Tuesday, March 27, 2012

Shooting hoops with the kids

My oldest son loves to play basketball.  Warm afternoons will often find him out on the driveway with the neighbors and a ball.  He just finished his sixth season of YMCA youth basketball with a second place tournament finish.  These games always pit the photographer against the father, as it's very difficult to follow the game while looking through the viewfinder.  Hence, I only shoot a few games each year for posterity, and simply enjoy the others along with the rest of the parents.  I therefore don't get a whole lot of practice photographing these games.  I did, however, shoot their final tournament weekend (three games).  I got stopped by several parents asking how to make their own shots better, so I wanted to share what I've learned.  It's no coincidence that March Madness is in full swing as I write this.

[Disclaimer:  I'm well aware that this article assumes some familiarity with basic exposure concepts which some people may not have.  I'm sorry, but I had to stay on topic for a post that was already getting pretty long.  The explanation of those concepts must be saved for another day.  Until I write my own versions, Google is your friend.  Speaking of the length, if you just want a quick hit list without the full story, skip to the end.]

Don't bother trying to stop action with a camera phone.
Auto settings: ISO 160, 1/15s, f/2.6, no flash
The biggest problem with shooting indoor youth sports is that they play in dark caves.  In our town, the elementary-age YMCA games are generally played in junior high gyms.  If you're lucky, you might get a high school practice gym.  They're a far cry from the well-lit venues in which the NCAA Tournament is played.  Dark rooms make life difficult for a couple different reasons.

First, it's hard for cameras to quickly lock in focus.  Consumer-grade hardware, in particular, is often happy to hunt back and force through its entire focus range because it can't see well enough to make out the high-contrast edges that distinguish "in focus" from "out of focus."  Wider apertures help this situation by allowing more light into the camera.  A pro with a decent budget would be using an f/2.8 lens to shoot sports in order to give the camera as much light as possible for focusing.  An avid hobbyist might use an f/4 lens, which passes half as much light.  Most consumer-grade lenses can only manage f/5.6 at the long end of their zoom, and that teeters on the boundary of how much light a camera needs in order to focus.  Such cameras will have trouble focusing quickly on moving subjects, and may not focus accurately when they do stop hunting.

From a different game: ISO 6400, 1/180s, f/4, no flash.
Note the blurred feet and the heavy noise that kills sharp
details. Click the following image to see a 100% crop.
The second problem with dark gyms is that they force the use of very noisy (or "grainy," in film lingo), high ISO settings.  Stopping action in sports requires using fast shutter speeds.  You can capture a free throw easily enough at 1/60 of a second, but once the kids start jumping and running, you'll find you need something more like 1/400s to freeze the action and keep their limbs from being blurred.  Obtaining that kind of shutter speed with an f/5.6 lens in the venues where our kids play would require approximately ISO 12800.  Unless you're shooting with a $6000 body, that ISO will be horribly noisy.  You can drop that to ISO 6400, which is considerably better on my Canon 7D body, but the associated 1/200s shutter speed will blur many of the faster-moving objects in the frame (limbs, balls, etc).  If you have to drop down near 1/100s, you may as well stick to photographing free throws and time-out huddles, because action shots will be unrecognizably blurry.

While consumer-grade lenses typically only have apertures of f/5.6 at the long end, more expensive lenses can frequently reach f/2.8.  The aperture refers to the size of the opening in your lens through which light passes.  The smaller the number, the bigger the hole and the more light makes it through.  An f/2.8 lens will allow you to use a shutter speed four times faster than will an f/5.6 lens, or it will allow an ISO one fourth as high, or some combination of the two.  F/2.8 lenses aren't cheap, though.  How badly do you want to get that great shot of junior's game-winning layup?

ISO 6400, f/5.6, 1/90s, no flash
In Av mode, the dark background tricked
the camera into overexposing and using
an even slower shutter speed.
Another big complaint I have with gyms in general is that the color balance on the lights is all sorts of funky.   Heaven only knows what type of overhead lights might be in use, and sometimes those are combined with large banks of exterior windows near the ceiling... the glass in which which may have a color cast that isn't very close to daylight.  If the daylight portion isn't significant and if you're not using a flash, then by far your best option is to set your camera to automatic white balance and pray for the best.  If you're trying to balance any of these environments with a flash, then you've got your work cut out for you.

If your lens has a variable aperture (as most inexpensive lenses do), you'll be able to use a wider aperture for wide angle shots (say f/4) than you would for long, telephoto shots (say f/5.6).  Use this to your advantage to get the fastest shutter speed possible.  Set your camera to aperture priority ("Av" in Canon's user interface), zoom your lens to the widest setting, and set your aperture to its widest setting.  Your camera will now automatically choose the shutter speed it thinks is best at whatever aperture your lens is able to provide, given your current focal length.  Light-colored walls may throw off the exposure somewhat, but it's better than dealing with unnecessarily slow shutter speeds.

