Re: dreamy Nikon lenses

[Richard Knoppow <dickburk@ix.netcom.com>]

----- Original Message ----- 
From: "Mike Kirwan" <mkirwan@pacbell.net>
To: <alt-photo-process-l@usask.ca>
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 the
> sharpness and detail obtained by those early Nikon lenses. 
> They became
> really popular during the Korean war. Many photo 
> journalists used these
> lenses on their Leica's.
>
> Now what you might be seeing is the result of some of the 
> local lenses of
> that time, like the lens that came with the Argus line of 
> cameras. They were
> not that high in resolution and they definitely had a 
> distinct look. Sort of
> sharp in the middle and soft at the edges.
>
> So my guess is an el-cheapo lens as opposed to a sharp 
> Nikon or leica lens.
> Unless of course the photographer shot the images with 
> some sort of
> diffusion.
>
> Mike
    The 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.

---
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com