Re: dreamy Nikon lenses
----- Original Message ----- From: "Mike Kirwan" <email@example.com>
Sent: Thursday, July 17, 2008 10:58 AM
Subject: RE: dreamy Nikon lenses
I remember a Pop Photo Article where Herb K waxed lyrical about theThe lenses used on the first Nikon rangefinder cameras were based on the Zeiss Sonnar and had a reputation for being very sharp beside being one of the fastest lenses available at the time (f/1.4). Many of these were remounted to fit the Leica M-2 and M-3 and this combination was very popular with photo-journalists at the time. All of these were coated lenses plus the Sonnar type is pretty low flare to begin with.
I think Argus used some Cooke Triplets. A Triplet can deliver very good quality but it is the simplest lens that can be corrected for all seven of the fundamental aberrations so there is not anything left to correct higher order aberrations. They are also very sensitive to element spacing. Triplets were made in speeds as fast as f/2.5 for 8mm motion picture cameras but are really not satisfactory beyond about f/4.5, maybe even slower. Most must be stopped down to f/8 or smaller to get the margins sharp. A Triplet is a low flare lens but if the spacing is off they can have quite a bit of spherical aberration. This is exactly the effect used in soft focus lenses and, in fact, some famous soft focus lenses, like the current Cooke lens, make use of this effect. Spherical looks like an overall haze but also results in a halo or glow around bright objects. It is different than the effect gotten by using a diffuser. There is always a core sharp image so the effect can very well be described as "dreamy". Some lenses, particularly the Goerz Dagor, have some uncorrected spherical when wide open and have a slight pleasant soft focus effect at large stops which goes away when the lens is stopped down because spherical is proportional to the stop.
Los Angeles, CA, USA