Hello dear fellows,
In the last few months, I've been eager to start artificial lighting more seriously and I've been looking around for general knowledge on how to light my subjects correctly. Now, I think the cosmetic part of lighting I can deal with. However, now that I've acquired a pair of light stands and flash modifiers for my speedlites (nothing fancy really, just a pair of small 33'' umbrellas and two brolly boxes, 1 is 33'' and the other 40'') I'm a bit underwhelmed by the light intensity I'm able to achieve. Admittedly, I was expecting those modifiers to be a bit big for a single speedlite. Yet, the 33'' brolly needs to be at about 1m max to have somewhat decent exposure and this seems close to my untrained eye, not much room for composition if I want to avoid seeing the box in the image.
I've mainly tried to shoot in a dark room (light colored walls so stray light is bouncing all over) at ISO 100 and apertures from 2.8 and up. The flash unit is a Sigma EF610DG Super. Supposed to output GN61m at 105mm zoom, but I've mostly tried with the head at the 24mm setting to reduce the hotspot in the brolly. Now my questions are, as the title says:
1 - What zoom setting is best to maximize brightness in a light diffuser?
2 - Is it reasonable to shoot ISO 100 for a single off-camera speedlite?
I've tried some guesswork in playing with the various settings at hand, but since I've not been systematic enough, I did not come to any valid conclusions. Researching the web on those topics also provided me with all and the opposite as an answer. Possibly this post by Neuro was the most helpful I've found, but I'm not sure how this relates to big modifiers (http://www.canonrumors.com/forum/index.php?topic=18529.msg346022#msg346022
). Therefore, I'd be interested in hearing how people around here set-up.