Hi David The 21 SA and the 28 [1st version] have those li'l lip thingies on'em too. GaryP ----- Original Message ----- From: David Young<mailto:dsy@xxxxxxxxxxxxxxx> To: leicareflex@xxxxxxxxxxxxx<mailto:leicareflex@xxxxxxxxxxxxx> Sent: Friday, March 14, 2008 7:39 PM Subject: [LRflex] Re: Summicron lens on Oly problem... Aram proffered: Lets see: 35-70 f-4 has a ring that sticks out past the mount that is about 32mm in diameter 100 2.8 has nothing past the mount. 35 2.8 Has a substantial lip. Hard to measure but about 32mm in diameter 24 2.8 has two rings, one that sticks up about 1mm from mount and is fixed (does not move when focused) of about 35mm diameter, and one that moves when focusing of about 26mm in diameter 180 f-4 is no problem. 90 2.8 is no problem. And as you said, the 50 2.0 has that lip of about 35mm diameter. That's my collection. Didn't realize I have so many lenses. Thanks Aram! --- David Young, Logan Lake, CANADA Limited Edition Prints at: www.furnfeather.net<http://www.furnfeather.net/> Personal Web-site at: www.main.furnfeather.net<http://www.main.furnfeather.net/> Stock Photography at: http://tinyurl.com/2amll4<http://tinyurl.com/2amll4>