I take no issue with your observations, however I'd never try that with any lens that I own, it seems like you're asking for trouble. Kenneth Waller ----- Original Message ----- From: "Herb Chong" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Friday, March 26, 2004 8:17 PM Subject: Re: tele extenders
> well, i know about the greater than and less than 300mm specification for > the L and S extenders. i focused the entire range on the 400 f5.6 by hand > without a camera attached to see the range of travel. it looks like i can > focus to about 15 feet or so before the rear element would hit the L > converter. in MF mode, the focus clutch slips as soon as it encounters > resistance. the lens end of the L converter is covered with rubber where the > retaining ring/cylinder holding the rear element of the lens would contact. > from what i can see, i would not damage anything in MF mode hitting the rear > element cylinder against the rubber ring, but it would be inelegant. i have > to use an S converter on my FA* 80-200 f2.8 because the rear element is > fixed and right up against the lens mount. > > Herb... > ----- Original Message ----- > From: "Kenneth Waller" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Friday, March 26, 2004 7:56 PM > Subject: Re: tele extenders > > > > 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. > >
