Demb Portrait Dish (best flash diffuser rating: 8.50) is a flash light reflector that is designed to be used with hot-shoe flashes. The aim of the design is to provide an alternative to studio umbrellas when shooting on location.
Demb Portrait Dish is one of the largest portable flash diffusers available on the market today. When installed onto a flash, Demb Portrait Dish curves around the flash head. As a result, it creates an approximately 12"x11" light source even though the size of the reflector while flat is 13"x13". The Portrait Dish attaches to a flash head with an elastic band, which length can be adjusted to fit virtually any flash.
Demb Portrait Dish folds flat to about a third of its size (13"x5"). There are two small Velcro patches that keep the reflector folded. They look kind of small for the job, but they hold up reasonably well.
Opening and attaching Demb Portrait Dish may take some practice, but once you are used to it, the reflector can be installed very quickly.
Essentially, Demb Portrait Dish is a huge bounce card with no adjustments. The curvature of the reflector surface helps to distribute the light horizontally. The top flap (hood) drives some extra light forward.
Designed for off-camera work, Demb Portrait Dish can also be used with an on-camera flash, but you would not probably want to walk around with a diffuser that large attached to your flash gun. Below is a sample shot taken with the Portrait Dish on camera.
The images below are taken with Demb Portrait Dish (left) and a 28" studio umbrella (right). The camera is positioned 3-4 feet away from the subject. The diffusers are right next to the camera (single light source, no ambient).
The results produced by a small umbrella and Demb Portrait Dish are comparable although the umbrella creates softer shadow edges. A larger umbrella would certainly give better results, but that is not a fair comparison.
And here is a couple of outdoor shots with Demb Portrait Dish handheld on a 3" cord.Please also note that Demb Portrait Dish is not completely color neutral (slightly warm).
So, when portability is vital for your task, Demb Portrait Dish flash reflector is an attractive alternative to a studio umbrella. It is more compact and portable than even a small umbrella. It attaches right onto your flash gun and does not require any additional mounts. It sets up quickly and easily.