>andre wrote: >If this is the case, Bruce, Vivitar's marketing strategy is >surprising: write 19mm on a lens that could be called 18mm or 17mm ! > >Andre, > >This could have been part of the marketing agreement with Tokina. > >In the same way, perhaps, Kino Optical had to call its Kiron 105mm >macro an f/2.8, while Vivitar got to call it an f/2.5, even though >Kino was the manufacturer. When Vivitar decided to broaden the >market by selling the lens at a lower price point (without the >Series One badge), the big V called it a 100/2.8. They probably >hoped this would keep the lens from cutting into the Series One's >market share.
That makes sense, Paul. If I remember, Modern & Popular Photography were (and still are, I guess) accepting a 5% "play" on focal lenghts. So the real number is probably 18mm. (Even then, it would go a bit over a 5% difference at 17mm and 19mm.) But Pop Photog is just suggesting a limit. Anyone with the real focal lenght from a test ? I might have it but in a box somewhere... By the way, I found an excel file with the real Pentax focal lenghts. I'll reformat it and post it soon. Not only Zeiss made a 25mm lens... Andre > >There's an excellent discussion about these cross-marketing >arrangements at http://people.smu.edu/rmonagha/third/index.html > [EMAIL PROTECTED] -- - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
