Last year, Canon posted an interesting video showing the manufacturing process behind the EF 500mm f/4L IS USM lens that costs about $5,800. Now a photographer has posted his own site that that illustrates why the comparatively lowly EF-S 17-85MM f4-5.6 IS USM costs about $500.
A FredMiranda forum member named Sam posted some photographic details of his lens disassembly after his model suffered a stuck aperture, the mechanism that regulates how much light goes into the lens. Fittingly, the last photo he took was of an exhibit at a Parisian Arab-Islamic museum that features dozens of apertures.
As you might imagine, the lens is an amazing feat of electromechanical miniaturization. I found the most intriguing shots to be of the slotted mechanism that converts rotation of the focusing and zoom rings on the outside of the lens into movement of component assemblies on the inside. Also, the copper windings of the motors controlling the image stabilization are fascinating. I was a little surprised how small the broken aperture actually is. In all, there are dozens of components.
Having stripped some screws and not kept track of the disassembly order, he decided against trying to reassemble it. "Overall, the inner workings were a bit more complex than I expected, but it was a nice linear process taking it apart," he said.
So at the end of it all, he turned the lens into a pencil holder.
Bonus link: Also, if you're in a more constructive frame of mind, the Japanese camera giant also shares instructions on how to make a Canon SLR out of balsa wood.