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Did I mention that the new camera has all kinds of manual settings? Last night I gained an appreciation for folks who take photos of astronomical objects. At first I couldn't figure out how to turn the LCD off and was being blinded by it each time I tried to line up a shot. An LCD showing the dead black of night is still way brighter than its subject.
The next challenge: how the heck do you line up a shot? I'm using a cheap tripod without any astral coordinates or even much in the way of stability. It's pretty tough making things out in the viewfinder. I ended up aligning the angle of the camera towards the area of the sky I was interested in, snapping, and hoping.
The photos above are all fifteen second exposures. They are also at F8.0 if that means anything to you (if it does, can you tell me what F to use at night?). The bottom, wider photo is a handheld shot of an airplane passing overhead with it's wing lights blinking at fixed intervals. The oscillation is me being silly trying to hold the camera still, pointed straight up, for fifteen seconds.
The other shots? No idea. I should take notes so I can correlate them. I like the blue donut, it speaks to me, especially with this hot coffee in hand. The blue streak is a mystery and is most likely another handheld shot. The reddish one is surely a rip in the time space continuum enabling a glimpse into a distant, tomato based solar system.
Ted J knows about photos at night.
Welcome to the world of night photography Jerry! I try to take the shortest exposure possible to catch the thing I'm after. The moon, planets and bright stars are all good targets for digital astrophotos. When the exposure is too long, the background noise looks just like a star field, so that's no good.
I use the biggest f-stop I can for the focal length of the lens. The exit pupil of the telescope eyepiece will be the limiting factor, to the f number is the same as for your scope. Stopping down the camera makes alignment more critical with the eyepiece and may even viginette.
And those look better than my first picts (mostly just black or unidentifiable blurs.) You were shooting the Ring Nebula, the Dumbell Nebula and a random meteor, right?
Just to mess us up, the smaller the number, the bigger the opening. f/4 means the opening is 1/4 the focal length of the lens.
You can shoot longer exposures and/or higher ISO ratings in digital if you use some form of noise reduction. This is built in to my Coolpix 4500, but you can also perform it with Photoshop. BAsically, you compare your night image with a second image taken just before or after that one (to duplicate temperature of the CCD) and record an image with the lens cap on of the same duration as the original. Digitally subtracting the lens-capped image from the original removes much of the CCD noise.
Also, exposures for shooting the Moon will generally be similar to shooting a hay field in bright sunlight! (125th @f/16) Don't use your meter. Stars and planets will need to have much longer exposures. Star trails are fun to try if you can keep the exposure going for long enough. I usually use film for that since hours-long shots work best, and I don't know of any consumer digital cameras that will keep the shutter open for that long, let alone have the battery strength!
Thanks for all of the info Chris & Ted. If it ever stops raining here and the night sky returns I'll have to try some of this out.
The Canon A70 when hooked to the computer can be completely controlled: all of the settings, zoom, and taking shots via USB. I'm not sure if this helps at all, but maybe I can "script" my computer/camera to take exposures over a period of time.
Speaking of subtracting to clean out noise. Can you do the same thing to try and cancel out atmospheric perturbations? If I take a few shots of the exact same thing can they somehow be combined to produce a better image?
There are a few deer which visit the field near our house to graze each evening. Zeke and I try to sneak up on them sometimes without any luck.
The owner just finished haying the field tonight so there's not as much forage, but there are these huge hay rolls, which Zeke and I decided to go investigate (pictures later). We're poking around the hay, taking pictures, sniffing things, admiring the hay wrapping tech, having a grand old time.
I look up and there's a deer standing about fifty feet behind Zeke, just staring at us.
Now neither of us had been sitting still up to this point so turning to take a photo really shouldn't have startled the deer. My first shot misfired, so I didn't get the nice one of Zeke and Deer almost next to each other. After that the deer started running and Zeke, still oblivious, decided it was time to head home.
Great second shot and title!