ValueViewer is an indespensible tool for artists who paint from life. Whether "en plein air" or in the studio, ValueViewer will allow the user to take a photo of their subject, view it in grayscale, or posterize it into two or three values. You may also select an existing image directly from a photo album on your iPhone or iPad. Controls let you adjust the light, mid-tone, and dark area of your image to "key" your painting correctly, and assist in helping you "see" value, even in the most unforgiving light. The image can be zoomed in and out, scrolled, and rotated into position to help you find just the right composition for your painting. Convenient adjustable 'frame' overlays help you crop the image to fit your canvas, and grids can be displayed to help you transfer the image to your canvas.