Would like assistant for early morning session - Pics added

[kayumangi]

Interesting shots Paco. Quick one for the 2nd image (with the blur) from the exif it said 1/250, how were you triggering the flash? Second, Do you think with hyper sync and maybe full power on a mono it would've helped for f/7.1?

[bondarnes]

I believe the motion blur is caused by the ambient light and not flash duration. I don't know of any commonly available electronic flash units with a flash duration much longer than 1/800th second.

You can borrow my D70 next time. It will sync with flash up to 1/500th second

[texxter]

Originally Posted by kayumangi

Interesting shots Paco. Quick one for the 2nd image (with the blur) from the exif it said 1/250, how were you triggering the flash? Second, Do you think with hyper sync and maybe full power on a mono it would've helped for f/7.1?

I was triggering the flash with Pocket Wizards. If I had used the strobe at full power I would have been able to darken the sky more for sure. If I had also used the sync cable I would have been able to shoot 1/320 sec. So lesson learned.

Originally Posted by bondarnes

I believe the motion blur is caused by the ambient light and not flash duration. I don't know of any commonly available electronic flash units with a flash duration much longer than 1/800th second.

You can borrow my D70 next time. It will sync with flash up to 1/500th second

Don, that may very well be, as ambient contributed quite a bit to the exposure. The best electronic flash units can go to 1/12000 second (Profoto Pro-8a power pack)

Edit - thanks for the D70 offer, I am actually looking for a cheap one to buy.

Thanks for the comments!

[jeffro20]

Paco....great shots, I love the results but still dreaming of what that 7am sky could have offered us if our model had not been late. Thanks so much for allowing me to assist you....it was well worth getting up before dawn and worth the drive from south Arlington. I learned several things that will benefit me in future outdoor shoots.

I do have a picture of your lighting set up on the track. I will post it later this evening from home.

Thanks again....for the valuable instruction and terrific breakfast. I very much enjoyed visiting with you.

[timbertoes]

#1 is a simply awesome shot :)

could you have/what your were doing ?

set shutter for 250 for synch, set fstop to meter for the sky, and then the flash power setting for the subject fill ? just not enough flash power for the subject ?

[janikphoto]

Originally Posted by kayumangi

Interesting shots Paco. Quick one for the 2nd image (with the blur) from the exif it said 1/250, how were you triggering the flash? Second, Do you think with hyper sync and maybe full power on a mono it would've helped for f/7.1?

Are you asking, because you think his camera sync max is only 1/200 sec? And a mono light at full power would probably NOT help, since flash duration usually increases as you push a strobe closer to full power. One way to help stop motion blur is to dial your packs all the way down. However, you'll use the amount of light you need, so you'll need to add in several more "dialed down" packs to overpower the ambient light... or, shoot with a camera that syncs faster, so less power is needed.

Originally Posted by bondarnes

I believe the motion blur is caused by the ambient light and not flash duration. I don't know of any commonly available electronic flash units with a flash duration much longer than 1/800th second.

You can borrow my D70 next time. It will sync with flash up to 1/500th second

You are right and not exactly right in your explanation. Some packs have very long flash duration and will still show some motion blur, if the motion/activity is fast enough and the pack's flash duration is long/slow enough. However, you are correct that ambient light can wreak havoc on stopping a subject dead sharp.

I didn't know the d70 could flash sync at 1/500 sec through the sync cord. That is cool to know! However, flash duration comes into play with faster sync speeds, too. Real cheap packs at full power may spread their light across a 1/250 sec time frame and so any camera sync faster than that may actually be a negative on cheap lights. I have no clue what packs he is using, but hopefully they are of good quality.

Originally Posted by bondarnes

I don't know of any commonly available electronic flash units with a flash duration much longer than 1/800th second.

By the way, Alien Bees are a common light source, and they have a model that lists 1/300 sec as its longest flash duration.

[mmuhlenkamp]

The first shot is great, but I LOVE the angle of the second shot. Some fearlessness there, I'd be afraid of getting landed on with those cleats

Awesome work as usual.

[texxter]

Thank you so much every one for the comments and explanations. Jeff, I am looking forward to seeing your picture with the setup.

I don’t have a strong technical understanding in this area, so let me write down what I think and I would welcome corrections and amplifications.

We have to consider two different objectives a photo like this want to achieve: (1) to control the amount of ambient light contributing to the exposure for a more dramatic effect; and (2) to be able to freeze the motion of a moving object, in this case the runner jumping a hurdle and moving quite fast. It may be helpful to talk about these two objectives separately and then discuss how to achieve both at the same time.
In order to underexpose a bright background, say f/8, 1/125 at ISO100, with a controlled depth of field, say f/8, by 2 f-stops, we need to shoot at f/8, 1/500 at ISO100 with flash. This can be achieve by using high speed flash sync, which some flashes support, or using a leaf shutter camera, which supports higher speed sync speed. When using high speed flash sync, there is a drop in power output as the flash speed sync goes up – this can be compensated by using multiple high speed sync flashes.

But if we don’t mind changing the depth of field we can underexpose the ambient 2 f-stops by simply closing down to f/22 – this means that you need a big flash that will produce f/22, perhaps with some modifiers, in this case a beauty dish and grid. This means a lot of wattsec. This is how overpowering the sun is done with studio strobes that don’t support high speed sync.

Let’s now talk about objective #2, being able to freeze motion. This can be done with high shutter speeds when using ambient light only. Flash will only freeze motion, but in either case the shutter speed or flash duration needs to be brief enough to prevent burring. When you use flash you are normally restricted to the highest sync speed provided by the flash. If you use high speed sync with Nikon SB800s you can shoot at 1/2000 sec and you can indeed freeze motion. A single flash at 8 ft with a modifier at 1/500 sec may put out f/4, at best, which means you need 2 flashes working together. But 1/500 sec may not be enough to stop fast motion, so you can use more flashes and use 1/1000.

What if we are using strobes that don’t support high speed sync? If we want to stop motion we’d want the duration of the flash to be very short, and the contribution of ambient to be low compared to flash. This means being able to shoot at 1/250 sec with a flash that produces very short durations –those durations require low power, which means 2 or more strobes may be needed.

So I have to conclude that freezing motion with flash at normal sync speeds of 1/250 sec is very hard to do when the motion is fast and the contribution of ambient light is significant, like more than 20% or so? In my case I could have done a better job by forcing a lesser contribution of ambient to the exposure, i.e., shooting at f/22, and reducing or eliminating the ambient-induced motion blur. I was shooting with a White Lighting X3200 monolight at 1/8 power or less. I read the spec that t.1 flash duration for a single capacitor is 1/1100 sec (unit has four capacitors, but can be set to use only one for 330 ws, instead of full 1320 ws for four) - this confirms Don Barnes' statement that the motion blur is caused by ambient.

[jeffro20]

This is the set-up for the first image posted by Paco.

[Cajungaltx]

Totally amazing...thanks for sharing the lighting info....

[Imagebuffet]

Wow, nice shots!

I wish I could have helped, but even if I had seen this thread before just now, I would have been unable, due to my work schedule. But, feel free to contact me any time. I owe you!