Well I hate to post the same photo twice, especially in the same week, but in response to my “ask Ron” request, this was the most asked question. More specifically, Dennis Barton wanted to know how many tries it took to capture this image, while Sheri Lyons wondered how the photo came to look like this.
This was created by using a long exposure, in this case I used a 4 second exposure. This long exposure allows the light to be recorded as it moves across the frame. Typically a light bulb appears as a single point of light, but in this case the camera was able to record the light source in a long streak – and that streak represents how much the light traveled during the 4 second exposure. Since this ferris wheel had lots and lots of lights, I ended up with lots of streaks.
It is kind of a fun technique, in fact whenever I see moving lights, my first thought usually is; I wonder what kinds of patterns would be created with a long exposure? Here is another example from this fall at the Alaska State Fair. You can also use a flash light, sparklers or even moving torches at night to actually sorta draw shapes – it can be fun stuff to experiment with.
To answer Dennis’s question – I actually captured this image in the first try, but that isn’t always the case. I was using aperture priority mode. I closed the aperture to f/14 which gave me a 4 second exposure. I thought that was a good starting point, and that I could add or subtract some compensation based upon what I saw on the LCD on the back of the camera. Well this looked fine to me, so I shot a horizontal with the same settings and moved on to the next scene – there were a couple other compositions I was hoping to capture while it was still spinning.
I should add, for long exposures like this, a tripod is mandatory. In addition to a tripod, I usually use the two second self timer, and turn on mirror lock up to minimize any camera shake. Pushing the shutter with your finger can shake the camera a bit, so by using the two second delay, this isn’t an issue.
In addition, most of the noise you hear when you take a photo isn’t from the shutter, but rather the mirror quickly moving up and down as it gets out of the way of the image path. With mirror lockup and the two second delay, the mirror moves out of the way as soon as you touch the shutter, then two seconds later the shutter opens and closes. I actually use these settings a lot – pretty much whenever possible. It may not make a big difference, but it only takes a couple extra seconds, so if it helps at all, it is worth it. Of course for wildlife and action images, the two second delay doesn’t work.
Instead of the self timer, you could also use a remote cable, but I don’t like carrying extra stuff.