Help with flash portraits with black background

I am looking to replicate shots like this where the subject is partially lit via flash on a nice black background.

http://www.doublered.c​o.uk …s/normal_071113​TK0060.jpg

I am having problems getting the exposure correct. It seems that the shot is either way over or under-exposed.

Should this type of shot be taken using full manual mode on the camera and flashes?? Any help on shutter speed, aperture, and flash settings would be greatly appreciated.

Is it possible in a dark room to get the background close to black or is it essential to use a black backdrop.

Gear: 30D, 17-40 F4L, 580EX(master), 430EX(slave)

Easier with a black background and flash on manual. Meter for the face and make sure your subject is far enough away from the background (and side wall, so there are no reflections from the other side).

It is possible with other background colours (even white), but you would have to have a very large room to be able to get a black background in the final exposure.

There is no reason you shouldn't be able to take the shot with the camera in M and the flash units in ETTL using ratios. Your shutter speed and f-stop will control the background to the limit of the flash units. It looks like all the light is on the left...

clarkmarketingservices wrote in post #5742379
I am looking to replicate shots like this where the subject is partially lit via flash on a nice black background.

http://www.doublered.c​o.uk …s/normal_071113​TK0060.jpg

I am having problems getting the exposure correct. It seems that the shot is either way over or under-exposed.

Should this type of shot be taken using full manual mode on the camera and flashes?? Any help on shutter speed, aperture, and flash settings would be greatly appreciated.

Is it possible in a dark room to get the background close to black or is it essential to use a black backdrop.

Gear: 30D, 17-40 F4L, 580EX(master), 430EX(slave)

Use a black or dark background. Place the light to one side of the subject and about 90 degrees relative to the camera. The subject should be far enough away from the background so that none of the light from the flash spills on to the background. If you have problems with the flash bouncing off the wall opposite the flash and spilling on to the background, use a black panel or black backdrop in front of that wall to absorb the light.

This Strobist article should give you a good understanding of the suject.

http://strobist.blogsp​ot.com …12-position-distance.html