Night sky

Last weekend, Lori and Rustin held a birthday celebration for their son at Rustin’s parent’s cottage. It’s an hour and a half out of town so the night skies are stunning. As I’ve written, I was invited to attend. What I haven’t told you was some night photos were on my to-do list.

Night-sky photography is always hit-and-miss. Even with a digital camera, the image you see on the LCD may not really be representative of the photo you have taken. My mistake was forgetting to bring my cable-release. Without it, I was limited to exposures of 30 seconds. Longer exposures will begin to show star trails anyway so not having the cable-release wasn’t an epic failure on my part.

I started with the 50mm f/1.4 but later discovered problems. At f/1.4, the depth of field is so shallow that any focusing error leaves you with a blurry image. Unfortunately, the EF 50mm f/1.4 is prone to focusing errors in low light…just when you want to use a wide aperture. Knowing of this problem, I tried a few wider-angle photos with my trusty 17-40mm f/4 lens. This image below was the best of the lot.

IMG_8143.CR2: 30D, EF 17-40mm 1:4L @ 17mm, 30s, f/4, 800 ISO

IMG_8143.CR2: 30D, EF 17-40mm 1:4L @ 17mm, 30s, f/4, 800 ISO

A few things about this photo:

Tripod? What Tripod? Although I had my tripod, I put that camera down on the dock and used the timer to take the 30 second exposure straight up into the sky.

The black area at the bottom of the image is caused by the trees along the lake shore blocking the stars

Notice the red colour toward the bottom centre of the image, just above the trees? It look like some sort of reflection nebula, but I have no idea if it is. It certainly was not visible to the naked eye.

Look closely and you can see a line of regularly spaced lights from the edge of the trees on the left moving upwards at a 45° angle into the image. These were caused by the flashing navigation and strobe lights of a high-flying aircraft.

The photo came out better than I expected and I’m quite pleased with it, but it’s not what I’d call a good night-sky image. Zoomed in to 100%, it looks like a dog’s breakfast of trails and noise. Even at 17mm, 30 seconds is too long an exposure. It goes without saying that 800 ISO is too noisy as well. The only thing that saved it was reducing its size to fit on the screen. I’ve learned from this image and I’ll do better next time.

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2 Comments

  1. gryan
    Posted September 29, 2008 at 23:49 | Permalink

    impressive. most impressive. there is a star on the photographic horizon. its name is rick pali.

  2. Brent
    Posted October 1, 2008 at 11:20 | Permalink

    I like it! That’s a lot of stars…it could be a record for the most stars in one photo?

    Next time, try stacking the photos to reduce the background noise. You can do this in photoshop if you are patient.

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