Under the Stars - Star Fields

[mikej]

Last fall before the rain moved in and kept us covered with clouds, I got interested in Astrophotography. I didn't want to spend a lot of money on it since I wasn't sure how interested I would be and how often I'd be able to go out and shoot. My day usually starts at 5am so I rarely stay up past 11:30 and this kind of stuff takes some long nights to get the really good shots. So I started out the cheap way... my 10D, 24-70 2.8L, tripod and cable release. I found a place within about 15 minutes west of me that is fairly dark, very few cars come by and no real close buildings or houses. And if I don't point towards the East and Portland, the stars can be seen fairly well. I didn't use a tracker for my camera so I was limited to short exposures, around 20 seconds per shot, so I wouldn't get star movement. Without a motorized or manual tracker to keep your camera moving oposite the earth's rotation at the same speed, you will get star movement.

This image uses a technique called stacking. It is 5 images, each taken for about 20 seconds and then all 5 images are layered in Photoshop on top of each other to increase the effective density of the image and remove any hot pixels. A hot pixel shows up as a small red dot and is caused when your digital sensor gets hot from long exposures. Since they are randomly placed, by layering images together, they are over layed and hidden.

Here is one of my attemps...



Here I tried a little bit longer exposure. Even though the stars are brighter, you can just start to see the light points starting to go oblong from movement.



Don't ask me to name the stars, even though I looked them up and knew what some of them are, I forget their names right now.

My experimenting last winter did add to my interest, but it also pointed out to even get half way serious would take some night time dedication and probably about $150 or so to get a decent but cheaper motorized equatorial type mount for my camera so I could get up to 30 minutes or more exposures and do the deep space photography. I also considered getting a telescope that I could mount my camera on, but then I was looking at around $500 to $600 for the lower end of decent telescopes. And then if I spent the money, I'd need to use it, which would require I go at least 40 to 50 miles to set up and not have to worry about being in a farmers field without permission or have someone call the state troopers on this strange guy standing out in the dark with camera.

I'll probably play with it some more this winter when our nights start getting longer and cooler, giving us clear skys... unless it gives us our normal cloud cover and rain. Those that live in the desert areas are lucky in this aspect. Astrophotography is a little harder for those of us in the Pacific Northwest.

Mike

[FocusingOnFlorida]

Hey Mike,

Things are a bit slow around here at the moment. I am digging into some old posts again and found this. Did you get any more photos? I have thought about this in the past when I was still shooting film. I wanted to get the telescope and the adapter but haven't gotten serious yet.

[Bob Stothfang]

Here is a link to a homemade device that might be just what you need:
http://astronomyboy.com/barndoor/

Here is the link to the whole subject:
http://astronomyboy.com/constellations/

Here is a link to another site with a manual model if you want to start simple:
http://www.philharrington.net/scotch.htm