Perhaps this topic is already covered, but I would like to learn more about translucent reflectors in studio.

Today, I took some sample pictures using WLX800 with the sport reflector, a.k.a. 11-Inch Long Throw Reflector. In 3' distance I had translucent 42" reflector from Impact. This combo was working like an open softbox.

I don't have a softbox and thus cannot do a comparison. I can see that the effect was different than with the following setups
- 22" BD w and w/o grid
- 64" PLM w and w/o front diffuser
- 42" PLM w and w/o front diffuser
- 42" PLM Japanese Lantern
- normal 7" reflectors with grids.

The question is if the sport reflector with translucent reflector is an alternative for a softbox.

A more generic question is, what are the pros and cons in these different diffused light sources.

In ideal case, I would like to have a diffusion mechanism, which would
- give a nice shape in eyes
- give only one dominant shape in eyes
- would avoid reflections in eyeglasses

A softbox will be infinitely easier to control and position. Using a sports reflector through a silk will give a higher output than a softbox, but every time you want to change the position a bit, you'll have to adjust the strobe and the reflector/holder. The spill will also drive you crazy.

As to your checklist, a softbox can accomplish all those better than that ^^^. For the shape, you can mask off a softbox to yield a perfect circle. And angle of incidence = angle of reflection. Repeat that to yourself until it makes sense.