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Hoya 77mm ND4 HMC Filter
Product Description :
To enable slow shutter speeds to be used to record movement in subjects such as waterfalls clouds cars etc
To decrease depth of field by allowing wider apertures to be used which helps separate subjects from their background
To decrease the effective ISO of high speed film ie above ISO400 and allow it to be used outdoors in bright situations
To allow video cameras which have fixed shutter speeds to film subjects such as snow sand or other bright scenes which would normally cause overexposure