July 16, 2011, 4:04 p.m.
posted by lordnikon
By far the easiest way to convert an image to grayscale is to change color modes. To do so, choose Image>Mode>Grayscale. With the Grayscale mode conversion, Photoshop throws away the color information in the image and converts the brightness of the pixels in the image to 256 levels of gray.
The resulting grayscale image is pretty good, but the finer areas can become a bit fuzzy and the overall cast can be a bit dark. Figure shows a lovely photograph of Arches National Park converted from RGB mode to grayscale.
Figure: Converting a color image to grayscale using color modes works pretty well, but the overall cast can be a bit dark.
When you convert an image with more than one layer to grayscale color mode, Photoshop asks whether you want to merge the layers. If you want to keep the layers separate, select Don’t Merge.