. You shoot through a chopper - a rotating disk that is half open so you alternately see through it and then not. This makes the meteor trails appear as dashed lines. The spacing of the dashes tells you the speed. This is a method used by professional astronomers. Well, it was, anyway - my astronomy schooling ended well within the film era.
