Sunday, 21 June 2015

Breaking Bad

To learn anything requires you to repeat an exercise in the same conditions and measure your improvements.

In outside photography this can be a problem, because there are so many variables such as the light, the subject, and the position of the camera. even the lens used and the camera settings.

While often you can extrapolate from one photo to another, it is sometimes nice to be in more controlled conditions.

One way this can be done is via indoor photography. Here you can play around to your hearts content, with all sort of parameters while at the same time taking photos of the same subject.

Of course to do this it is great to have a room set apart for your studio. Unfortunately if you have a growing family, you are unlikely to be in that sort of situation, so instead have to work round the ordinary detritus of human life.

In my case this is the garage. Now like most garages, it has been many years since a car was ever parked in it, and we would struggle to even get a bike in nowadays. Needless to say then it is not ideal as studio,since we  have to fight around tools, drink and various large quantities of wood I have collected  over the ages "just in case" I ever decide to start a carpentry business.

However it has a number of qualities which any studio should have. It is out of everyone's way,. meaning I will not be disturbed. Outside light can be shut off if needed, and with a little re-arranging enough space can be had to set up tripods etc.

The project

 I have always wanted to try my hand at high speed photography, and I had a project in mind to achieve this, and this is where the garage came into play.

The project was to record  the breaking of glass.

Now there appears to be two ways to do high speed photography. Either open the shutter at a high shutter speed in strong light at the opportune moment, or leave the shutter open in the dark and fire a flash at the optimum moment(or a combination of both).

Now both of these require am accurate method of triggering at the opportune time, but the former method is likely to be the hardest, since there would always be a lag between shutter press and activation. So I therefore decided to do the latter.

For this I purchased a radio trigger for my flash. This meant that I could position the flash away from the camera with the trigger close to the subject I wanted to take. Also the trigger had a 3.5 mm din socket that would allow me to trigger the flash by connecting two wires together at the correct moment.

Although  this sounds complex, the real difficulty was triggering the flash at the right moment. The idea was to swing a hammer on a pendulum and at the bottom of the arc meet a glass object. At this point I wanted to trigger the flash.

Now there are a number of ways I could do this. A electronic method could be rigged that triggered the flash if a light beam was broken, or on a sound. However to keep it simple I put a bolt on the pendulum that at some point on the arc would hit a hinge, so make electrical contact and fire the flash. The bolt was used so I could adjust it. The hinge's purpose was so that in theory it would only fire once, since the hinge would fold out of the way.

So how did it go? Well initially I was going to try it with bottles, but I found out that bottles are   actually very hard to break, so I substituted them old type light bulbs which proved far more fragile

This is one of my 1st goes.

As you can see, it worked but the flash fired too early, so although the bulb is breaking it is not quite enough to be easily visible.

However this one was far more successful.

Still I think I can do better. For example the bulb holder has mover as the hammer hit, and it is just a few moments too late.  However I have already learnt some important lessons.

1. I thought I would need to do this in total darkness, which made me nervous of swing a hammer on a pendulum in pitch black with me and camera equipment around. However it turns out that if I set a low ISO, dim lighting is adequate.
2. Triggering is harder that I thought. The mechanism at present sit fires multiple times, which means I have to manually close the shutter, before the 2nd flash. Also adjustment is not as easier than I thought, so i will probably need to redesign the  trigger.
3. Glass gets everywhere, so put sheeting under the work bench and have a way of removing the light bulbs from there holder such as pliers.
4. Get a bigger hammer!. Actually securely attaching the hammer to the pendulum is one of the challenges I need to master. At present I user tie wraps, but they tend to come loose.
5. I will need a lot of bulbs.

Still it is promising. I am tempted to make a electric flash delay that would give be more control on when the flash goes off, but we will see. What I do know is that I will need a lot more light bulbs...

No comments:

Post a Comment