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Astrophotography

Star Trails

    One of the best ways to get started in Astrophotography, is to take simple unguided 'Star trails' images

Unhampered by expensive tracking mounts, Guide scopes, expensive CCD cameras, makes shooting star trails

fun and easy. It also lets the novice get great results, there first night out, and sets a good foundation, on which

one can build there Astrophotography hobby upon. Along the way, you will learn terms, and techniques, that

will allow you to advance into the more specialized realm of Long exposure tracked images. You have to start some-

where, and Star trails are the way to go. So lets get started...

 

Click on the links below

 

    What you will need to take your first Star Trail Images

    Some helpful hints, that will make your Images better

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What you will need to take your first Star Trail Images

 

1. SLR Camera with a lens

2. Cable Release

3. Tripod

4. A good Dark sky, on a moonless night.

 

Camera - You only need a camera which has a shutter that can be locked open. A 35mm single lens reflex camera, with manual control, including a 'B' Setting, 'B' for 'Bulb' allows one to time and exposure, and is not limited by a preset time on the camera. Old SLR's from the late 70's early 80's are inexpensive, and many have the features required above. Some include : Olympus OM1, Minolta SRT's, Pentax K1000, and many others. These cameras are fully manual, and do not require batteries to work. (see below)

Lens - Wide angle lenses (24mm-35mm) are a good start, longer lenses can be used, but wide lenses, will allow you to compose objects on the ground better, and this almost always makes for a better image. Use what you have, and try different FL's again there are no real rules here. 

Batteries -  If your camera's shutter only stays open by battery power, make sure you have fresh batteries in your camera before getting started.

Cable Release - You need a cable Release to 'lock' the bulb setting open, this is a must.

Tripod - You don't need a tripod. You can use a bean bag placed on a sturdy surface, like the ground, or a picnic table, or the roof of your car. But taking images will be much easer when using a tripod. Test yours before you go out to shoot, make sure you can point it up into the sky, sounds funny, but some Tripod Heads are made for Video, and will not point very high, making some shots hard to take.

Film - You can use any kind of film for star trail photography. The faster the film, the fainter the stars you will record. 100ISO - 200ISO will work if you want to shoot very long star trails, and faster 400-1600ISO, will be better if you want to shoot shorter shots. There is no 'better' Film speed, it just depends on what you want to shoot. 

With the above items, you are ready to go. 

 Some helpfull hints, that will make your Images better

 Back to the Control Room

 

 

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Some helpful hints, that will make your Images better

 

With your gear ready, head to a good dark sky, on a moonless night, and have some fun!

See the links below, to see if tonight will be a good evening for Star Trails 

Click here for a Moon Phase guide

Click here for Clear Sky Clocks

Here are some hints to make your images better.

Shoot in the area around the north star, your images will have the classic star trail look, add some subjects on the ground, trees, buildings, ect. 

Aperture and Exposure - This will be determined by the darkness of your site, and the speed of film you are using and the f/stop of the camera lens. Long shots require a VERY dark sky. 

If you want to shoot really long exposures, then you need a really dark site and a night when the moon will not be up during the exposure.

The first time you go out, try shooting a series of different exposures: 30 seconds, 1 minute, 5 minutes, 10 minutes, 20 minutes, 60 minutes.

For an exposure of 5-6 hours, you can use a slow film, ISO 25 - 100, and an aperture of f/2.8. If you use a fast film for exposures this long, stop the lens down one or two stops.

For shorter exposures, try a faster film at f/2.8, but the shorter the exposure, the shorter the star trail.

If shooting from a site with light pollution, the length of your exposure will be limited by how bright the sky is. You can only find out by doing some test exposures. Stopping down the lens does not really solve this problem, because as you stop the lens down you will record less faint stars, no matter how long you expose for.

It is usually better to shoot the lens wide open, or stopped down only one stop from its maximum aperture for star trail photos. If you want really long star trails and plan to use a really long exposure (more than 1 hour), then use a slower film.

Experiment and learn.

Dew can be a problem, if you are shooting from home, have a hair drier handy, and if things start to get wet (ie, your Lens) use the Hair drier every 15 minutes, to keep it warm, so dew will not form. If you are in the field, special Dew-Removers, made by Thousand Oaks Optical, and Kendrick Astro-systems, are a good Choice. (Powered by 12v batteries, they keep your lens warm, so dew will not form.

Focus - Make sure you focus the lens at the infinity setting. Beware, some of the new autofocus lenses focus past infinity.

The main thing to remember is to have fun, so dress warm, it gets cold standing in the dark for hours on end.

Be sure and bring some Binoculars, or a Telescope, and observe when you are taking the star Trails, once the Shutter is open, you are free to view about the sky. Just don't point a flashlight (even a red one) in the direction of your lens, or forget you are taking a shot (long exposures are cool, but you don't want to overexpose your shot!)

Good luck on your first Star Trails, 

WHT

 

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