Archived posting to the Leica Users Group, 1999/06/18
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]At 04:13 PM 6/18/99 EDT, DT wrote: >I remember someone telling me that the Hologon vignettes so much that a >graduated filter with a darker center fading to a clear outside is required >to even out the light falloff. If the edge falloff is 2 stops (f16) the >filter would need to bring the center to f16 as well. This is just hearsay, >but it makes sense except that I've used the 15 f5.6 and later f3.5 Nikkors >and they vignette some, but I never measured it at anywhere near 2 stops. >Can't imagine the Nikkors could be better than Zeiss ; ) This isn't "hearsay": it is in all the Zeiss literature on the Hologon and the Leica literature on the 8/15 Hologon. The Hologon outperforms any other extreme wide-angle lens in terms of linearity, sharpness, resolution, contrast, and so forth, but does vignette, and so Zeiss has always sold the lens with a graduated filter. Lens design is a series of trade-offs: if you want the absolute best in extreme wide-angle performance, the drawback is a slow lens. Marc msmall@roanoke.infi.net FAX: +540/343-7315 Cha robh bas fir gun ghras fir!