x-ray
Veteran
Many people associate Smith with 35mm cameras. Smith began making photos before 35mm cameras were popular. The bare bulb flash was popular for lighting up small rooms. Especially if the room wasn't large, didn't have high ceilings and had several light colored sides. The technique got very popular with photojournalists into the 60s using Graphlex portable electronic flash.
I think Spanish Wake was made in 1951? So, Servo's argument is a good one, I think, given the equipment popular then and the image content.
It's my understanding that Irving Penn invented the soft box technique using Ascor Sunlight Series Electronic Flash heads in a scrimmed grid array. Later the more powerful flash tubes were built into a box with cooling fans. I've worked with these. Having an arm about 2ft away from a 10K w/s (joule) flash head when triggered... burned all the hair off your arm.
The first soft box that I saw and used was in the commercial studio I apprenticed in in 1972. It was about 4 ft x 4 ft and made if steel and took two people to raise and lower it. It had 4K of halogen lights in it as modeling lights or could be used as a color correct soft tungsten light source. There were 2 roughly 44" quartz flash tubes that were hooked to 2 2400ws Ascor power packs. There was no diffuser over the source but the light sources bounced of the interior of the structure which was painted white. It made a beautiful light much different from today's soft boxes