+ Easy to use, and does a reasonable job of helping to assess the white balance
+ Compared to buying a Colour Temperature Meter, the bargain of the century!
+ More practical to carry than a white/grey card
+ Fitted, it protects the lens
- Having the release buttons at the sides makes it almost impossible to fit the cap when a lens hood is attached
- You'll need to buy a specific cap for every lens that has a different width of accessory thread
- Its grip on the accessory thread can feel less than secure, especially if a shallow filter is already attached to the lens
- The cap is pierced to accept a lanyard, but you… Read more