Tuesday, 11 September 2012
Light the bike
What I tried to do here was build a lighting set-up that would be easy to re-create in any forest/woodland situation.
By testing out a basic set-up and taking note of the settings I hoped to give my students a reasonable starting point to work with.
Ok, so let's deconstruct it.
We started with an idea of where we wanted the lights to go. A fill light would be on a lightstand, with a reflecting umbrella, behind at camera right. I was taking a chance with the umbrella on location. Often it's too windy to use. But here in the woods, all was still and quiet.
Next, I put a key light on the ground almost directly in front of the rider, to camera left. The flash was protected inside a waterproof, clip-lid food container, zoomed too 80mm and pushed through a silver-lined snoot to create an intense beam of light.
Finally I put another flash in another clip-lid food container on the ground, just behind the log over which my rider would be jumping. This would push a bit of back-lighting up into the rider as he flew past.
I'll explain the settings and the lighting modifiers I used and my thinking behind them. But first, let's look at the scene before we lit it.
Shooting at f8 for decent depth of field, the foreground ambient is killed off pretty effectively with a shutter speed of 1/250th at 100 ISO.
You might notice that the ambient in the far background looks OK. The sun is shining back there and f8 at 1/250th is pretty standard exposure for a bright sunny scene. I want to kill that foreground ambient because I want the flash to be the only light source on the subject. But I'm happy for tha sunny background light to remain - adds a nice extra layer of light. I may not have noticed this if I hadn't done this simple ambient light check photo so get into the habit of doing this first.
Here's an overview of what I'm trying to do - I ought to have pulled back and shot a frame to show the umbrella stand but I forgot to!
Anyway, I put the lights in place and shot a few frames to test them out for power settings, light coverage and angle. The umbrella would throw a broad soft light over the scene from camera right and I kept the power down so it would act as a fill light not a key light. I think it was set to 1/8th power.
Finally, I added the key light which would be the dominant, feature light. It was placed on the ground just off to one side of the riders line, and zoomed through a home-made snoot. This was a deliberate move to contain the light and not over-light the foreground landscape. I needed to light the rider, not the ground - that would have drawn the eye away from the action too much and it's something I've learned as I've used off-camera flash more and more.
It's not quite as dynamic as I would like. Actually, to tell the truth it's a little dull and predictable and bit too static for my taste. It needs something more. Ooo, I know, how about some motion blur? Oh, and some panning too. Yeah, let's give that a go. Drop the shutter speed to around 1/30th - that means the ambient is going to get a bit bright, might need to loose an F stop or two - maybe f11 or f16 - Ok so that means upping the power output on the flash a bit. But that's no problem with this set-up because I'm using Pocket Wizard Flex TT5's and Mini TT1/AC3 contoller so I just dial up the power a bit from on-board the camera, easy-peezy! If you haven't read up on the PW Flex and Mini system yet, go to http://www.pocketwizard.com/
Ok, so let's recap. For shooting under the trees, you need to test the ambient and find a shutter speed that effectively kills it off so you can add your own lighting with off-camera flash.
That will often mean using the max sync speed and that's good, because if there's no ambient light, your flash guns can operate at low power levels, so fast recycle times and long lasting batteries - great.
Next, we added an overall fill-flash using a light stand and a reflecting umbrella to create a soft, wide light. A shoot-through umbrella will do just as well and if it's windy then leave the umbrella in the bag and just use a diffuser dome.
Next we added a key light shooting through a snoot to project a focused beam of light on the rider. We kept the light off the foreground landscape with this set-up. Placing the light low down allows us to get the light up into the riders face, under the rim of the helmet which would otherwise cast a strong shadow over the face.
Finally, we added the backlight, a crucial addition in my view, by hiding it behind the log.
Then we tested the whole rig for a fast shutter speed - which worked fine - but ultimately decided to get a bit more creative with a slow speed, motion-blur panning shot. So that's all right then.