1. A stamp collector uses a converging lens with focal length 32 cm to view a stamp 17 cm in front of the lens. Where is the image located? a. in front of the lens (real image) b. behind the lens (virtual image) 2. 1/f = 1/do + 1/di 3. 1/32 = 1/17 + 1/di di = -32.267 cm Because it's negative it is a virtual image. For this problem, I imagined front behind ---f--do---lens----------- A virtual image is in the same side as the object. So something like this: http://www.pa.msu.edu/courses/2000fall/PHY232/lectures/lenses/virtual_image.gif So then why does the answer say if its virtual it is behind the lens? Also, what is considered front/behind for lens/mirrors?