Freezing high speed action - pre-Wimbledon tennis assignment
This month's assignment for LG Magazine was all about tennis. Wimbledon is fast approaching, in fact I think the qualifying rounds have already started, so the nation's spotlight will once again be on tennis for the next few weeks. I headed to Almondsbury Tennis Club to write a feature piece on their Chairman (chairperson?) Maggie Tyrrell, who is an active member of the Lawn Tennis Association in Avon.
The photography side of the assignment was for three things - some standard tennis shots to go with the article, a cover shot to go with a "spotlight on tennis" subheading, and some stylised, dramatic action shots that will be attention grabbing and look spectacular.
I started with the cover shot, easy enough, straight spotlight on tennis pic (with enough space for mag title and subheads of course):
I knew exactly what I wanted and, unusually, it worked perfectly first time. If only that was the case all the time! I only took four frames in this set up, and to be honest, the last three were only because I felt uncomfortable taking only one frame. But the frame you see is the first shot. Straight out of the blocks the lighting was perfect.
Because later in the shoot I was going to be using Canon speedlites for the action stuff, I used speedlites for the whole shoot. So this is two speedlites side by side, pointing straight down. They're aligned front and back, only about two inches apart. I needed the pool of light to extend a bit in front of and behind the tennis player, because the perspective was going to shorten the pool. So for the light to look round and like a spotlight, and to catch some of the net behind him and some of the front of him, I needed it to be elongated front and back. Hence two speedlites, one behind the other, both side on. You can see what I mean in this photo. You can't see the lights but you can see the pool of light. You can also see my assistant playing on his phone!! Tut tut... rumbled.
Next up was action shots. Here's a very well kept secret... when you're looking into studio strobes, one of the factors you think about is high speed sync (HSS). So naturally we presume that without fancy strobes with HSS, you can't freeze action. But fear not. Cheap, second-hand speedlites are all you need!
Sync speed refers to the time it takes for the camera and flash to talk to each other. I use bottom-of-the-range, super cheap radio triggers - Phottix Ares (recently superseded by the Phottix Stratos). They do not offer high speed sync, so any shutter speed faster that 1/200 and the shutter will open and close before the flash has received the signal to fire.
What you need to know about to freeze action with speedlites is not sync speed, it's T time. At each power setting your speedlite has a published t.5 and/or t.1 time. The t.5 time is the time it takes for the flash to get to full power and back down to 50% power. The t.1 time is the time is takes for the flash to get from 0% to 100% and back down to at least 10%. So essentially the t.1 time is how long it takes to complete its firing cycle, from no light, to full light and back to no light again. Make sense?
I was using two second-hand Canon 580 EX-II's, set to 1/32 power. At 1/32 the "T time" of the 580 EX-II, the time it takes to go from 0 to full power and back down again, is something like 1/5000 of a second. Perfectly good for freezing action. Of course to use the flash though, we're using a shutter speed lower than 1/200, which doesn't freeze action. So, if there is ambient light, and that light is sufficient to make an exposure, you get two images - the frozen one where the flash fired, and a blurred image where the ambient light was lighting the subject over the course of 1/200 of a second, or 1/160 in this case. The result looks like this:
See the racket head? See how I'm getting that ghosting effect? That's the two exposures. There's too much ambient light, so the camera is picking up all of the movement that happens in 1/160th of a second and registering a dark exposure, but getting good exposure for the 1/5000th of a second where the flash fired. Where the racket is bright and well lit, that's where the flash fired. The blurred, dark racket trail is the 1/160 exposure lit by the ambient light. If we had just the flash, we'd only get the well-lit racket, if we had just the ambient light and no flash, all we'd see is the blurred trail.
To give an extreme example - if your camera shutter speed was set to 30 seconds, and there was absolutely no ambient light, you'd get a completely dark image no matter what your subject did in the frame. He could be dancing around, jumping up and down, but there's no light to create an exposure, so it doesn't matter. If you then light one tiny fraction of that 30s exposure time, that's the only thing the camera will see and the only exposure you'll get. So in a perfectly dark room you could have a shutter speed of 30s and still get perfectly frozen action as long as your flash duration was short enough.
Essentially, I needed to set my flash to fire quickly enough to only light 1/5000th of a second, but for the camera settings to be right to register nothing else. All the camera then registers is the moment the flash lights up the subject. And you have frozen action. Like this:
So, to make this work, your camera settings needed to correctly expose for the flash output (in this case 1/160, f6.3, ISO 800) must not pick up any ambient light. So we waited a bit, and the sun went down a bit further, and then everything started to work.
That said, I did accidentally capture quite a cool image while there was still a bit of light:
Interestingly here the flash is firing so quickly that is exposes the ball right at the beginning of the camera's shutter opening, and while the shutter is still open we get another exposure on the tennis ball, caused by the ambient light, which then trails after the flash exposure of the ball. So I went into photoshop and rotated the ball and trail, so that the trail came behind the ball:
Pretty cool right?
I've got two speedlites set up here, one left to right, the other right to left, as you can see by the shadows.
The plan was to roll tennis balls in flour and have our subject (Jeremy), smash it down the court, fire the camera and the flash at precisely the right moment, and get an awesome bullet-from-a-gun effect. Didn't quite work like that. But it created an interesting image:
I don't really like this one. The lighting is too flat and the powder trail from the ball isn't quite right. I had to really boost the exposure on the tail end of the trail as well. Turns out Jeremy was hitting it so hard that the ball left 99% of the flour right at the point of impact.
Anyway, during these shots I had a couple where the key light didn't fire for whatever reason, and between you and me, they looked much better. So rather than flash front and flash behind, firing into each other across Jeremy, I moved both flashes behind and to either side of him. So we've got one flash backlighting him left to right, and another flash backlighting him right to left. Now things started to happen:
Starting to look pretty awesome.
So the next job was to get the timing right. Now it hadn't occurred to me beforehand (duh) that of course with the flashes set to 1/32 power, the recycle time is super quick. I was trying to time single shots bang on the money. But in fact the recycle time was so fast that I could actually just fire off a sequence of shots, starting before Jeremy threw the ball in the air, and finishing after he had followed all the way through his shot.
I started holding down the shutter button and firing a sequence of shots. But of course by now it was really dark, and we couldn't have ambient lighting, or we would start getting trails. So poor Jeremy had to try to serve, not just in the dark, but with two strobes popping at him 7 or 8 times a second. He doesn't have epilepsy, thank god, but it is really something to consider if you're going to attempt this kind of thing!
We moved on from the serves, because they weren't really working. I needed Jeremy to hit the ball less hard. So we tried forehand strokes. My assistant was to throw the balls to Jeremy, and Jeremy had to hit them as cleanly as he could.
Now we revisited the flour trick - ball rolled in flour to created a gun smoke effect... hopefully. With the flour on the ball though, we couldn't let it bounce before it got to Jeremy, or all the flour would come off. So now my assistant had to throw the balls, underarm, and Jeremy had to pick them out in the dark and strike them cleanly, in the centre of the racket, while two strobes were popping at him repeatedly.
You won't be surprised to hear that he missed a couple...
But the team persevered, it took maybe ten attempts to get it right, and it was so so worth all the effort.
Check out the final image:
Keywords: Nick Davis, action, canon, cheap, dark, flash, freeze, havelock photography, night, photo, photography, speedlite, tennis, wimbledon
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