People often ask what the difference is between a silver and a white beauty dish. I have heard it said that beauty dishes are designed to be white, and that silver beauty dishes are a marketing department afterthought. Others say that silver dishes are more contrasty, and have more 'snap,' and so have their place in the photographer's studio.
The Maxwell Renderer is quite accurate at simulating the behavior of light. I thought it might be instructive to use the Maxwell Renderer to investigate the differences between a highly polished near perfect mirror-coated beauty dish (which as far as I know does not exist in the market), a typical silver beauty dish, and a white one.
To reveal the light paths, I ran a wall right through the center of the dishes, bisecting them in half like wall sconces. The virtual beauty dishes are ellipsoids - squashed hemispheres. They are not scientifically designed. The light is placed within the dish by eye, not at any special focal point, and no particular brand of beauty dish is being emulated here.
Remember: these are virtual tests. Not real ones. You may, nonetheless find them worthwhile to see.
click thumbnail above to enlarge
click thumbnail above to enlarge
click thumbnail above to enlarge
UPDATE 9/30/2009
Walter Melrose with mola-light.com on Silver Beauty Dishes
"A silver surface is much cooler in colour temperature and tends to add a cyan cast....The silver surface does not allow the light to follow the contours of the reflector as they were intended. Although the silver surface gives the impression of greater output it does not apply to function, our white surface is 90% reflectance and very efficient."
I remember this quote from the primary source, the Mola site, but right now I can only find secondary references to it on flickr and photo.net
Great information.
Thank you for sharing.