Last night provided a great opportunity to review some of the basics in photographic methods while attempting to photograph meteors from the Orionids Meteor Shower. While I saw a few meteors here and there from time to time, none dashed across the sky where my camera was aimed. While I was not successful in capturing a meteor, I did experiment on taking pictures of stars, more specifically, the three stars of Orion's Belt, or more generally the whole constellation.

Several observation: 1) When attempting to take pictures of stars, urban environments are not so good of areas for photographing heavenly bodies. While it may appear to be dark, there is enough background light to really effect the picture and create (in my opinion) significant distortions. For one, the background light from such sources as street lights makes it difficult to focus on the stars you are attempting to take pictures. An other issue, metering is rendered to somewhat a trial and error game. 2) Need a real good tripod, especially one that allows for the camera to be positions with the lens facing directly above.

With the above said, a basic review of shutter speed, aperture, and ISO, is in order before looking at the pictures I took.

Shutter Speed: The shutter blocks all light from exposing the film UNTIL you press the button. Then it quickly opens and closes, giving the film a brief flash of light. You can control the length of time the shutter remains open by setting the SHUTTER SPEED. Longer shutter speeds = more light and shorter shutter speeds = less light. The longer exposures ( like 1 second ) give much more light to the film than a 1/1000 of a second exposure even though the number may look bigger on the camera.

Examples:

A half second exposure is ONE STOP darker than a one second exposure.

A 1/125 exposure is TWO STOPS brighter than a 1/500 exposure.

A 1/1000 exposure is THREE STOPS darker than a 1/125 exposure.

Shutter Speeds (more light) 1, 1/2, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000 (less light).

You can have the shutter open as long as you like with the bulb setting. It is the shutter speed I used for the star pictures as most of these images were taken with long exposures ranging from 3 minutes to 10 minutes.

Aperture: Before light reaches film, it must pass through an opening called an "Aperture". The aperture is like a pupil. You can control the aperture by setting the "Aperture Opening", also known as an F-Stop. Smaller F-stops numbers = larger openings and larger openings = more light.

Like the pupil in a human eye, the aperture on a camera controls light.

It does so by closing up to restrict light, and opening up to let it through.

Examples:

moving from f16 to f8 is:
TWO STOPS brighter.

moving from f5.6 to f8 is:
ONE STOP darker

moving from f4 to f2.8 is:
ONE STOP brighter.

Aperture settings: f2.8, f4, f5.6, f8, f11, f16, f22

Exposure is about different combinations of shutter and f-stop settings.

If he exposure is made with a wide aperture ( like f2.8 ), then objects farther away from the subject are thrown farther out of focus. This effect is referred to as "depth of field".

if the aperture is small (like f22) then objects in the background (and foreground ) will appear sharper.

ISO is the number that represents the film's sensitivity to light. A higher ISO number indicates the film is more sensitive and requires less light for a proper exposure. It can be said that this is a faster film. For example, 400 ISO Film is more sensitive to light then say 100 ISO Film and therefore requires less time for the shutter to stay open for any given aperture setting.

With this said, I will now show my attempt to taking pictures of the Stars. Let me remind you it was an attempt but sure a lot of fun.

These images were taken from 3:30 A.M. to around 6:30 A.M with a digital Nikon D50. You will notice that pictures with long exposure times show the movement of the stars as the planet rotates and spins.

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