Today we have a Guest blog from one of my Sciencey friends, Dr Paul Woods, who is as an astrochemist in the day time and Photographer by night. You can see some of this photography on his Carbonmade portfolio.
This is the first of a couple of posts detailing Paul’s DIY experiments into time-lapse photography involving a homemade dolly and DSLR camera.
A while ago, you may remember some volcano exploding and bring half the western world to a standstill with its engine-suffocating dust plume. I was fairly affected by that whole thing because 1) I was due to travel around that time, and 2) more importantly, one of my favourite musicians, Brandi Carlile, was due to come over to the UK as part of her European tour, and the whole thing had to be called off. I was devastated. However, there were some good things to come out of Eyjafjallajökull blowing its top — not least the amazing images from NASA satellites and people on the ground taking pictures of the eruption. Some intrepid people even put together time-lapse videos, and one absolutely incredible example of this is below:
I’ve been a fan of time-lapse videos for a while, and have made a few of my own, but this one was particularly novel because the camera is moving. It is sitting on a dolly, akin to those used to shoot movies, and inching slowly along a track as it shoots.
The company that produced this dolly is called Dynamic Perception, and at the time this dolly setup was just a prototype, and they hadn’t made any production models. Their aim was to retail this baby for about $795, which is quite a lot of money (but potentially worth it once you see the amount of control you can get out of this rig). Here’s one of their initial promo videos:
Dynamic Perception have since added more features to the rig, including an Arduino-based controller. Fancy! And way out of my price-bracket, especially if you factor in shipping from the US. So, I decided to see if I could make something to do a similar job, but for significantly less cash. And here’s how I did it…
So, the idea behind this is to produce a system where a DSLR camera runs along a track. The track should be tripod-mounted, and the dolly should move along the track of its own accord, it shouldn’t require someone to move it.
The most crucial things to sort out in this concept, for me, were the track and the dolly.
I spent a while thinking about what I could use for this. Certainly the geared belt system used by Dynamic Perception would be awesome, but they don’t tend to sell those things at your local Homebase or B&Q. Eventually I hit upon the idea of curtain rails. These would be great because they’re relatively lightweight, fairly cheap (especially if you pick them up at a car boot sale or something) and the brackets used for fixing the poles to the wall could be utilised as supports for the moving dolly.
Excellent! Let construction begin.
The dolly and track
I got hold of a 3m curtain rail with associated supports. Three supports came with the rail, and I got an extra one since it would make the dolly more stable on the track (you could potentially make do with three, though). I picked up some strong steel angled brackets from Wickes to support the track (lower picture), and some smaller jointing plates and nuts and bolts from Clas Ohlson, to fit the brackets. I could then put together the chassis of the dolly, and attach the curtain rail supports:
The good thing about using bolts to hold together your dolly is that you can adjust the width of it by adding or removing nuts. This will come in handy for when you come to mount your dolly onto your track, because if the dolly is too wide or too narrow it won’t run smoothly. This will take a little bit of adjustment later. For now, we can bolt our dolly together and sit it on our tracks:
So that you can see what we’re aiming at, here’s a shot of my ridiculously-too-large-for-this-project pistol-grip tripod head sitting atop the dolly. For use, probably you’d want to use a small ball head, or three-way head… but I don’t have either of those!
The next thing to do is put our track together, and for that we’re just going to add steel brackets to either end of the curtain rails, and add a middle support. Here’s one end:
The curtain rails had pre-drilled holes, and so I used the long screws that came with the rails to fix the brackets to the end of the pole. I had to use a penny washer here since the head of the screw was too small for the hole I was screwing through.
Once the brackets are screwed to each end of the two poles, they can be bolted together to make our track. Some minor adjustment can be made at this point to make sure the dolly runs smoothly on the track. I had to remove a nut from each bolt of the dolly:
If possible, it would probably be better to get a single piece of metal (or wood or plastic, even) to support the ends of the track, but I couldn’t find one suitable. However, this method has the advantage of easily being able to split the track in half for portability.
The middle support is a bit more tricky since we can’t screw the brackets directly in to the curtain poles, since this would impede the dolly. So what I did was find some curved wooden edging in Homebase, cut four 1.5″ pieces (with a bread knife… not a good idea!) and stacked these to give some vertical clearance between our supportive bracket and the dolly, which has to pass over the top. This is better explained with a picture (also showing the edging strip):
Again, I’ve used long screws to screw upwards through the brackets (penny washer, again), through my two pieces of wooden edging, and into the curtain rail itself. It’s important that the screw is not so long that it goes right through the curtain rail and protrudes through the top — this would ruin the running of our dolly. If you only have very long screws, of course you can stack the molding three high if needs be.
Alright, we’re nearly there with our track. If you notice in the Dynamic Perception videos, they use a tripod at either end of the track to get all manner of angles (even vertical… which I don’t recommend for this setup!). Now, I don’t have two tripods and even if I did, I wouldn’t want to be lugging them both around with this dolly! To attach the track to my tripod legs I’ve simply used another, smaller, steel bracket. This bracket has a slot cut in it wide enough to accommodate the tripod bush of my Manfrotto tripod (which is 3/8″ diameter), and I can secure it with a nut, as so:
I also attached a similar bracket to the other end of our track just in case. Of course, the height of the tripod legs can be adjusted to get the desired angle. At present, the far end of the track just rests on the ground, but can be propped on a suitable fence/wall/bench/bush/car door when out in the field, if required.
And that’s pretty much it for our dolly and track system. In the next article I’ll explain how to attach the motor which is going to move our dolly along. For now I’ll leave you with a parts list up to this point, where I got the parts, and how much they cost. TTFN
- 300cm wooden curtain pole and extra support bracket (Dunelm Mill), around £20 — try a car boot sale for cheaper, though
- Six angle brackets 140x35x40mm (Wickes), £1.69 ea.
- Two angle brackets 60x38x60mm (Wickes), £1.69 ea.
- Four jointing plates 100mm (Clas Ohlson), £2.99
- Two 45mm-long bolts and lots of nuts to fit bolts (for dolly)
- Three 35mm-long bolts and appropriate nuts (for track)
- Six M6x30mm penny washers (Wickes)
- Strip of beech edging (Homebase), 50p
Part II of this project will follow soon :)