Bouncing balls, hosepipes and shadow puppets.

This is not an attempt to secure higher rankings by filling the title full of potential seedy euphemisms. I came up with the title when I was teaching a flash workshop this morning and I was trying hard to come up with ways of explaining some very basic concepts regarding the best way to think about how best to use light.

We all know what bounce flash is and most of us use it from time to time. It isn’t a difficult concept to explain either but I have always referred to school science lessons (Physics in my case) when explaining the best way to angle a flash to get the optimum effect. That drew a couple of blank stares today and I had to come up with an alternative (and it appears better) way to explain it. I’m convinced that this isn’t an original concept but I came up with the bouncing ball; simply put, if you stand two people three metres apart (or 2.8 metres for anyone who has ever been to one of my seminars) and one of them wants to bounce a ball to the other and have it reach them at the same height it left at then the optimum point for the bounce is 1.5 metres from the thrower or 1.5 metres from the receiver or exactly half way. The same goes with flash; point the flash at a midway point and you will get the greatest amount of light.

Of course that doesn’t tell the whole story… and thats where the hosepipe comes in. It is entirely possible that bouncing the light at the half-way point isn’t desirable because there is a chance that the angle of the reflector on the flash means that some light will actually hit the subject without having been bounced – light from the very edge of the flash. If you imagine a powerful hosepipe and pointing the stream of water at the wall the water will mostly bounce in the same way that a rubber ball might but the spray of the water will fan out in the same way that flash light does. If your object is to soak the subject, you aim the hose directly at them. If you have to bounce it, then you pick the halfway point. If you want to get them wet without the water going where you don’t want it to go then you pick an aiming point which might not provide the greatest amount of water but will allow you the most control. Obviously, the same goes for light. Direct flash might give you f16 and the halfway point bounce might reduce that to f8 but the nicest light might be a couple of f-stops weaker still at f4 but that might not actually matter.

©Neil Turner, October 2010. Bouncing flash off of a warm-toned brick wall.

©Neil Turner, October 2010. Bouncing flash off of a warm-toned brick wall.

Put simply we are talking about the difference between quantity and quality of light. By deliberately avoiding using the most efficient bounce we often end up with a more pleasing light quality. I often bounce off of walls and surfaces six, seven, eight or more metres away and for that you need to make the bounce as efficient as you can but when the wall is only three or four metres away you have many more options. Suddenly efficiency isn’t the main concern and you can often sacrifice some quantity in favour of quality.

One of my favourite ways of teaching bounce flash is to pick very unlikely surfaces such as wood panelling or brick walls and bounce the flash off of those. Of course you often get a colour caste but a good bit of RAW shooting and/or custom white balancing will sort that out pretty quickly. Above is a sample of a picture shot bouncing the flash off of some yellow-coloured medium toned bricks. It was taken at a University a couple of years ago when I was working on a project with some very cool students.

So what about shadow puppets? Well, we were also talking about creative options and casting deliberate shadows in all sorts of shapes and the best way that I could demonstrate was to throw shadow puppet type shapes in front of the digital projector onto the screen. You can make all sorts of cool shapes from card, through venetian blinds, through windows and doors and even through the back of a wooden chair. If you get the light right, you can do some very creative stuff and all with a basic flash unit off camera.

During lighting workshops I talk about a lot of other stuff but I was amused that in one day I came up with three new ways (new to me that is) of explaining techniques and concepts – techniques and concepts that I normally have no problem describing by referring the school science lessons. Maybe they aren’t teaching science in the same ways that people my age remember any more.


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