I'm normally shoot architecture/interiors and commercial product work and I'm expanding into headshots and corporate portraits.
I currently have a couple of 42" shoot-thru umbrellas with blacked out backs to control spill (they're similar to a softbox in that way). I'd like to grab an octo-box for my new headshot work.
Here's my question: is the quality of light from a octo going to be different from the STU at similar sizes. Right now I'm looking at a 36" or a 60" octo. I'm leaning toward the 60" just because I want that great soft wrap around light, but most of the time I'll be on location so that's why I'm wondering if the light from the 36" would be much different from the 42" STUs I already have.
I don't think it would be appreciably different, especially at that size. I'd say use what you have and see how it works. Once you've shot a few sessions you may have a better sense of what you need.
No appreciable difference. Since light quality is a function of the size of your light source (modifier) at the same distance from your subject, compared to the 42", the 36" is only about 15% smaller. I'd definitely go as big as you can manage to get the softest light possible. You may want to explore a 7' parabolic umbrella with a cover. Much easier to set-up and break down for a location gig. https://www.bhphotovideo.com/c/product/866282-REG/Impact_up_7wb_7_0_Para...