For those that don't follow strobist

This is pretty sick!

http://strobist.blogspot.com/2009/10/filthy-language-primer-courtesy-chase.html

Such a potty mouth and he shoots with a D3, so it's cool

With Radio Poppers he could have gone all the way up to 1/8000. ;-)

I can understand why a flash would freeze the action is dark conditions, but why don't they get blur when they were doing those sunrise shots? Shutter is open for 1/250, so I would think that here would be movement before and/or after the flash.

The flash is making the shot, not the shutter. Advanced flash photography is really crazy stuff. At least me it is confusing.

I understand that the Flash stops the motion, so if it's completely dark, this technique makes sense. However, they did it at sunrise, so there is light on the subject that I would think would be recorded either before or after the flash as a blur. I'm wondering how that is avoided.

Lots of flash power. Others here can certainly explain better, but I'm pretty sure that they are nuking the ambient light with those flashguns they are use.

At the simplest level, when shooting as they are, you can get rid of ambient light with very fast shutter speeds (and low sensitivity?). You bump your shutter speed up until ambient is underexposed then control the strobed component of the exposure via aperture and flash power.

Like Alan said, it gets confusing when you are pushing the limits as far as these guys. You really need a fast shutter to underexpose ambient, which means you need flash synch speeds that go beyond the 1/250ish that is standard.

Anyway, very cool stuff...and if you're interested in learning more then spend some time on the rest of the Strobist site. Hobby has tons of info there. Also check out McNally's book "Hot Shoe Diarys"

That 'very fast shutter speed' is probably just 1/250th, and they're underexposing ambient by shooting at f/11 or f16.

Chase talks about testing the card speed at 1/250 then mentions that he'll probably be at 500-800 when he's out in the field. Is he not talking about shutter speed at that point? (I'm really asking, not arguing)

So much of the 'strobist way' is controlling ambient with shutter and flash with aperture...so I'm just trying to guess my way though it the way Hobby reverse-engineers the light in so many of his examples. Eh...the absolute numbers aren't as important as the method anyway.

Scott is right with the 1/250th but I would like to know what he was talking about at 500-800 in the field.

Dave...more on the tech's of the shoot here...
http://blog.chasejarvis.com/blog/2009/10/chase-jarvis-tech-strobed-photo.html
http://blog.chasejarvis.com/blog/2008/10/chase-jarvis-tech-high-speed.html

Ok, so let me know if I've got this right. He's shooting at a relatively slow shutter speed (1/250) that would normally blur that type of action. However, he's using the aperture setting to underexpose the photo when the flash isn't present, so any "blur" never gets recorded. The only image recorded is the image revealed by the flash. Is that right?

Yeah, that's the jist of it.

That shoot is taking it to an extreme, there is a middle ground of the same concept that is useful for all kinds of strobe shooting.

Yep, thats right. The D3's maximum shutter sync speed is 1/250.

Chase says:
...1/250th which is the fastest that it syncs. blah blah decent exposure here I think I'm gonna be at about five-six 800 when I'm out in the field"

So, 1/250th, f5.6, ISO 800

David,

Basically you are correct that 1/250th would create motion blur... if the subject was being hit by ambient light. In the situation with the sunset shots they are not being hit by sunlight. The jump is in the shade, causing the rider to be a couple stops less than the sky. This allows the photographer to bring in the subject by flashing him. With lots of light. Make sense? Remember, any part of the subject NOT hit with light will still blur. Even though it will be black due to the fact that it is a silhouette.

Hope that helps!