Archived posting to the Leica Users Group, 1999/09/11
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]The October Popular Photography includes a test of the Cosina/Voigtlander 15 mm f/4.5 Heliar. While I realize Pop Photo's tests aren't universally respected (though Erwin has posted that he finds their testing methods among the better ones), I've yet to read dispute with their actual tested measurements. And they test the resolution of the Heliar, at f/4.5 and f/5.6, to be 96 lines/mm center and 57 lines/mm corners. They write, "....lines-per-millimeter resolution test produced the best results we have ever seen for an ultrawide-angle lens, with central sharpness at f/4.5 and f/5.6 even exceeding that of the fabled 16 mm f/8 Zeiss Hologon at its only aperture. (Our test Hologon yielded 90 l/mm centrally and 70 l/mm in the corners.) Minimal pincushion distortion (0.45 percent) was about twice that of the Hologon's barrel distortion (0.23 percent), but still considered quite small." Interestingly, they also measure the Heliar's aperture to be f/4.12, making it closer to an f/4 that an f/4.5 lens. So it would seem the Heliar resolves a little better than the Hologon in the center, the Hologon a bit better in the corners, though both are excellent. But the Heliar being two stops faster will make it far more useful to me in the field. (By the way, Leica has a full page full color ad in this issue. I can't remember the last time I saw that in Pop Photo.) Larry