The brief for the exercise was as follows Set up a still-life arrangement, with any object or group of objects. The lighting direction will depend on your subject, and you might like to experiment but, if in doubt, fix the naked lamp more or less overhead, pointing down. (I am assuming that the camera is aimed at a slight angle downwards.)
Using a diffused light source to soften the shadows and highlights take two photographs, one with just the naked lamp, the other with the translucent material held between the lamp and your subject (but out of view). The two exposure settings will be different.
Look at the results, and write down exactly what you see as the differences. Look, for instance, at the strengths (blackness) of the shadows, their extent, and the hardness of their edges. Look also at the highlights, and at the contrast. Finally, was the diffusion an improvement? Record your answer.
To carry out the exercise I hired some time in a studio. I rummaged around the studio to find Items i could use in a still life and then used a single light from above at a 45 degree angle. To soften the light I shot through a translucent reflector the results can be seen below.
I should point out that one thing I did wrong was not having the camera on the tripod, this would have eliminated any doubt that differences in the photographs are down to differing camera angles. The first photo is the "un-softened" direct light shot. We can see that the the shadows are darker and more defined and also the colours are more saturated than in the second shot. In short the first photo has more contrast.
"A light source has high contrast if its rays all strike the subject from nearly the same angle. Light rays from a low-contrast source strike the subject from many different angles. Sunlight on a clear day is a common example of a high-contrast light source." (Hunter, Fuqua and Biver, 2012, p19). The unmodified light source has a more direct rays off light than the diffused light source. It is not only the shadows which are affected by introducing the diffuser, the reflected highlights also differ between the photographs, in the second shot they are larger and with less defined edges.
I have included a shot of the setup (NB offspring make excellent reflector stands)
