Slow Sync for reception/dance photography

I recently used slow-sync on F100 with 2 Lymedyne 400 lamps about 20

feet on either side of the dance floor. About half of the images are

blurry. I was very upset when I saw this. Is rear-curtain sync a

much better choice for shooting low light dance shots at the

reception? I wasn't sure if the off-camera lights (operated by

PocketWizard attached to camera) would fire in rear-sync mode the

same way as an attached flash would.

 

Gosh, shooting color of dances at the reception is difficult work!

Does anyone have tips, techniques or sample images they can share?

Steve, here's one shot with an F100, lumedyne on camera bracket, shot straight on, and one to camera right, bounced off ceiling. Both are set at 100ws, camera is set at about 1/8 or 1/15, 160ISO film. I use Radio Slave units, one is a Radio Slave II and the others are Radio Slave 4's. Most times, I use the second light to bounce off a ceiling if it is white or mirrored or something close. Or use the second light and feather it across a scene to light up the background. Most times too, I shoot at 1/60 or 1/30 so as not to get too much blurr. Blurr is good and it's bad, just not too much of it. Like everything else in life, everything in moderation.<div></div>

When you shoot with slow-sync don't let the shutter speed fall below 1/60 or 1/30. This

is easy to do if your camera is set to Manual exposure modes.

How slow did you drag the shutter? This was taken during my last wedding. All of the men were circling around the bride singing "My Girl" and dropped to a knee during the main chorus. Shot at 1/30 f5.6 f4 fill flash 400iso

 

 

Could have been better, but not bad.

<cite>Is rear-curtain sync a much better choice</cite>

<p>

No and yes. The only difference between rear curtain sync and

slow sync is that the flash happens at the BEGINNING of the exposure

for slow sync, and happens at the END of the exposure for rear sync.

So if the images were blurry on slow sync, they'd be just as

blurry on rear curtain sync.

<p>

Rear curtain sync does cause the blurry trails from ambient light

to appear "behind" the moving subject instead of in front, so

the appearance can sometimes be nicer. So in this sense, yes,

rear curtain sync can be better.

<p>

To eliminate the blurriness, increase the shutter speed so that

the subject (and camera) don't move enough during exposure to

cause blurs. With a shutter speed that's fast enough to prevent

blurs, there's no practical difference between rear sync and

slow sync.

Hi Steven.

 

If I might suggest, use on-camera flash and get closer. The closer you are the more the

flash duration determines the freezing of the action. If you are using a faster lens, the

background may blur but who cares? It's mostly out of focus anyway. An example of this is

the first image posted below where you can see the foreground subjects are pretty sharp

due to flash duration being so fast, where the background is registering motion blur from

the slow shutter speed (1/15th).

 

Even at a distance on-camera flash has a faster duration than bounced Lymedynes (see

second example shot at a distance using a 550EX on 85mm, without diffusion). Those

larger strobe type flashes have a pretty slow sync speed when used at full power like you

would need to light a whole dance floor. In fact, some older strobe type flash only sync at

1/90th which is why 1/90th is the strobe sync speed on some cameras actually able to

sync at a faster speed. I've shot action in studio with a Mamiya RZ set to a 1/400th sync

shutter speed and the subject still blurred because the flash duration of the strobe at full

power was to slow.

 

Sorry to be so long winded, but the effect of flash duration is not an easy thing to explain.<div></div>

Oops, I inverted the images. The B&W one should be on top in reference to the text. Sorry

I like to experiment, so here are my plays with light/sync recently.

 

The first I shot using rear sync (as Marc said, getting close freezes better) and 1/15 with the flash set (for experiment) to -1 and with a diffuser on the flash.<div></div>

The next I used no FEC and panned with the movement in the foreground (dad and bride). Cam set to 1/40 and @f2.8.

