Tuesday, August 27, 2013

Beach Volleyball with the Nikon D7000 and Tokina AF 50-135mm f/2.8 AT-X Pro DX

Over the weekend us locals  were treated to some pretty high level volleyball action out by Spanish Banks with the 2013 Beach Volleyball National Championships. The weather ending up being a bit mixed on the day that I was there with my camera, but it was otherwise the quintessential sunny Vancouver beach weekend throughout the tournament.

When I first started shooting as a kid, I was very hesitant to take my camera to the beach. As I've grown older and less wise, I basically stopped caring. When you're done with beach shooting there's sand and dust everywhere, but all you need to do is:

  • Don't swap lenses when you're out on the beach. The sand get's everywhere
  • Take an air-bulb and dust off the nooks and crannies on the outside of the camera
  • Wipe down the outside of the lens and camera with a slightly damp microfiber clothe
  • Use the air-bulb to dust off  the front element of the lens
  • Clean the front of the lens with a new microfiber clothe and some cleaning fluid
  • Open up the camera and dust, flip the mirror and dust off the sensor. There probably won't be much of consequence if you followed the first bit of advice.

Five minutes later, you're done; good as new. No need to worry about the sand gremlin chewing your camera up from the inside.

As I've written before, the Tokina 50-135mm  is a definite favourite of mine, but being an old AF-D screw-drive lens, it's more of an social event lens than a sports lens. The AF is fast enough for sports, but it tends to produce less keepers than if you are using a modern AF-S lens. The other two weaknesses of this lens is that it's good at 100mm, but it is mere adequate at 135mm. It's also quite prone to flare and ghosting if you point it into the light. I heartily recommend buying a used copy if you run into one, but never take one unless it also has the accompanying lens hood.

The D7000 is certainly up to the job for sports, but it's no D300s. A common gripe about the D7000 and D7100 is that the buffer is too small for burst shots. While I agree that it's an issue, for the most part it doesn't have to be. Draining the buffer doesn't help if you capture 1 frame of action and 6 frames leading up to the action; it's better to anticipate and pounce in order to get something like 2 good frames and 2 okay frames. As a non-pro enthusiast, I rarely ever use more than 5 consecutive burst frames because I don't want to pick through hundreds of unusable picturers afterwards in post processing.

What's more important than buffer capacity, and even more important than frame rate, is the reliability and speed of the autofocus system. This is a point that get's lost by the reader's of the camera reviews: even if two cameras have the same autofocus unit they will not have the same performance. The D7100 and the D4 share the same 51-point unit but the D4 uses more computational horsepower to make sense of the data that its AF array is producing. To a lesser extent, that is also true between the D7000 and D300s. The D7000 and D7100 aren't quite the match for the D300s in this category, which is another reason why the D400 has been awaited upon for so long. Check out the "Performance" pages of Imaging Resource's camera reviews for a quantitative difference:

Full Autofocus Auto Area AF
  • D7000:         0.436 s
  • D7100:         0.522 s
  • D300s:         0.370 s
  • Canon 7D:   0.149s (19-point auto)

If you dig deep into the numbers, you'll see that all four cameras have almost identical pre-focused half-pressed shutter times. This places the least amount of computational strain on the camera, as all of the decision making has been taken out of the equation. However, placed in full auto, the camera brain's have more to do, and the difference in response times comes down to the amount of information that the camera has to process, and how much power is available to process that data. All in all, the D7000 and D7100 are significant improvements over the D90 but still fall short of reaching the semi-pro level of AF performance and reliability. In other words, you can expect more spot-on shots with the 7D than you would with the D7000. For my own needs, reliability of focus is number one on my lists of wants, much more so than resolution, and even more than dynamic range and high ISO quality.

However, a dirty little secret of great sports shots (and great shots in general) is to not let anybody see the pictures you threw away. When the action is fast and furious, your keeper rate is not going to be perfect anyway, and for most people it will be quite low.

What helps with shooting sports is getting into a rhythm; sometimes you have to know when to break the rhythm as well. For example, if you always initiate your burst shots at the same moment during serves, you end up getting multiple series of shots that look the same. That means that you'll always be landing shots with the similar facial expressions, or with the ball just at outside of where you want it in the frame. So it helps to know how to vary your shot taking give yourself some variety. However, rhythm is the keyword: the longer you get into it, the more keepers you tend to produce. That was a bit of the challenge of shooting with the women's and men's games alternating on adjacent courts; both sides of the tournament produced some stellar matches, but as a photographer, the faster pace of the men's game required a moment of re-adjustment.

Just another word about the beach. Sand and dust (and smoke/steam in other situations) makes your lens look like crap without any post processing. In person, the swirling of the sand in the air adds to the excitement, but fine particles tend to look like a global loss of contrast in images, and will make it seem as though you are shooting with a cheaper lens than what you have. It's best to back off on the contrast and saturation in Picture Controls and then add it back in during post processing; you can reclaim the contrast with curve adjustments and some careful use of wide-area low-intensity un-sharp masking.

If you have a weaker tolerance for getting sand in your equipment, there's always the option of placing a filter on your lens. A U/V filter would have knocked back a bit of the "blue", but I generally prefer to shoot without any sort of "protection" as it degrades the image quality. In case you are wondering, the overall exposure hasn't been monkeyed with very much in these pictures, so the skin tones and fabric colours are close-ish to be correct. Another option would be for a polarizer to deepen the contrast and saturation. However, I generally find that it's not as necessary if you are shooting with a contrasty lens to begin with; sometimes the circular polarizer can give you too much saturation if that is the case.

It won't always be perfect... great action shot, poor focus in this one.

The demise of the DSLR is being bandied about, but it's not going anywhere. For all of the prowess that mirrorless cameras have accumulated in the past two years, they still can't match DSLR's for shooting moving subjects. Performance-packed (and somewhat affordable) machines like the Nikon D7100 and the Canon 7D were made for having fun on days like this.

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