Center, Center, Center! The Perseus Double Cluster and the moon both came out well, but they were less than ideally centered! Sometimes even when you do center your pictures correctly, the developer can cut the negatives in the wrong place. It's always a good idea to ask the developer if he/she has done astrophotography before, and if not, tell him/her what to look for. Often astrophotos appear "blank" to the developer, because they are so dark. A good way to avoid your negatives being cut wrong is to ask that they not be cut at all, or you can use the first couple of exposures on your roll to shoot normal objects in daylight. This gives the developer a frame of reference.
Star Trails. Notice anything peculiar about these stars? Rather than being perfectly round, they're elongated, or trailed. Sometimes you want stars to trail. But if you hadn't planned on it, seeing trails in your astrophotos will cause you to pull your hair out! The left image was taken with a 300mm lens piggybacked to the LX200. We used the LX200 with a reticle eyepiece to guide the exposure. Any number of things could have happened to cause this image to trail: a guiding error, a bump to the telescope, heavy vibration (footstep, closing door). The right image was not guided at all. Compare this image with the Helix Nebula, which was not guided either. The Helix was a lucky shot; it's always best to guide if possible. The red smudge at the top of the right image is where a red light leaked through to the film. This can happen when you use an illuminated reticle eyepiece with an off-axis guider, or a red flashlight pointed in the direction of the camera.
Planes, trains, and Faint Fuzzies. No, those aren't UFOs lurking in these images. Just pesky planes and red lights. Planes are a big problem with wide field exposures. To avoid these red "train tracks", have someone watch the area of sky you are photographing, or sneak a peek yourself if you're alone. Guiding on wide field exposures isn't as critical, so you can risk taking your eye away from the eyepiece to check. If you see a plane headed toward your field of view, cover the lens with a dark opaque object (most anything will do, even your hand if you're wearing dark gloves), until the plane passes. This doesn't affect the exposure at all. The black smudge on the left image is dust or dirt on the camera lens. Make sure your lens is clean before you shoot, and make sure to use cleaning paper safe for coated lenses. An air blower works well also. The right image is the Andromeda galaxy, a very bright object to your eye, but very difficult to photograph. This exposure is 20 minutes using the LX200 at f/6.3, Kodak Royal Gold 1000 film, and a photographic filter. Even with all that, only the bright nucleus comes out on film. All galaxies are difficult to shoot, and require very long exposures. So choose your targets carefully! In this image another red light has leaked through, in 2 places actually.
Focus! Rain, snow or stars? It's anyone's guess! Focus is critical, especially in prime focus pictures. It's also especially difficult using a regular 35mm camera, because the stars appear extremly dim when doing prime focus pictures. We highly recommend using some kind of focus screen brightener. Orion Telescope Center sells them for a variety of different cameras. The Nikon camera that was used to take many of our photos (courtesy of Don Tabbutt) is equipped with a special eyepiece that magnifies the field of view. It's like looking through a telscope! Also, try not to focus on the stars exactly in the middle of the frame; go about halfway out to the edge and focus there. The moon image here was shot with a Meade ETX, securely mounted on its 3 tripod legs and sitting on a concrete porch (a pretty stable platform!). Either focus problems or vibration caused this image to blur. The "garbage bag" method was not used for this 1/60th of a second exposure, perhaps resulting in the cable release causing vibration. Unless you're taking an astrophoto from an extremly stable mount, it's a good idea to use this method: before starting the astrophoto, even one that's just a fraction of a second, cover the lens with a dark opaque surface (a garbage bag works well). Then start the exposure, wait till the vibration has stopped, then remove the bag. Cover the lens again with the bag before stopping the exposure.
The bottom line with astrophotography is: Something will go wrong. We've ruined countless rolls of film in the past, and no doubt we'll ruin a lot more! Between us, we've: shot an entire roll of blank film of Comet Hale-Bopp; threaded the film wrong so it didn't even advance in the camera, and "shot" 24 pictures of nothing; forgotten to set the camera on "B", so that a 20 minute exposure was only exposed for 1/125th of a second; forgotten to press the rewind button and ripped the film in half trying to rewind it..... The list goes on. But if you're extra careful, you can avoid some of these mishaps, and save that money that would have gone towards a bottle of aspirin to use for more film. Please share your results (and your headaches too) with us!