Prompted by the inhumane conversion of a Pentax K 15/3.5 to a Nikon mount (in the "Poor SMC Pentax 15/3.5 in a (Gasp!) Nikon Mount" thread), and wondering just how the Pentax 15/3.5 design stands up to the apparently more expensive Nikon 15/3.5, I dug out some Amateur Photographer reviews. (The bottom line is that AP found the two lenses to be very similar.) The K and A 15/3.5 lenses have been reviewed in Amateur Photography at least three times:
"Test Report - Ultrawide from 7.5 to 24 mm", March 13, 1982 (K 15/3.5, along with Hoya 24/2.8, Canon 20/2.8, Tamron 17/3.5, and Minolta 7.5/4). "All -Round Vision", Dec. 15, 1990 (A 15/3.5, along with Canon 15/2.8, Sigma 15/2.8, and Nikon 15/3.5). "Superwide Shoot-Out!", March 12, 1994 (A 15/3.5, along with Canon 20/2,8, Minolta 20/2.8, Leica 19/2.8, Tokina 17/3,5, Vivitar 19/3.8, Tamron 17/3.5, and Sigma 18/3.5). >From 1982: "This lens looks like something used on a moon mission." "Despite its size, the Pentax handles very well. Focusing was a little stiff and the viewfinder image a little dark, despite the quite large f/3.5 maximum aperture. Distortion is remarkably low for such a wideangle. If kept horizontal, it is difficult to believe you are looking through a 15mm lens because of the lack of distortion." "There seems little point in including both skylight and UV filters as they are much the same - a red or correction filter would have been more useful." "The focusing movement is very short because of the massive depth of field." "Performance of the Pentax was very good. Test prints were slightly soft at full aperture but crisp from f/5.6 right down to the minimum aperture. Contrast held up well." Overall performance - Very good Central definition - Very good Edge definition - Very good Image contrast - Very good Optical balance - Good Best central definition - f/11 Best overall definition - f/11 Best edge definition - f/11 >From 1990: "The Pentax lens is free from barrel distortion and is good value for money." "This Pentax and the Nikon [15/3.5] both show less rectilinear distortion than most zoom lenses. At the edges of their respective fields the deviation from the straight in the images is too small to be reported." "In both lenses, it was possible to measure the resolving powers in the outer field, and it can be said that the images held up their quality to a previously unheard of degree." Measured focal length - 15.8mm [Nikon was 15.7mm] Distortion - Rectilinearly corrected [same for Nikon] Central definition - Excellent [same for Nikon] Edge definition - Excellent [same for Nikon] Overall - Excellent [same for Nikon] [Resolution graphs also shown] [Best high contrast resolution in center at f/8 and f/11] [Best high contrast resolution in edge at f/8] [Best low contrast resolution in center at f/8] [Best low contrast resolution in edge at f/16] >From 1994: "In looking at the test graphs, keep in mind that this is a 15mm lens which has very good overall performance and note there's somewhat more barreling than is to be found in the previous three objectives [the Pentax was the widest lens tested in this review], and one stop drop in corner illumination at open aperture is to be regarded as something of a miracle in a 15mm low-distortion lens." Color shift - Neutral Distortion - Slight Vignetting - Very slight Low contrast image quality - Very good High contrast image quality - Very good Overall - Very good [Resolution graphs also shown] [Best high contrast resolution in center at f/11] [Best high contrast resolution in edge at f/11] [Best low contrast resolution in center at f/11] [Best low contrast resolution in edge at f/8] [end] Fred - 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 .
