I’m going to be up most of the night working on an (unrelated) project. Every hour or so, I take a five-minute break to get some fresh air and have been taking pictures of the night sky. I’m fairly rural and the moon is gone, so its pretty dark. There are some streaky clouds, but a lot of stars (and Jupiter) are visible.
Since I have just a handful of chances to step outside (and then only enough time to get three or four pictures), I thought I’d ask for any advice as to maximize the ooh/ahh-ness of my shots.
Here’s what I have:
[ul]
[li]Sony Alpha 300[/li][li]8–70mm f/3.5-5.6 lens[/li][li]55–200mm f/4-5.6 lens[/li][li]UV filter[/li][li]Polarizing filter (circular)[/li][li]Tripod[/li][/ul]
Nothing fancy, all pretty much stock.
So far, I’ve experimented with the 8–70 lens, using ‘shutter priority’ mode, turning the exposure time up to 30 seconds, the f-stop to f/4 and toying with different ISO settings. I’ve kept the lens set to as wide a shot as it goes. I held the shutter button halfway and assume it set its focus to infinity. I am not a photographer (please forgive any abuse of terminology), so that’s about the limit of what I know off the bat to change. The camera has a ‘night’ scenic mode, but I don’t know what it does (er, yet). Oh, I’ve also played around shining a flashlight up into the trees to see how things change.
Would taking the time to change to the telephoto lens make a difference? Zoom in or keep it on maximum width? What about the filters? Cutting the exposure time down to less than 30 seconds?
If I had time I’d experiment with all sorts of combinations (and will be doing so if this thread gets no replies), but figured a suggestion or two would cut through a bit of the fiddling. Any ideas?
I think your instincts are mostly good…for general stars/constellations forget the filters or fancy camera modes, use a tripod and manual mode with as wide an aperture as possible and as long as a shutter speed as you can get away with for the focal length before stars start to “streak” (show movement from the earth’s rotation) - you can look up formulas online, or just use trial & error.
The telephoto lens will of course give you a smaller field of view, and will limit the shutter speed you can use before “streaking”…200mm is likely too short for satisfactory moon shots but you can try it, remember a full moon is basically lit by full sunlight so the shutter speed for correct exposure is probably a LOT shorter than you might think.
Of course one great thing about digital (as those of us who grew up shooting film well know) is that it costs you nothing to experiment - for star trails you might try very long exposures, if the camera allows it (“Bulb” mode + remote?) “Light Painting” foreground objects with a flashlight might be well worth exploring…have fun!
The rule for shooting the Moon is to use the same settings you would to take a picture of a rock in broad daylight, because that is after all exactly what the Moon is.
I can pass on what I know from doing astrophotography with a 35mm film camera though I don’t know how that will translate to digital.
The three lenses I had and the maximum exposure times before star streaking was noticeable:
24mm wide angle, about 28 seconds
50mm normal, about 12 seconds
135mm telephoto, about five seconds
I had to use a locking cable release to eliminate camera movement from manually holding down the shutter for those times. And I don’t think you’ll need those filters (I never used them).
Another tip for star trails: For a circular pattern, point the camera at Polaris (the North Star) and the streaks will circle around it. (That’s if you’re in the northern hemisphere; if Shakedown Street is in the south, you’ll have to find the southern celestial pole.)
It should work fine if the camera can make out the pinpricks of light. Still, just set the lens to infinity and you’ll be fine. You don’t need AF to photograph the sky.
I agree. Set the lens to manual focus and turn it to the “infinity” end of the range. Either that, or use your “scene mode” settings, set to “landscape” which will force an infinity focus.
I’d also recommend your shortest focal length (i.e., widest angle of view) that you have available to capture as much of the sky as possible. And your widest aperture (smallest f-stop number, like f/2) to capture as much light as possible; you don’t have to worry about depth of field.
There are others, but these exemplify what I’m getting. I have the camera set to save as RAW and JPG, but the Flickr upload compresses them—I don’t know how much detail will come through. When I use Picassa to do a quick edit/play around with it (Mrs. Devil is the graphic designer in the house; she’ll get a lot more out of them with Photoshop), a lot of detail shows up. A lot of noise, too, but much more detail than is first evident in looking at the black blocks in the Flickr preview.
