On Tue, Jul 23, 2013 at 12:51 PM, Aahz Maruch <a...@pobox.com> wrote: > On Tue, Jul 23, 2013, Bruce Walker wrote: >> On Tue, Jul 23, 2013 at 12:29 AM, Aahz Maruch <a...@pobox.com> wrote: >>> On Thu, Jul 11, 2013, Bruce Walker wrote: >>>> >>>> http://flic.kr/p/f7BHhH Dogwood berries >>>> >>>> Tried my new 30" octa umbrella softbox for macro work; I like it. >>>> Reversed the flash to increase specularity and create more of a >>>> spotlight effect. >>> >>> What do you mean by "reverse the flash"? (Tried quacking but got mostly >>> comic book hits. ;-) >> >> [This is where plain-text breaks down for communicating visuals. I'll >> try ... ] > > You did fine! Thanks! > > Side note: despite my fondness for Lynx, I certainly don't object to > linking to graphic images for explaining something > >> With an umbrella softbox you achieve that by installing your flash >> near the front diffuser, but pointing inward toward the silvered >> insides of the umbrella's central spine. So the light bounces all >> around inside and exits through the diffuser (white scrim) nice and >> soft and even, doubly diffused. >> >> For a different look you can "reverse the flash" by setting it near >> the umbrella spine, pointing toward the diffuser. Now most of the >> light will be concentrated near the center of the diffuser with >> fall-off toward the edges and corners. If you meter the surface the >> center will be 2-3 stops brighter than the edges. In addition, there >> will be some hard specular (directional) light because you no longer >> have a double diffusion effect. > > That's what I would have guessed, but given my functionally zero flash > experience I figured asking was better than guessing. This sounds > functionally similar to just using a diffuser in front of a flash, is > that correct? If yes, is there any advantage to this approach beyond > having your umbrella already set up and it's easier to reverse the flash > than switch to a different flash setup?
The umbrella is almost parabolic and contains most of the light, preventing side-spill. If that's not a concern then holding a diffuser 18" from your flash would get a similar, not identical, effect. -- -bmw -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
