Figure skating/flash question

[tom beard]

I've been asked to shoot some shots of a skater doing jumps so she can study her position in the air. There are two kinds of jumps, a "picture" jump like a split jump where there is a peak of action and the motion is almost still, and a rotating jump where the skater is in constant motion. I'm using a D-90 with a SB 600 flash on the camera. I've looked at both the camera and the flash manuals and can't find specifically how to stop motion. Should I just set the camera on shutter priority with a shutter speed of 250 or 500 with the focus on 3-D tracking and the flash on TTL? Does the "creative lighting system" automatically compensate? Also, if I use high speed continuous shutter release will the auto focus slow down the firing of the flash? Should I use Manual with a high shutter speed and a small aperture with a high ISO setting and the auto focus off. I don't want to waste a half hour of her practice time figuring out how to set up the camera. If I can just get a few single frame shots I'll be happy and can worry about multiple exposures if we have time. I haven't used the flash much and would like to get into the ballpark. Being a nudnick is damned hard work. Thanks, Tom Beard

 

[tirediron]

I'd suggest a little more reading of your camera and flash manuals. First of all, the highest speed you can set your camera to for flash work is the camera's sync speed (In your case 1/250) I believe; this is not an issue, since you'll be using the flash (duration ~1/10,000 sec) to freeze the motion.

The way I would do this is to set your flash for TTL and use either manual or aperture priority. Determine how far away from the performer you're going to be, and then use Depth of Field tables to determine an appropriate aperture; set the ISO as high as necessary, but keep it as low as possible.

I would use single-servo focus since (I assume) your distance from the performer will be more or less constant, and if she's doing jumps/spins, she will be fairly easy to track. Continuous servo focus will slow your shooting down.

Make sure you have fresh batteries in your flash and camera (and LOTS of fresh batteries in your pocket, remember battery life is shorter in the cold) as well as spare memory cards.

All of that aside, why not use a digital video camera and pull stills from that as req'd?

 

[NWK04]

if you're not trying to make great photographs why use a flash at all? Why not jsut crank up the ISO, use a wide aperture (low F number) and snap away.

What lens will you be using?

Also, the D90 has a sync speed of 1/200th. Unless you're on FP mode (see manual).

Good luck, post some pics.

 

[tom beard]

The lighting at the rink is lousy, similar to a high school basketball court although the ice is under-painted white, so I'll probably need a flash to stop rotating action. I'll probably use a 18-105 f3.5-5.6 kit lens. I have a 70-300mm f4.5-5.6 but I shouldn't be more than 15 feet from the subject, so the 18-105 should do it. I'll give it a shot though. Thanks, Tom B

 

[MrBarney]

Tirediron is right - the flash will stop the motion far more effectively in this situation. I would use shutter priority and set the sync speed to 1/250, auto iso and let the camera deal with the exposure, or manual if the light is fairly consistent. I know that Canon's default to exposing for ambient light in aperture priority, I don't know if your Nikon is the same.

Keep an eye on your maximum aperture on those two lenses - you might find the 70-300 can go larger in the 70-105mm range.

Also, consider using second curtain sync so that any motion blur leads to the skater rather than from them.

 

[KmH]

From the SB-600 users manual, pg 88:

Approximate flash duration at various power settings

1/900 sec. at M1/1 (full) output
1/1600 sec. at M1/2 output
1/3400 sec. at M1/4 output
1/6600 sec. at M1/8 output
1/11100 sec. at M1/16 output
1/20000 sec. at M1/32 output
1/25000 sec. at M1/64 output​

 

[tom beard]

Thanks SO much all of you. I had a hunch I was thinking this to death. I looked at a bunch of YouTube tutorials too. You got my train back on the tracks! Tom Beard