Star trail experiment tonight

Never attempted this before...

Anyone have any helpful hints?

I'm shooting 20mm f/4.0 ISO 100 @ 1 hour for the first shot.

It's crystal clear out tonight and bloody COLD (8 degrees)! Hopefully I can get 1 hour battery life.

Wish me luck, I'll report back later!

On account of Mother Nature, the skies have become completely overcast in the last 25 minutes...

Another night I suppose!

to the seashore for the last couple of nights, and it has been perfectly clear. I know for a fact that it's going to be foggy and overcast when the Geminid meteor shower comes around on the 13th though :)

you can get some wild effects. If you get serious about it, I'd highly suggest looking into "image stacking" (basically taking a ton of shorter exposures on a tripod) or dark frame subtraction (this involves a second photo of the same length with the lens cap on, and is available as "long exposure noise reduction" on most DSLRs), as you can start to get a ton of ugly noise from the sensor at those kinds of exposure times.

If you can get away with it - I'd prefer f/8, unless you're using an old manual focus lens with a hard infinity stop, you're going to need some tolerance in your DOF. Photo below was wide open at 2.8, 60s before I got a remote for bulb mode. I wish I could have stopped down, but then I'd have been looking at very high ISO or a shutter speed I couldn't do without a remote.

Also - look into a battery grip. I got a genuine Canon one, used, without the useless AA battery adapter for $30. Then you can have 2 batteries powering the camera.

Almost a year ago, I made my one and only attempt so far at star trails and learned a few things. I tried it at a relatively dark spot but apparently not dark enough. Here's an essentially unprocessed shot:



The settings I used for this shot were f/22, ISO 100, 10 minutes.
The lesson I learned from this is that I really need to try this either in the middle of nowhere or at an official Dark Skies park/preserve (http://en.wikipedia.org/wiki/Dark-sky_preserve). As you can see from the image, there was a fair bit of light pollution, even though I was fairly far from a significant source of light.

If you manage to find a good place to shoot, I have a couple other bits of advice, both concerning the battery. Lithium batteries are less effective when cold. You may want to find a way to keep the battery warm so it'll last longer. The second important thing to remember is that some digital cameras spend a significant amount of time processing long exposure photos after the shutter closes. My camera (Sony a330) has a 1:1 ratio of exposure time:processing time. So, if I left the shutter open for 10 minutes, my camera would spend an additional 10 minutes to process the shot. If the battery dies during the processing time, the entire shot is lost. Maybe do a test shot indoors to get a rough idea of how much battery life is used for a shot of that duration.

One final note: If you have noise reduction, turn it off when using a tripod.

Other than that, I hope you get a clear night (that doesn't become overcast). I look forward to seeing the results and hearing about anything you learn from the experience.

After reading around the internet last night, as far as extending battering life; I am going to try using a neoprene wrap around the body and wrap the lens with a hand warmer with a rubber band to keep the lens warm.

I'm curious, what were you utilizing as a white balance setting in your photos?

Thanks!

I just had the white balance on Auto. Probably not the best setting to use but I was treating the shot as a test. I had intended to go for round two in the summer but it didn't happen so it'll probably be a few months before I try again. I hope you get a chance to shoot some star trails before I do.

Learn how to just take pictures of the stars. The sky may be crystal clear but you need to be in a remote area with no ambient light anywhere near you. You may think that the town 3 miles away isn't throwing off any light to ruin your image, but it is. You can try center weighted or spot metering to compensate for this.

I took this with a compact digital camera. Exposure time is 60 seconds (this camera doesn't "do" bulb) Even though I could see the Milky Way the camera just barely picked it up.



The longest I've gone with a night exposure (non-stars) is 3 hours. Then add another 2+ hours for the camera to process the image. I use a battery grip with after-market batteries. They last longer than the factory batteries. I'm fairly confident I could go 5 hours and still have plenty of battery juice.

I've never tried a star field movement photo. I'd have to travel quite a distance to get away from any ambient light. Cold is a factor. It eats batteries up quicker and I can't recall the number of times the camera shut down on me in extreme cold. Noise is also going to be a problem. When I tried to remove all the noise from the image above the filter wasn't smart enough and it eliminated a few stars in the process.

There are quite a few tutorials around the web. You might want to read a few. Study up on the whole process.

And take baby steps.

Edit: Brain thinks one word but my fingers didn't get the message.

I got a bit of Orion and a passing semi... darn cold and I went in after a few minutes... too cold to get it focused