If you have a SLR or DSLR camera and other maker/mount lenses, the PBL Mount Adapters allow you to use your lenses on the film/digital camera body. Sharing lenses has some distinct advantages. Certain prime lens just can't be replaced, and you save cost of purchase lenses. PBL offers a range of adapter from large format to smaller format digital adapters. Adapting larger format lens, i.e., large format - medium format, medium format - 35mm, excellent edge-to-edge sharpness and the smaller 24x36 mm image field helps minimize the effects of lens distortion and aberration.