Details

Place: Blue Creek, OH at the junction of SR 125 and Blue Creek Rd. There’s a flat area with room for us to park and set up.

For those interested in car pooling, suggest meeting at Wendy’s in Williamsburg at 5:30 for dinner and carpool from there.

The purpose of the Meet-Up is to learn the basics of astrophotography, or if you know them, to take advantage of some pretty dark skies not a terribly long drive away

Blue Creek is the darkest sky area you will find within about a 3 hour drive of Cinci. On Friday the sun sets at 7:33, and the moon rises at 11: 25. Astronomical sunset is 9:03, but the seeing will be great from about 8:00 o’clock until 10:30 or so (and good for a while after that if you’re aiming away from the moon).

Note: bathroom facilities are nil at the actual site, so be prepared. There is a gas station within easy walking distance, but they are unlikely to be open into the evening.

Equipment: camera, tripod, and the fastest lens you own. A headlamp with a red bulb is important, because red light doesn’t fry the night vision of yourself or others near you. A 24-70 f2.8 lens will work great. Wide angle lenses such as 14-24 are also good. If you want to try a telescopic lens, that can work, but you’ll pay a price in shutter speed and/or noise. A sand bag to weight the tripod and a remote shutter are both good to have (especially the remote). Bug spray (Deet) may be helpful.

Etiquette for star shoots: Keep things quiet, and avoid any sort of light other than your red headlight. A lot of the fun is just being quiet in the night, open to whatever magic comes along. Note: if your camera has a viewfinder shutter, you’ll want to use it. If someone turns a light on while your long exposure is happening, light can enter through the viewfinder and fog your photo.

Tips: Astro shooting for amateurs is a battle between ISO and shutter speed and focal length. Wide angle lenses buy you more time before the stars develop little comma-shaped tails due to the rotation of the earth. For most lenses, 13 seconds is about the longest you can shoot without star trails. For a 14 mm lens, you may be good for 30 seconds or longer. You can of course shoot for longer than that, but the stars will have tails. If you crank up the ISO, you add noise to the picture, but you shorten your exposure time. It all depends on your lens and the camera, and how they work together. As a rule of thumb, the lower the iso, the clearer the picture — but the fewer stars you’ll capture because it takes a long exposure for dimmer stars to register on the sensor.

You can experiment with this in your back yard and develop a good idea of what will work best with your camera.

Use manual focus. You can pre-focus your lens at infinity and make a mark on your lens housing, or you can do it this way: Crank your ISO all the way up. Use live view if you have it to make any star look as sharp as possible. Lower your ISO to your expected setting, and turn off live view. Try not to move the focus ring again (which can be hard, fumbling around in the dark). Hint: you can do this before sundown if you pick a distant enough object to focus on. But the live view method works very well as the stars are first appearing.

The photo above was an f2.8, 24-70, 13 seconds. ISO 640. It is a composite of 773 frames into photo shown here.