Thanks guys for your replies.
Call me dumb !#$% but what is bounce flash and how?
"Too much light makes the baby go blind"
That was a catchy title for a play but it's a bit of an old wives tale.
Although there are real reasons for limiting exposure to light for premature infants, by the time a healthy baby is ready to meet the world, they can often expect to see cameras flashing them at a level that would surprise even Princess Grace.
The warning that came with your flash probably had more to do with the manufacturers own liability concerns than anything else. Still, you should let common sense be your guide. Keeping a respectable distance and using bounce flash will make it easier on the infant and get you better picturers to boot.
Bounce flash simply means tilting the flash head upwards rather than directly at the subject, letting the direct light from the flash "bounce" off of the (usually) white ceiling, diffusing it's output. This will soften the shadows and give a more "open sky" effect to the light from your flash making for a more natural looking photo (and a happier infant). Also TTL metering combined with a wide aperture will limit the output of the flash to the minumum level required for an exposure.
Excessive UV and Infrared are the two components of light from the flash that would be of concern. For IR to be an issue, the flash would have to be in very close proximity. Placing a standard flash so close is something you'd never do to anybody, let alone a defenseless infant! Some flash heads do a better job of filtering UV than others. Very extensive use of a flash that passes a lot of UV has some potential for risk.
I've spent a good amount of time over the years photographing the retina's of infants (and others) in my work using a retinal fundus camera. This type of camera uses a flash illuminator that is coaxial with the optics. This simply means that the flash is directed to shine directly out of the lens, rather than from the side. There is a fair amount of glass between the actual flash tube and final objective lens which eliminates any unsafe levels of UV, but the flash fires at up to 750 watt seconds (300 watt seconds being the norm). The lens is about 1 inch from the front surface of the eye and the effects of the flash are indeed quite dazzling.
Infants (and just about anybody else, including my self) find having this sort of procedure carried out on them to be a bit disagreeable, but it's not dangerous. Of course this the equipment used for this kind of photography is specialized and tested for safety and the procedure is carried out only when it's required for medical diagnostic purposes and isn't approached casually.
In short, infants are probably among the most photographed subjects in the world, and they have been since the days of glass plates and flash powder. As long as you use the flash on your camera as it was designed to be used, there's nothing to worry about.
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Tom Young
http://www.pbase.com/tyoung/ 
