138mm Letterbox Diopter Strength:3 function as a twist on

function as a twist on the stand of the pro halation spill effect

The UV Haze 86 Digital HT Filter is a general use

Superior Quality

6-to-clear is often best for balancing sky to foreground

with a soft-edged transition between the density and clear areas

138mm Letterbox Diopter Strength:3 function as a twist onLetter 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.