Previously, I've tried shooting most of these games using only ambient room light at ISO 6400 in aperture priority mode at the widest available aperture.  See the pair of yellowish images above for one of the best shots I managed in those conditions.  The results are OK, but not great.  Most are a lot blurrier than this image.  Faces lose lots of detail at that ISO, but lower ISO's lose detail to motion blur.  It's a catch 22.

Adding flash to the mix

For the final three-game tournament, I decided to use an on-camera flash.  Not only does a flash add more light to your subject, which allows the use of a lower ISO, but the flash's pulse is considerably faster than your camera's shutter speed, which helps immensely when it comes to freezing action.  You probably can't get away with using a flash from courtside to shoot an NBA game, but the officials aren't nearly so picky at elementary-aged YMCA games.  The only trouble I've had with a ref resulted in me having to move from the baseline off toward one corner of the court so that diving players wouldn't get hurt (these gyms sometimes only have a couple feet between the baseline and the concrete wall).  I wasn't even using a flash at the time.

70mm, f/4, 1/180s, ISO 1600,
toughgreen gel + FL white balance
Anyway, when using an on-camera flash, I managed to maintain exposure settings in the neighborhood of 1/250s (my max sync speed), f/4, ISO 2500.  That's a considerably cleaner ISO than before, and the fast flash pulse froze the action better than a 1/250s shutter speed normally would have.  Of course, your flash only freezes the action if it's noticeably brighter than the ambient room light.  If the ambient light is too bright, you'll still get lots of motion blur ghosting around your flash-frozen image.  I like to set the camera so the ambient is 1 to 1.5 stops darker than it would be without the flash.  This still makes the background a recognizable part of the scene, but it deemphasizes it and allows the flash to freeze the players without as much ghosting.  To see how much light the flash adds to the background, look carefully at the shadows cast by the players on the back wall in these photos.  The light inside the shadows is my ambient setting.

Speaking of ghosting, if your flash allows it, you should set it to "second curtain sync" so that it fires at the end of your exposure rather than at the beginning of it.  Combining flash with ambient will always create a frozen image with a blur following the path of a moving object.  Normally, the blur comes after the flash, which makes the object appear to be moving backward.  Second curtain sync makes the blur come first, so the objects appear to be moving the proper direction.

ISO 2500, 1/250s, f/4, flash. Less noise & sharper
edges, but note the ambient blur above his hand.
Click for a 100% crop.
If I was shooting black & white, I'd have been a happy camper.  However, remember my complaint about the funky color balance with gymnasium lights?  Well, that's the hard part.  Flashes are colored to match bright daylight.  If you use your flash in any environment other than bright daylight, your camera will set its auto white balance to match the flash, leaving your ambient-lit background with whatever color cast is imposed by the room lights.  This is typically some mixture of green and orange.

The solution to this is to place a "gel" (a colored sheet of plastic) over your flash to match the color of the room lights, then tell your camera to expect everything will match that same color.  This enables the entire image (both foreground and background) to be lit by the same color of light, producing a consistent image.  Auto white balance probably won't work here, since your camera knows there's a flash being used and would therefore prefer to use a daylight white balance.  The trick is figuring out exactly what color the room lights are and then finding a gel (or combination of gels) to match.

The gyms I've been in are usually either fluorescent or something resembling mercury-vapor.  Once upon a time, fluorescent tubes meant you could slap a "tough green" filter on your flash and be good to go.  With all the different shades of fluorescents these days, that's no longer the case.  I find myself needing a half green and a quarter green gel more often than the full toughgreen gel, because today's fluorescent lights just don't have as much of a green cast as they used to.  With these gels, the camera's built-in fluorescent white balance setting probably won't cut it, so you'll need to find a white object, photograph it with your lights, and set your camera to a custom white balance matching that test image.

70mm, f/4, 1/180s, ISO 2500,
1/2 CTO gel + 4000K white balance
Other gyms don't have any green cast at all, and bias their color toward the yellow tungsten (incandescent) end of the spectrum.  In this case, I usually add a half CTO or quarter CTO gel to the flash to add some orange tint, then set the camera to 4000K or 45000K white balance (respectively).

They key is to bring a selection of gels and then experiment with the lights when you first arrive in the gym.  Set the camera to daylight WB and shoot a test shot with just ambient room light.  Is it green?  Yellow?  Orange?  Find a camera WB setting that makes the room colors look natural.  Try not to use a custom WB image unless it's your last resort, because it'll be hard to match that with a gel.

