Officially the 1,7 converter will not focus with anything slower than 2,8 (source: Norwegian Pentax distributor, Fovi). But it does focus with my Vivitar S1 lens, and this is 4 at the long end. I believe the truth is that f:4 is the limit if the lens "contrasty".
So if I where you Toine, I would try it on a fast T glass before modifying the lens. Tim Mostly harmless (just plain Norwegian) Never underestimate the power of stupidity in large crowds (Very freely after Arthur C. Clarke, or some other clever guy) > -----Original Message----- > From: Jens Bladt [mailto:[EMAIL PROTECTED] > Sent: 6. april 2006 20:46 > To: [email protected] > Subject: RE: 1.7x AF > > Mine won't focus with a Tamron Adaptall 6.9 200-500mm !! > I guess it's never sharp enough?? Or is there any other explanation? > IOther than that I'm very impressed with this converter. I's actually a > brilliant piece of equipment. > Regards > Jens > > Jens Bladt > http://www.jensbladt.dk > > -----Oprindelig meddelelse----- > Fra: Toine [mailto:[EMAIL PROTECTED] > Sendt: 6. april 2006 20:24 > Til: [email protected] > Emne: 1.7x AF > > > I noticed my 1.7x AF converter doesn't autofocus with T-mount lenses. > It does autofocus with M-series lenses. The only difference I can > imagine is the K-mount on a M-series lens is electrical conductive and > the T-mount is made of (isolating) anodized Aluminium. > I feel temped to use fine abrasive paper to remove the anodized layer > on an old T-mount or short circuit two or more contact on the K mount. > Would that make any difference? Maybe dangerous for the D body? > > Toine > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.1.385 / Virus Database: 268.3.5/303 - Release Date: 04/06/2006 > > -- > No virus found in this outgoing message. > Checked by AVG Free Edition. > Version: 7.1.385 / Virus Database: 268.3.5/303 - Release Date: 04/06/2006 >
