Flash Diffusion material comparison
Well the weather is awful today so I amused myself doing a flash diffusion material comparison. All taken 1:1 with ETTL flash F11 ISO200 1/200th camera in Manual mode, coke-can flash diffuser. I also did a sequence using manual flash settings to estimate the light loss (ie firing at 1/64,1/32,1/16,1/8th) and looking for exposure equivalence in the RAW converter (DPP).
One obvious conclusion is that the "better" diffusion materials lose most light but none apart from the printer paper were prohibitive.
In case you are wondering it's a raisin with two board pins stuck in it