This is just genius! Previously if you wanted to set a custom white balance for your camera you’d have to cart around your own grey card. But some genius had the brainwave to include a translucent dome into the lens cap itself allowing you to use this instead.
Put your camera in custom White Balance mode, snap a photo with this lens cap on, and your camera creates a perfect profile of the actual lighting in front of you and saves you having to do post-processing to correct colour shifts.
At only US$6 its a perfect stocking stuffer for that photography mad friend!
(PS: I’ve nothing to do with Photojojo but just thought this was cool!)