- The wider lens you use the longer your exposure scan be without showing any appreciable movement of the stars. I prefer something about 28mm or wider on a full frame camera such as my 5D Mark II.
- BEFORE it gets dark, focus on something far away to get your lens set to "Infinity". Turn off autofocus and then use a small piece of duct tape (gaffers tape) to fix the focus at that setting.
- Set you camera to long exposure noise reduction. When you take a long exposure, the sensor in your digital camera gets warm and generates noise. Once you close the shutter, the camera will make a second "exposure" without opening the shutter. This builds up another image of just the noise which is then subtracted from the first image. If you are taking a 60 second exposure, your camera will be tied up for two minutes. Get over it.
- USE A ROCK SOLID TRIPOD AND A CABLE RELEASE! Caps to drive this point home.
- Take off the lens hood. Wind will affect the set up more with that "sail" sticking out in front of the lens.
- Make sure your batteries are fresh and have a spare set along fully charged and ready to go. Long exposures eat batteries!
Here are some samples images from the last year or so.
- Exposure should be about 60-90 seconds at ISO 3200
- Lens set at f/2.8 unless your lens will not open that much. At f/4 you will need a higher ISO or a longer exposure.
- NO LIGHTS! If you are shooting with others make sure everyone turns their LCD illumination down as low as it will go. If you have a group, spread out. You don't want your light to ruin someone else's image and you don't want theirs ruining yours.
- Dark skies are a must. No moonlight. Pick a night when there is a new moon or close to it. Nearby towns and farms with yard lights WILL show up. You might not see them with your eyes but the long exposures will certainly enhance them.
- Try lighting foreground objects with small LED flashlights. You don't need much illumination. You will need to experiment with this to know how much is just right.
- Shoot RAW if you can. This lets you make large adjustments as needed including white balance.