----- Original Message ----- From: "Arnold Stark" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Sunday, April 06, 2003 1:25 PM Subject: Re: M-20/4 vs. K-24/2.8 ?
> whickersworld schrieb: > The 24mm f/2.8 Nikkors are effectively > distortion-free. > > " effectively distortion free" is a nice expression effectively meaning > either "distortion is still greater than 0" or "the distortion did not > spoil any of my pictures". In these senses, the A20/f2.8 as well as the > K24/f2.8 could be called distortion-free, too. However, the M20/f4 is > not " effectively distortion free" as for me it did indeed produce some > ugly distortion with the horizon near the upper image border. > > However, if one systematically MEASURES distortion (i.e. the bending of > straight lines), there is no super-wide angle lens that I know of that > really is distortion-free. > For example, in 2001 German Color Foto tested 15 lenses of all major > brands (including FA24/f2, FA20/f2.8, ands also the Nikkor 24/f2.8) with > focal length between 19 and 24mm. No lens collected more than 5 points > out of 10 for its distortion performance (with Leica and Zeiss > performing best). > Here is some test results on Pentax lenses from Chasseur d'images: > FA20/f2.8: 0.5% barrel distortion; FA24/f2: 0.4% barrel distortion; > A24/f2.8: 0.5% barrel distortion. Hi Arnold, That's very useful. Thanks. John
