long exposures at night with Digital Rebel

[archaic0]

I'm looking for any suggestions people might have on getting some nice night shots of the stars in motion.

I've been shooting in manual mode, focus all the way out, 35 mm focal length, and going with a bulb exposure using my remote to open the shutter and close it much later.

I have some examples here:

http://www.dvigroup.net/etc/share/night

The jpgs still have the exposure info in them for you to review.

Any tips?

btw... first week with this camera, first real camera (meaning first one that wasn't a point and shoot) so be gentle... *smile*

Thanks in advance!

[archaic0]

I guess I should add that The pictures were all taken at full size JPG mode and the only thing I did to them is to resize them in photoshop down to 1000 width and save them.

[Arctirus]

Your link is 404.

[archaic0]

My host decided to have a hardware failure directly after I uploaded all my pictures...

It's up now.

[another view]

Didn't find your exposure info and would be curious to know what it is. Some of them are pretty "noisy" (grainy) but not bad - I've personally never done a digital exposure longer than 30 seconds. Long exposures are one thing that can contribute to digital noise. Star trails may come out better on film - digital has come a long ways, but film still has it's strengths.

One thing that can add interest is something in the foreground. If I look closely at a couple, it looks like there's a tree on the bottom left. A little more foreground would probably help, and you may want to also experiment with "painting with light". This can be done by manually popping the flash (hit the test button) once or twice at the tree or other foreground object. You can also use a flashlight.

I don't know if this is a problem or concern, but does anyone know if problems can happen with long exposures on a digital sensor? Other than battery life...

[mjs1973]

I don't know if this is a problem or concern, but does anyone know if problems can happen with long exposures on a digital sensor? Other than battery life...

I haven't done anything over 30sec. yet myself so I can't speak from experiance, but I guy in my photo glass had mentioned it to me. He saw a timed exposure of a waterfall that I took and wanted to know what settings I used because he wanted to try something similar. I don't remember what he was using for sure, guessing a Fuji P&S, but he told me that he couldn't go any longer than 10 seconds or so, because the sensor would get to hot. I'm trying to remember this from a couple of weeks ago, but I'm pretty sure that's what he said.

[archaic0]

Well, for the exposure info, you have to save the pictures locally and then just look at the properties of the file. It's all in there under the summary info. (though you may have to click advanced since it's not in the simple view)

As for damaging the sensor, right in the book canon says that I can leave the shutter open as long as I like. The only restriction they mention is battery life that they estimate at 2.5 hours. So if I had a power adapter I'd imagine it might be interesting to do a 24 hour exposure. Though I'd really want to tighten up the arperature I think or else I'd just get a white result... maybe just dusk till dawn would be as long as I'd want to go.

I think that I've been able to figure out though that ISO 100 is definately the only way to go, and the arperature depends on how bright the stars are. The only way to know though is to do test shots to see just what setting works best with the stars you have available at the time. Then I found a pretty good noise elimination method online.

You simply take a shot with the lens cap on for the same durration as the previous shot. you'll get just noise. You then take both shots into PS and on the noise only shot you drop the saturation all the way down and adjust the right most levels slider to the middle or so. You'll get a very defined noise pattern that you then select by selecting the black areas and inversing. Then take that selection to your image layer and apply a dust and scratches filter with settings of 3 and 0. Tada, a big noise reduction.

I've only tested a couple of shots, but it seems to work pretty well.

I'd still like any tips anyone has from their experience and any shots they can share would be great.

Thanks!

[darkman]

I personally still use film for long (bulb type) exposures. Velvia 100f is great and has no color shift like its predecessor. I find the results much more pleasing. It also requires no extra work.

Mike

[mjs1973]

I came across this old thread while looking for some star trail info, and thought I might add this incase anyone is interested. I read a book a while back that mentioned taking star trails with a digital camera. They suggested in the book to take serveral shorter exposures and piece them together in PS or whatever editing software you use, to minimize the digital noise. So instead of taking an hour long exposure, take 120 thirty second exposures, or however many you want, and can fit on your memory card, then piece them together with your computer. I have never tried it, but it makes sense to me.