learning question 420ex flash vs studio

a while ago i posted how excited i was to be able to use two 420ex flashes off camera with a ste2 transmitter shooting with two 60" umbrellas. at that time i shot 1 model.

i just finished my second studio shot, a family of six (unpaid, friends of mine). i was able to take about 2 hours and shot about 150 pictures. same thing, two 420ex flashes and 60" umbrellas.

it was quite a learning experience again, and i did have some success. on some of my shots, especially those using the ratio function to 4:1 or so, the bright side of the faces came out a little hot. well, not the whole face but the specular highlights on the faces.

the umbrellas were close to equal distance apart and that was about 6-7ft from the closest subjects. my question is, i know that the 420ex can't possibly "fill" the umbrella even though the umbrella was as far from the flash as possible, so is that would could cause the hotspots? say vs. a strobe which would fill the whole 60 inches and make the light even softer?

another thought i had was that the family didn't have any make up on, so some of their faces were a little shinny to begin with.

tia

ps i think i'm hooked and wanna get AB800's now that i've done a couple of "studio" shots oh no, here i go sliding down the studio slide!

It's hard to say without seeing a sample image, but my guess is that filling the umbrella more completely would have little effect on the highlights as you describe. The main advantage of using the whole umbrella would be softer shadows.

Shooting the 420EX into an umbrella, there may be some advantage to using a Sto-Fen Omni-Bounce to spread the light out (though I probably wouldn't buy one just for that purpose). Also, there are some diffusion gels that come with the Roscolux swatchbook that might do the job.

i've thought about it a little more and i think it's just a question of overexposure. i think i was trying to correlate the size of the light source with the spreading out of the light across the surface.

here's a sample 100% crop crappy jpg compression. you can see the hotspots on the cheek and nose. so like diffusing the light in a larger circular area wouldn't get rid of the hotspot on the nose for example.