Willie Chik, The Computer Programmer who is also a photographer made a web application that can help us to find a perfect lens  that suitable with our own taste. How? He displays dozens sample photos and we can choose 20 photos that we like. From 20 photos that you will choose, application algorithm will find which the best lens for you.

BUT! Because WhatTheLens Application has been made a few weeks ago, the lens database is still limited. So far he just support the mount of the lens for Canon (EF) and Nikon (F). But actually it's not problem, we can just adjust the lens type that recommended by application for akin which is suitable with our camera mount.

I tried choose 20 photos of people (NSFW) on the display, and the application choose Canon EF 70-200 mm f/2 IS USM. The perfect recommendation for me. If i think it too expensive, i will just to find the other lens which is similar which is lower price . Need to remember! The focal length that we use us for full frame censor, so when you use Crop Camera, of course you must pay attention with crop factor. 

You can try open the website WhatTheLens Web Application.