One of the reasons why I bought a 14mm prime lens was to take photos of the night sky with the stars, planets and galaxy’s in them. I like the wide shots of the sky with the stars and their colours of the Milky Way Galaxy (our own galaxy that we live in) simply becuase these shot are so easy to do–or so I thought. Within the openness of our night time shy there are millions of objects through out it that can be photographed, and with enough time, good optics, and a sensitive enough sensor, one can exposed these objects with really tight detail, just like in the Astronomy Magazines. But, all of this is a learning curve, and a hobby that needs specialized equipment with some money behind it.
Where to look
This is be far the most important part of the whole process, knowing where to point your camera. I use a free piece of software called Stellarium, which is free and open source and runs on all native O.S. Try it, it is a really cool astronomy tool; yes it has pictures!
Telescope: yes or no
Objects such as the Milky Way are so big, that they cover most of the sky. The problem is that the light is so dim for our eyes that we miss them, or only see hazy patches of light. It is when you shoot them with your digital camera, and crank up the sensitivity of the camera’s sensor that you start to see the details. You lenses are important too. You do not need a huge telescope to see these object, just really good quality lenses. Also note to that with wide angle lenses you can get away with just a good tripod, but once you get into the 300mm and up lenses, then you will need a tracking mount to keep the image in-line with the object to compensate for the Earth’s spin. If you do not do this, and you shoot long exposures, you will star trails in your shots.
I use the “divide by 600” rule becuase it works with my stuff, and would work for most of you. This means that if I use a 14mm lens on my “APS HD CMOS sensor (23.4 X 15.6mm)” then I first multiply “1.5” by 14 to get 21. Then divide by 600 (600 / 21) to get my exposure time in seconds before star trails become noticeable in my shots. So I could go as high as 28 second exposure using my 14mm lens. Also note too that if you are using a full frame camera, you would not need to worry about the multiplying by 1.5 for your lens, as the 14mm lens is already calibrated based on a full frame camera anyway.
Where I live, light pollution is a problem. Next to light pollution, are clouds and man made air pollution, coupled with heat rising. You only get one or two really good nights per month where you will have the minimum of atmospheric interference possible to get really good quality shots.
Last night was not one of those good night to shooting the sky, and all of its wonders. I was competing with haze, light pollution and my cheap camera. I think next week, if our weather holds, I will use my larger camera. I am buying ($800.00) a Carl Ziess next week, 14 to 50mm zoom 1.5, and that should clear things up a bit!