Once your ambient light is dialed in, find a flash gel--or a combination of multiple gels--that will produce that same color of light from your flash.  Tape the gel(s) over your flash, and you're good to go.  This process will take a few minutes, so don't show up right at tip-off and expect to get great shots right away.

If you have a pair of studio lights and a white gym ceiling at your disposal (neither of which I did), you could simply bounce a pair of big, high-power lights off the ceiling to light the entire gym.  It works just like my standard party lighting setup, but on a larger scale.  It'll provide much more even, pleasing light than will direct, on-camera flash.  However, the lights will take on the color cast of the ceiling, and you'll burn some serious juice throwing that much light that far for a couple hundred shots.  110V wall plugs are a must.  I've seen this done at a local high school gym with great results.

By the way, this same process works equally well at school programs that take place in these same gyms.  The kids are moving a lot slower, but the rooms are also a lot darker, so the same theories apply.  At least you can use a tripod for those music programs without sacrificing much to motion blur.

Real world examples

OK, so enough theory.  I want to lay out how my setup progressed through each of the games, including what failed, what succeeded, and what changed.

70mm, f/4, 1/250s, ISO 2000,
toughgreen gel + FL white balance
The first gym was lit by overhead fluorescents plus some high, west-facing windows.  The resulting light was about half way between "daylight" and "fluorescent" on my camera's preset white balance settings.  If I set the camera to daylight, everything looked green.  If it set it to fluorescent, everything looked magenta.  The idea setting would have been a custom white balance along with a "half toughgreen" gel on my flash... but I only had full toughgreens.  I chose to go with that gel, giving the ambient background a magenta tint which I'd have to clean up in postprocessing.  It was far from ideal, but the best I could do at the time.

My equipment was my Canon 7D body, my Sigma 17-70mm f/2.8-4.0 lens, and my old-school, manual, Sunpak 544 "potato masher" flash.  I set the camera at ISO 1600, the lens at f/4, and the shutter speed waffled between 1/180s and 1/250s.  I chose that manual flash because it's the big dog in my bag.  I knew it would have the power to reach the other end of the gym without batting an eye.  The down side is that I had to set the flash power manually, so I used 1/8 power for shots at the far end of the court & 1/16 power for the near end of the court.  I was sitting at one corner of the court and tuned my flash for action in the paint, so my 1/16 flash power tended to really nuke the players if I shot them right in front of my seat.  Pity.  I lost a couple good action shots to that.

Players too close = too much flash
For long range shots at the far end of the court which weren't sufficiently illuminated by my flash, I found that the 1/180s shutter speed allowed too much motion blur.  I'd have been better served by keeping the shutter at 1/250s and increasing my ISO to 2000 or 2500 (which I eventually did in a later game).  I could also have bumped my flash power up another half stop beyond 1/8.

The 17-70mm lens was a great range for shooting anything on the near end of the court while seated at one corner.  For action at the far end, 70mm limited me to "landscape" shots that showed the entire playing field.

The high-speed focusing motor on that lens (Canon's "USM" or Sigma's "HSM") makes a world of difference when following fast-moving players.  I set my focus mode to "AF-SERVO," which tells the camera to continually track focus rather than setting it once and the waiting for the next shot.  As long as you keep your subject under your desired focusing point, the camera will keep your subject in focus as they run around the court.  My 7D body has 19 focusing points (vs 9 for the lower end bodies), and it allows me to group together 5 or 9 of them to create a larger focus target without having to use all 19 of them.  I find that this works better than using just the single center point, which is what I normally do.  If you accidentally slip your focus point off the player and onto the background wall, guess what will be in focus when you click the shutter?

Despite the color cast, this game actually yielded the highest percentage of "keeper" shots of the three games I shot that weekend.  They did require a bit of postprocessing, though, and the background still had an ugly magenta tint.

Bare flash + daylight white balance (compare below)
For the second game, I once again used the same 7D body and 17-70mm lens, but I swapped out the manual Sunpak flash for my automatic, iTTL Canon 430EX.  This eliminated the problem of blowing out the light on action right at my feet, but the smaller flash did have trouble throwing light to the far end of the court.  Still, I think this was the better way to go.

There were no windows in this gym, and the overheads were something other than fluorescent.  They cast a light that was quite yellow (a look which was probably accentuated by the floor and wall color).  Since the first game left me dealing with fluorescents, I was in that mindset when I first arrived.  These lights were definitely not fluorescent, so I shot with a daylight WB and no flash gel through the first half.  The resulting shots show good-looking players on a yellowish background.  I couldn't even do much about the background in post, which sucked.

1/2 CTO gel + 4000K white balance (compare above)
At half time, I reevaluated the lighting and decided that it was actually closer to 4000K.  I set the camera WB to that, added a 1/2 CTO gel to my flash, and got much more pleasing background colors during the second half.

