The Big Dipper
The Big Dipper constellation over Jackson Lake, Grand Teton National Park. The orange glow you see is light pollution from Colter Bay.
See the awe-inspiring NightScape VIDEO – with one Milky Way after another!
''NightScape'' series style: If I only wanted to capture the stars against a totally black sky and have no landscape features in the foreground, I'd just attach my camera and lens to an astronomy type tracking motor, and expose as long as I wanted (using low ISOs). However, doing this would blur the landscape features, because camera would be following the stars and the rotation of the earth! My goal in this series is to show the stars in a relationship to an earthly landscape feature, and not just do astrophotography.
In my style of "NightScape" photography, I am trying to capture the stars as points of light, not star trails, so my exposure must be very short -- usually less than 30 seconds. This requires very fast and expensive lenses and extremely high ISOs. (The Canon 5D Mark II is one of the best cameras out there for producing a minimum amount of noise at these high ISOs.)
Longer focal length lenses require shorter exposure times: With my 180-degree, full frame fisheye lens I can expose as long as 30 seconds and keep the stars as points (unless the image is enlarge over 12 x 18, upon which the stars appear a little elliptical). A 24mm (84-degree angle coverage) requires that I shorten my exposure to 15 seconds or less. A normal 50mm lenses (45-degree angle coverage) requires an 8 seconds or less exposure! This is because the longer focal length lenses are enlarging the area of the sky you see and magnifying the earth's movement -- requiring even shorter exposure times.
Lens technical problems: The bigger my lens' aperture, the shorter I can expose my images, and the lower I can set my ISO. However, "big" aperture lenses cost a premium, and I've found that unless I stop down at least one aperture stop or more, the coma (spherical aberration) at the edge of my images is terrible -- the starry points of light grow ghostly wings and take the shape of an obtuse triangle!