How to use multiple exposures for a star trail photo?
I would like to take 100 or more 30-second exposures of the stars and then stack them on my computer. I have a remote control for pressing the shutter, but how do I take 100 exposures for 30 seconds each? I don't want to manually do it myself, that would be very tedious. I can use a Nikon D3100 or a D600.
Use the intervalometer built into the D600 and program your number of shots into it. Shoot in manual mode at whatever aperture you chose and your 30 second shutter speed(slowest available isn't it?) You'll wear out both thumbs using that remote.
You can search for intervalometers that replace the handset on your remote with a programmable timer (which it is) That gives some flexibility in using "bulb" setting for longer shutter speeds than max 30 second in other modes.
First thing first.
To avoid having black dot in your star trail you will need to turn off the noise reduction on your camera, this will prevent the camera to take another 30 second to process the noise reduction.
To take multiple shot without having to press the shutter every time on your remote control you will need a remote control that allow you to lock the shutter then you will have to set your camera on "continuous shooting".
I suggest you shoot in jpeg quality, this way it's less demanding on the memory tampon.
Once you're done you will have to create a black image using the same shutter speed, you wil need to add the lens cap on the lens. This black image will serve to get rid of the noise.
To stack all your photos together and use the black image you will need the right software.
You can find them here http://www.liquidinplastic.com/2008/06/startrails/
The D600 has a built in intervalometer
Turn Long Exposure Noise Reduction off - for 30 sec exposures you won't need it - nor will you need to shoot a drak frame either. You won't have any noticeable noise from 30 sec exposures.
This is one I did using a D300 (which also has a built in intervalometer;
- that's 129 30 sec exposures