BW-Plus is a single Photoshop-compatible plug-in filter for quickly turning your colour images into greyscale, but with the added option of using a coloured optical lens filter as you would in traditional B&W photography. The different colours will change the tonal range during the greyscale conversion : for example, a red filter will lighten the red, magenta and yellow areas plus darken the green, blue and cyan in the photo. There are 6 preset effects to choose from using a simple drop-down menu