I made a couple other changes for this second game that didn't work out so well.  First, I opened up the aperture on my lens to its widest setting, which is f/2.8 at the wide end and f/4 at the long end.  The problem is that my ISO and shutter speed were set to match f/4, so my background tended to be overly bright in the wide angle shots.  I should have forced the lens to f/4 all the time for a consistent background exposure.

Second, because this gym was much larger than the first, I had plenty of room to roam both baselines.  I chose to stay in the middle half of the baseline at whichever end of the court my team was shooting toward (I switched ends at half time).  Alas, I found that this position created lots more obstructions for me, often in the form of a referee doing his job (not mine) or another low post player blocking my view of a point guard.  I got the smallest percentage of keeper shots at this game.  Perhaps that was due to the coach's game plan rather than my location, but I can't be sure.

The gear I brought to shoot the 3rd game
For the third game, I brought the house.  I was tired of not getting any decent shots of the far end of the court.  I have multiple camera bodies, lenses, and flashes, so I decided to bring two complete setups with me--one for near action and one for distant action.  This was the smallest of the three gyms, and I was again confined to one corner of the court, but after the second game, I probably would have chosen to sit there anyway.

The "near action" rig was the same one I used in the second game.  This time, I fixed the settings for both cameras at f/4, 1/250s, ISO 2500 rather than letting the aperture float to f/2.8 for wide shots.  The lighting was the same 4000K, 1/2 CTO setting that I finished with at the second gym.

58mm (AF), f/4, 1/250s, ISO 2500,
4000K WB, 1/2 CTO gel on flash.
Blueish windows would suck on a sunny day!
The "distant action" rig was my Canon 50D backup body, a manual focus Asahi/Pentax Super-Multi-Coated Takumar 200mm f/4 lens, and the Sunpak 544 "potato masher" flash that I'd used in the first game.  Because all of the distant action was about 60-100 feet from me, I could set the flash at 1/8 power and leave it there.  Its 6 AA batteries barely lasted the entire game, finally dying during the awards ceremony.  A freznel lens would have made the flash more efficient, allowing a lower power setting, extending the battery life, and reducing the recycle time.

All told, I think I brought a little under $3000 worth of gear to shoot a 6th grade YMCA basketball game.  Overkill?  Maybe, but that stuff doesn't do me any good sitting at home on the shelf.  Besides, the practice never hurts.

200mm (manual focus), f/4, 1/250s,
ISO 2500, 4000K WB, 1/2 CTO gel on flash
The 200mm lens felt a little too long, but not dramatically so.  I still got some great shots, but I think I'd have liked a 180mm lens better.  Alas, my next step down is a 75-150mm zoom.  Well, that's not quite true.  I have several zoom lenses that cover the 150-200mm range.  However, getting good image quality at a wide aperture was critical, and those other lenses are all too soft at f/4.  Both this Tak 200/4 and the Yashica 75-150/4 look great wide open, and they're unusually easy to focus accurately (they're both manual lenses).  I can't say that about all of my telephoto lenses.  Next season, I'll probably grab the 75-150mm instead of the 200mm.  You can always crop in tighter, right?  I still missed a number of shots due to inaccurate manual focusing on the long lens.  It would have been nice to have a quality AF lens for that, such as Canon's 70-200/2.8 IS.  That requires a bit more coin than I can devote to camera gear right now, so I'll have to make due with the slightly worse results that my $30, 40-yr-old lens provides.

Being able to shoot at both ends of the court certainly kept me busy, and I took twice as many photos as I had in each of the previous games (500 for the weekend).  Wrangling these two cameras was no picnic.  I certainly couldn't keep both around my neck.  I ended up hanging the 7D around my neck and laying the 50D down in my open camera bag on the floor next to me when I wasn't shooting with it.


Celebrating a 2-point victory
So that's the long version of how I spent my weekend.  If you fell asleep part way through, here's the quick summary of what I'll do next time I shoot a YMCA basketball game.

  • Sit at one corner of the court, as it provides the best vantage points.
  • Two camera bodies:  one with a 17-70mm lens for close action and one with a 70-200mm lens for distant action.
  • Use flashes on both cameras.
  • Set the camera white balance to match the gym light, and gel the flash to match that.
  • Set the cameras to the max sync speed (often 1/250s), the widest aperture (f/4, in my case), and an ISO that puts the room about one stop darker than it should be.

Hopefully this will help some of you "basketball moms/dads" get some better scrapbook material the next time your youngling has a game.  I can't wait for soccer season to start:  outdoor sports at mid-day will be a cake walk compared to this.

As always, if you've got more questions or something you'd like to share, please speak up in the comments below.  I always love to hear from my readers.

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