This gallery shows some of the unprocessed results of some lighting tests & modifier comparisons I did a while ago. I was seeking to challenge the maxim that it has difficult to produce portraits with a white background in a small space.

I've left them here in case they're of use to other photographers. Please see the accompanying blog post for more details.
The studioBackdropCamera positionDiffuserGridDeep silver brolly OnlyDeep silver brolly, reflector held flat on lapDeep silver brolly, reflector held just under chinBrolly + wide gridBrolly + wide grid, reflector held flat just under chinBrolly + wide grid, reflector held flat on lapBrolly + diffuserBrolly + diffuser, reflector held just under chinBrolly + diffuser, reflector held on lapBrolly + diffuser,  2 reflector cards held parallelBrolly + diffuser,  2 reflector cards held in V