Herb, before I purchased the S convertor for my 300mm f4.5 FA, I spent some time with Pentax Colorado trying to determine the recommended usage. There was confusing literature out there and it took them a while to come up with the correct application info. IIR, it went something like the S is to be used on lenses shorter than 300mm except for the 300mm f 4.5, in other words not on the 300 f2.8 and 400, 500 & 600 mm lenses. Physically, I believe you could cause damage to the lens by trying to fit the L onto lenses where the S was recommended. The L has a significantly longer "snout" and would contact lens elements on those lenses.
Soooo you should get the L out of there. <GRIN> Kenneth Waller ----- Original Message ----- From: "Herb Chong" <[EMAIL PROTECTED]> Subject: Re: tele extenders > although the L fits the FA* 400 f5.6 and seems to work so long as you don't > focus too close. > > Herb... > ----- Original Message ----- > From: "Kenneth Waller" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Friday, March 26, 2004 7:35 PM > Subject: Re: tele extenders > > > > Its also not good to try to put the L convertor on the 300mm f4.5 FA! > >