 

Just some ideas. Regards<div></div>

Am a little confused. Seems like you wanted sharp photos with no motion blur. If this is the case, and you had that much flash power at your disposal, you could have set up the Lumedynes to bounce off the ceiling or cross light the dance floor with a medium to medium-fast shutter speed and been OK (no slow sync or slower shutter speeds). The flashes would have done all the work of illuminating your subject(s) AND the background. You could have used manual exposure mode or even program, since 1/60th would have been fine. Slow sync is no good in this situation because the camera would have been trying very hard to expose for the background, setting way too much exposure resulting in pretty extreme motion blur. Rear curtain would be set, as others have already explained, if you wanted your motion blur trailing the direction of movement. Since the off-camera flashes are synced to the on-camera, they would fire when the on-camera fired, even in rear-curtain sync. What shutter speeds were being set by the camera? The trend among PJ style photographers is to show some motion blur (even on the main subject) with very "open" backgrounds. That's when you'd use the technique described above--wide apertures, slower shutter speeds, high ISO so flash duration is pretty short. Usually, with this technique, there are no off-camera flashes.

"When you shoot with slow-sync don't let the shutter speed fall below 1/60 or 1/30. This is easy to do if your camera is set to Manual exposure modes."

 

When you shoot in Manual mode you set the shutter speed, and it will not drop on its own. If you shoot in Av mode the F100 will try to set set the exposure for the ambient light and the shutter speed can drop very low.

 

The amount of blur that you get depends on the shutter speed you use, how fast the people are moving and the ratio of ambient light to flash light makes up the exposure. The higher the ratio of ambient to flash you have the more the movement will register on the film. With the F100, use manual mode to set the aperture and shutter speed. The meter in the camera will give an idea of the ambient light level. If the meter indicates 2, or more, stops of underexposure (ambient level) there will be little motion blur. Ususally when you intentionally want blur/streaks shutter speeds of 1/4 sec are used, but you still want the ambient exposure below the flash exposure to keep every thing from becomiing one big blur.

 

If I'm using lights on stands (room lights), I'll set the level of those lights to a stop under the aperture that the camera is set to and let the on camera flash, in TTL mode, fill in the rest. The radio slaves just transmit when the sync contacts (switch) in the camera closes, and will work in front or rear sync.

"The trend among PJ style photographers is to show some motion blur (even on the main subject) with very "open" backgrounds."

 

That is exactly what I was trying to accomplish. I used two cameras, one with 16mm fisheye and the other with 50mm f/1.4 and both were being exposed at around 1/30th of a second.

 

I never thought to bounce the lumedynes off of the ceiling, I will have to try that. One of the biggest problems I had was the flash exposure aimed directly into the lens and creating undesirable burn spots. So I need to work on angles, too.

 

Marc, In the color dance shot that you posted, you are saying you ONLY used on camera flash? Where is the side lighting coming from in your color dance shot?

Hey Marc,

 

What camera/lens did you use for the color dance shot??

Steven, in answer to your question: Canon 1Ds @ ISO 100, with a 85/1.2, undiffused,

direct 550EX, propped camera on railing of balcony and shot away.

Oh, the side lights were from the 2 sets of videographers working this wedding.

Remember, if you bounce the flashes, you shouldn't be using really slow shutters or you'll get extreme motion blur again since the Lumedynes' sync speed is not so short. As far as light placement to avoid catching your own lights in the shot, if you have two off camera lights, the best thing is to place them directly opposite each other across the dance floor and generally stay perpendicular to the axis of the lights. Obviously it limits you somewhat as sometimes good action happens where you will catch the lights in your frame. You can opt to turn off the off-camera lights with your radio slave controls if you have enough time. If you are using your lenses wide open, you probably will get the "ball of light" effect, which is not so pretty. If you stop the lens down a little, you might get the star effect, which can actually add to the photo. I don't know the actual reason why some lenses/shutters produce the star effect--it has to do with the number of blades in the shutter and stopping down. You might try working with one off-camera flash first before going to two. Also, at some locations it just isn't a good idea to place off-camera lights due to safety/liability issues. You don't want people, especially kids, to trip over the stands or crash into the lights.

Hello Steve,

 

There has been some mention of slow flash duration with your Lumedyne heads. I just checked the specs, at 100ws, flash duration is 1/1600th sec.and at 400ws it is 1/400th sec. Both fast enough to stop action at a wedding, unless the the B&G are realy good Tango Dancers. So I would not worry about any motion effect as a result of your flash equipment, just shutter speed. If you look at the photo I posted above, I rested the camera on the back of a chair to get to 1/8 or 1/15. Just sit in a chair backwards, rest your camera on the seat back, compose the shot, rest your chin on top of the camera or bracket with a little downward pressure and pull the trigger. Good luck.