# Why don't I see infinite images with parallel mirrors? [duplicate]

Sitting on the barbershop, watching myself in the mirror which is parallel to another mirror (so that two mirrors are parallel to each other), I was seeing an infinite number of photocopies. After a moment, I guess that it's really not infinite, I can count the number of copies.

But we know from our elementary optics course, that the two parallel makes an infinite number of copies. This leads me to ask,

Why it is that parallel mirrors not make infinite images?

Here I think the finite speed of light would play a role, but I think not that significant. I don't if it's due to the fact if the mirror is not that enough parallel or they are not enough flat.

• @Steeven That sounds like an answer! :) Should be relatively simple to figure out how "far away" the image in the mirror effectively is, and compare it to what you could imagine seeing. (EDIT: Whoops, you beat me to it! :) ) – Philip Mar 19 at 15:29
• @Philip You are right, I made it into an answer. Yes, agreed, if you measure the down-scaling for a few of the first reflections, I guess you can calculate how many reflections it'll take before the reflected image is smaller than what is observable with the eyes' photoreceptors. – Steeven Mar 19 at 15:39