Hoya HMC ND4 Filter 67mm

Neutral Density filters are often ignored by photographers, but they have several uses and offer the possibility to acheive otherwise unacheivable results. ND filters appear grey and reduce the amount of light reaching the film, they have no affect on colour balance. They have 4 main uses:

i) To enable slow shutter speeds to be used, especially with fast films, to recored movement in subjects such as waterfalls, clouds, cars, seas etc.

ii) To decrease depth of field by allowing wider apertures to be used, which helps separate foreground from background.

iii) To decrease the effective ISO of high speed film (i.e. above ISO400) and allow it to be used outdoor in bright situations.

iv) To allow cine and video cameras (which have a fixed shutter speeds) to film subjects such as snow, sand or other bright scenes which would normally cause overexposure