Originally Posted by frank 
Some big front elements:
Lens porn, my favourite!
So how about something
dirty?
My battered CZJ Flektogon 35/2.4. The optics are great, but the outside is somewhat scratched.
Getting in a bit closer:
Taken with smc Pentax-M 50/4 Macro + 36mm and 68mm tubes and AF280T.
Richard