Indoor martial arts photography with on camera flash?

I've been asked to do some photography for Wing Chun, and it is totally outside of my comfort zone as I've never done sports. (I tend to do landscapes, macro, and maybe portraits for friends) I'm trying to figure out the best way to approach my camera setup.


Indoor, very small "dojo", terrible lighting (half are fluorescent, half are incandescent at seemingly random placement)
I had planned on using my 50mm f/1.4 and 17-55 f/2.8.
Was going to try on camera bounce flash with a speedlight and black foamie thing. Do people even use flash for this kind of thing? I clearly am unsure how I should go about this.

I'm not sure what speed is really necessary to "stop" the motion with martial arts.
Flash sync speed is 1/250... will highspeed sync work if I have to go faster than this?

Any tips would be greatly appreciated.

Ask the host if flash is ok, usually not. On camera flash will look pretty bad too. What will you bounce off, what color is the ceiling?

Low ceilings, small room, I think they're just off white colored. Flash is okay. The pictures are for a TV station in China that is interviewing him. He just wants them to look as good as possible.

1/250 should be plenty fast enough to stop the motion, bounce the flash off the roof.

maybe you could bring in one or two construction floods? they get hot, but are very bright and will most likely overpower the mixed lights you have to deal with now. they're very cheap and you or an assistant could turn them off in between fights etc.

Otherwise I'd use two or three flashes or strobes (borrow, rent?) Just with one flash it's gonna be very hard. You could gel the flash for the more prominent kind of light they have, help diminish the influence of the other kind (probably the incandescent)

Maybe you can go there and do some testing and playing around before the session?

The key to flashed photography such as this is to make your camera exposure for the ambient light dark, at least 2 stops below your flash exposure. The fast fire of your flash will stop the motion and the dark ambient will virtually eliminate any ghosting movement caused by the 1/250 shutter speed and ambient light. In this case the poor dojo light helps, just as long as it is enough to allow your autofocus to work quickly. Most DSLRs take 1/2 second to focus at an EV of 5-6 and focus speed drops off quickly as it gets darker. The f2.8 and brighter lenses help the camera focus quickly in dim light and stop down (get smaller in size) to make the exposure.