you could desaturate your image or convert it to black&white and then use (image>adjustments>)posterize, with a value of 2 for levels... or use (image>adjustments>)threshold for more precision... but if you want to have a halftone pattern you have to convert your image to black&white (desaturate doesn't work in this case...) and then go to filter>pixelate>color halftone and click ok... then you could have grey things like shadows, but still the image is purely black and white... i hope this helps... grd