I’m not sure why in one the fstop went down to 4 while the second would only let me lower it down to 5. Could it be the auto-ISO setting was different for the different skies (the first was actually done last night)?
Oh, for the second picture I turned the camera to manual focus and dialled it to one extreme. I’m pretty sure autofocus did the same thing when it couldn’t find anything to latch on to.
Your second shot looks like Orion, one of my favorite constellations!
As for your f-stop settings, most zoom lenses have different maximum apertures at different focal lengths. So I’m assuming you changed your zoom setting between shots, which changed your maximum aperture (“maximum” aperture being the “minimum” f-number).
The second one actually looks a bit soft (out of focus) to me. You had that set on infinity focus? Also, I’d try to get a stop to two of more light in there.
Shoot manual. Don’t bother with any auto settings for something like this. There is no need or point to do so, and you’ll only frustrate yourself.
I see you’re at 250 ISO. That’s not a bad setting. I like to shoot night with low ISOs and long shutter speeds, but one can start getting star trails at settings approaching a minute. I would bump my ISO to 400 ISO.
Shoot at the widest aperture it allows you. You have a 3.5-5.6 lens there, according to the EXIF. The maximum aperture varies based on your focal length. At the widest setting 3.5 is the max, and at the other end, 5.6. In between those focal lengths, it varies. I would compose my picture, put the camera in manual, set it to the 30 second exposure, and open up the aperture as far as the camera lets me. Take a shot at 400 ISO. Take a shot at 500 ISO. Take a shot at 640 ISO. Take a shot at 800 ISO. Compare your results at the end.
Play around, experiment, have fun. Digital makes this easy, and gives you instant feedback. Keep the camera in manual for this so you have full control of your settings, and adjust them and see what playing around with different settings does to your image. This is how I learned back in the days of film. Take a lot of pictures, play with the settings, understand what you’re doing when you change the settings, and then review. With digital, you could do all the experimenting you want basically for free and without having to wait to get back to the darkroom and develop your film.
:smack: I think the off-focus and the difference in aperture settings is due to inattentiveness–I bet I moved things slightly when moving the camera on the tripod.
Ah, though, the joy of digital imaging and its low cost of mistakes.
In ‘shutter priority’ the wheelamajigger changes the shutter time. Pushing the alternate button (sorry I don’t have its correct name) lets me change the aperture. What other settings is the camera doing automatically? (I can set the ISO to ‘auto’ or a stepped value.)
If I change to M and set the exposure time, aperture, and F-stop, is there anything else to set that would have an effect? I assume things like white balance are irrelevant at the moment.
In my last outing I tried halving the shutter time. I ended up with similar amounts of stars but vastly more noise. Blech.
But all in all, this has been a great success–Tim R. Mortiss actually recognized the constellation; that’s got to count for something!
Aperture and f-stop are the same thing in this context. ISO is the other thing you can change that will have an effect. The technical matters of exposure are a balance between shutter speed, aperture, and ISO.
White balance is a separate issue. I’ve always done star photos with the white balance set to daylight or auto. If you’re shooting raw, it doesn’t matter at all in the end, as white balance information is metadata and does not effect the image capture in any way, and you can change the white balance information after-the-fact with no loss of quality. JPEG is another story. You need to be more careful about white balancing JPEGs. Still, for an application like this, the white balance is not going to be so much an issue with the stars as it is with any foreground lights/glows in your image.
One more tip: Use the self-timer feature on the camera. If you press the shutter button to take the shot, the mere fact of your physical pressure on the camera will cause some amount of jiggle, even on a tripod. But if you use the self-timer, your hand will be long gone from the camera by the time the shot is taken, and the jiggling will have ended. Just an old trick from an old photog!
This is a very good piece of advice. If you don’t have a remote trigger of some sort, the self-timer function can pretty much do the same thing for you, in terms of avoiding extraneous camera shake.
One possibility not mentioned yet (depending on your budget) is to get a fast prime lens. A 50mm f/1.8 lens will give you about two stops of light more than you get with your zooms, and because this is a standard prime lens size they tend to be pretty cheap. This assumes that you are interested in shooting at a 50mm focal length; you might want to try that setting on your current zoom to see if it lets you compose shots you’re interested in.
Some lenses by design can actually be focused a bit “past” infinity, so you may want to experiment before assuming the lens cranked all the way to the hard stop gives you pinpoint in-focus stars.