In this post, I will try and explain how I made the picture from the most recent Foto Friday, but first I’ll take you through the process and thought evolution.
About a year ago I saw a post on one of my favorite tech blogs about a guy that does light painting and not only made these cool light spheres but also placed them perfectly in some natural setting. I was inspired right away to try and do the same some time down the line. Fast forward to my birthday when I bought a tripod and decided to start experimenting with really long exposure photography, and you get my first attempt at making light spheres.
I thought the technique should be easy enough, so I tied a bike light to the end of a piece of string, and the idea was to swing it around in a circle for a long time.
Not a bad first go, but not what I wanted. The lines appear disconnected and it didn’t really form a nice sphere. The shutter time on this picture was only a minute, but even then I found it both difficult and tiring to try and swing the light around.
My next idea was to try a smaller tighter circle, hoping that I could keep the lines of light together and not wear out my shoulder in the process.
Maybe even worse. The circles were more uniform, but the major problem was that because I was holding the string with my right hand at my side, as I turned around it didn’t really create a perfect sphere. You can see at least two major foci where the light reaches the top and bottom of the circle. I tried a few more times, and got my housemates and sister to try too, but we never really got it to work. I was determined to figure it out, but I needed to think about it a little while longer.
My solution was to create some sort of device to help spin the light around more uniformly. In the picture above you can see an old fence post resting against the picnic table bench. My first prototype device was built with this post, plus a mop handle screwed in to spin like a propeller. I attached an old bike light to the end of the handle and gave it a shot.
This result was much more encouraging, but still not perfect. My main problem was the black hole right in the center. The way I attached the light to the mop handle made it so it only pointed in one direction, so I had to change which way the light was emitting every few turns. Obviously there was a better solution somewhere. Additionally, because I was moving the light every few revolutions, this was my first exposure over 1 min, this comes in at just over 5 minutes. Luckily I have helpful housemates that were willing to hold the shutter open that long, but I was sure that there would be a better solution to this problem too.
You know first thing in the morning, when you are lying in bed drifting in and out of sleep? Well, it was at that moment a few days later that I dreamed up what my light sphere device would really look like. I headed down to Wickes in search of supplies, and found exactly what I needed. Here is the final product:
Three PVC pipes, a black bucket of concrete, a threaded rod, plus some bolts and two LEDs later I knew I had the right design. And all for about 15 pounds. Plus I really enjoy building things, so this was quite fun for me to assemble.
The pipe on the right hand side of the image above is meant to spin around like a propeller. While the other pipe it is connected to via threaded rod is also meant to rotate around inside the slightly larger pipe, thus creating a sphere. If you picture me standing on the left, spinning the propeller and then walking around the bucket in a circle you might be able to visualize what I mean.
I also found a solution to the aforementioned black hole problem in the earlier spheres. The problem was that although I often rotated the bike light around in 4 directions, I never pointed it right at the camera in the Z-axis. My solution was to attach little LEDs right at the end of the pipe so the light was visible from all directions. Plus I bought a 4 pack of these finger LEDs for a pound.
In the week that passed while I was building my device, I also purchased another useful tool, an IR remote for the shutter release. This means that I could troubleshoot the camera settings on my own and not require someone to stand there holding the shutter open for 5 minutes every time. I definitely recommend a remote. Anyway, it was time to test my new contraption.
Excellent. This was just what I was hoping for. You can see that I need to be a little more patient rotating around in a circle in order to get straighter lines, but overall this was an amazing result. And, as a bonus this was taken with the blue LED, but produced a cool red/violet effect that I don’t know enough physics about to be able to explain. All I needed now was a better backdrop than my back garden.
Conveniently, there is a cemetery at the end of my road, so I picked up my gear and headed that direction. (n.b. I would use less concrete in the bucket next time!) It was very difficult to find a spot without bright city lights in the background, but I think I managed to put this together ok. The only thing I would change is to put the sphere in front of the large black bush on the right next time. I was happy with this picture and almost used it as a Foto Friday, but then the snow came and I wanted to try out my new toy with the possibility of reflection from the ground creating a hover effect.
Here is the raw, unedited photo, and I have to say this was the one and only shot I took that day, it was too cold and time for dinner. This is nearly a 6 minute exposure, and because the snow made everything so bright you can clearly see the bucket at the base of my device, and my legs as I circle the bucket. A quick photoshop trick later and no more bucket, plus some cropping for an enhanced effect produced my final product. The shadow from my legs just adds to the hover effect if you ask me.
So there you have it, my first real go at light spheres. I’m excited about what I want to do with it next. I think I’ll try to make the height of the sphere adjustable, and also experiment with different LED combinations. I look forward to taking this thing all over Oxford once the weather is a little warmer, and also look forward to sharing the results.