138mm Letterbox Diopter Strength:2 60" Maximum Height

60" Maximum Height

requiring an increase of 2 stops for normal exposure

reduces ISO by 1/4) ND

1 density gives a subtle fog effect

Maintains greater sharpness and is less affected by highlight-flare than the standard Fog filter

138mm Letterbox Diopter Strength:2 60" Maximum HeightLetter Box Diopters are considered the reverse of the Strip Diopters. An open slot in the center (similar to a slot in a mail letter box) is flanked by diopter glass on either side. These diopters allow you to create interesting effects while experimenting and allow you to achieve varied focus, diffusion and double imaging effects. They come in 15mm and 30mm formats.