How do I make a camera lens?

I am making my 16yrs old (as of Yesterday) a surprise birthday cake..he is an amazing photographer (even got TOP photographer of his school as a sophomore) so I thought I would make his cake an amazing camera cake!! YIKES!!!! I am even going to venture to MMF!

SO TIPS? Ideas? and how do I make a "clear" lens

gelatine... not entirely sure how youd go about it, but make it up, let it set, and cut out the circle.
piping gel maybe, just apply it to where the lens is on the cake.
although looking at google, most people just do black or white/ grey fondant, which i guess would be the more conventient option too!
xx

Gelatin sheet cut with a round cutter.

Isomalt set up a little then cut with cutter before hardening.

I'm not really sure, just a thought.

I might try to make the lens with a cupcake - perfect for the size...
The lens.. I've never used gelatin... but you could make it with the cap on the lens.. so it would be black, or leave the cap off and make it grey...

http://www.kakebakery.com/images/Camera_Lens_Cake.jpg

http://www.charmcitycakes.com/images/gallery/fun_14.jpg

Isomalt would be the way to go. I would pour it into a mold or at least use a round cookie cutter to keep it round. Just make sure you heat it well enough so it won't bubble. And if you don't want to go to that trouble, then the gelatin sheet will work well. Good luck!

I did a camera cake. You can cheat like I did and leave the cap on so you don't have to worry about the lens. The details didn't show up well since it was black fondant, but you can see it here...
http://www.cakecentral.com/cake-photo_1741849.html