lens : The 58mm 1:2.4,
lens design taken from the Asahiflex. The
first standard lens lens for the Asahi-Pentax 1957 ,
"preset" type with dual aperture rings. The preset mechanism works fast
on these lenses and smooth like silk.
Comparing these pictures you can see that it's slightly longer than the other one with a thick (though not large) front element. 5 elements in 3 groups, you've got a classical Heliar type..! It speaks for Mr. Suzuki's - lens designer at Asahi Optical then - knowledge, or admiration for the German lens design that he took the famous pre-war Voigtlander large format portrait lens as a starting point to design Asahi Opticals first standard lens of higher speed for the "Asahiflex-II" in 1954.
There is no other Heliar type standard lens for 35mm still photo film that I know of, neither for SLR nor Rangefinder cameras, before 2001 Voigtlander/ Cosina made a remake with lower speed (f/3.5)
No cocking, no aperture pin, no automatic diaphragm on these early lenses! focussing scale either "meter" or "feet" according to market, never both. Be careful with these screw-mounts (alloy thread!)
|Hot, very hot... In 1957
it was not so clear in Optical business which standard lens design will
win the battle - the only one Gaussian type in this bunch
the 55/2.2, and the least expensive one to build. It had one
element less than all later well known
versions: 5 single elements - quite uncommon an idea in the 1950's
years, if not to say curageous.
This type was kept as the "cheaper" choice in production for 1958 (Pentax "S") in 1958, with dual scale (feet and meters) and higher S/Ns.
I found this one (with feet-scale) on a 1959 Pentax H2 - automatic diaphragm never worked with this preset lens in 46 years... I estimate contrast isn't up to later standards, due to its simpler construction. Don't confuse with the later Auto-Takumar 2.2/55mm which have the modernized 6-elements design!
|Fastest and rarest standard lens for the Original Pentax:
Takumar 58mm 1:2.0
Unlike all later types which are Gaussian without exceptions - until present! - a Sonnar type (6 elements/ 4 groups, the second group beeing a cemented triplet). This was also the first Pentax lens with an Infrared marker.
From this perspective, you can clearly see this lens has bigger and more protuding "glass" than the 55mm/2.2 at a very comparable speed , thus probably leading Mr. Suzuki rightfully to the adoption that the Gaussian design was the best point to start with developing faster apertures like f/1.8 and later, f/1.4
Pictures taken with this lens
|The last preset lens, replacing the
expensive to manufacture 58/2.0 was a Gaussian 6 elements/ 5 groups
(Ultron type) was probably developed towards the end of 1957.
This is the rarest of the preset lenses, sold in small numbers with the Pentax S (the last remaining preset SLR in 1958). It was also the fastest SLR lens of the world in the 50/55mm range back than! (with just the 75/1.5 Carl Zeiss Jena Biotar beeing faster)
This lens starts a long series of famous Gaussian design standard lenses of this speed and focal length becoming Pentax standard for the next 40 years.
S/N's from this lenses are prior to the "zebra style" Auto Takumar shown in the next table.
|For the Pentax
K with auto-diaphragm-mechanism innert the mount there was a
need for a new set of lenses to support this feature (also
1957 preset series can be used).
The first approach was a semi-automatic diaphragm which needs to be cocked by a lever 90 degrees for each exposure to full aperture (see cocking lever under the "Feet" scale) and was released by the camera when triggered just before shutter fires.
Top-of-the-line lens in 1958 was the Auto-Takumar 55/1.8, with fasciated focussing ring, having dual scale "meters" and "feet". Available only with the Pentax K. Known as the "zebra style lens" (only Pentax lens with this outline).
This was also the first of the famous Gaussian design (6 elements in 5 groups) becoming Pentax standard until the next 40 years for the 50-55mm focal length of that speed.
1959 there were 3 "standard" types - now all Gaussian
designs: with 6 elements in 5 groups:
Most of them were later changed to "Super-Takumar" type lenses which worked nicely with the older cameras without need to be cocked. But these later series add size and weight too!
There is no difference in glass or performance (except the last S.M.C. types multicoating). So please keep and beware them
|A lens of the 1970's? Wrong!
This Auto-Takumar 1.8/55mm was the top-of-the-line lens for the Pentax S3 (1961). Despite of beeing labeled "Auto-Takumar" it was in fact the first full automatic diaphragm lens (no cocking lever longer needed, Auto/Manual switch) - exactly that what Pentax later on called Super-Takumar.
This was, also, the first Pentax standard lens which had the "focussing scale window" (later becoming a typical Pentax characteristic) and the aperture ring next to the camera body. Note that this one runs counter-clockwise! It is also the first standrad lens with an 49mm filter which became standard with Pentax. Older lenses have a smaller 46mm filter.
the world first Retrofocus- wideangle lenses - and in 1958 the
fastest SLR 35mm
lens with f/2.3. An argument for press-photographers to buy PENTAX in
these years.... Build until 1962, then replaced by an f/2.0 with even
size. But it's build sleek (weight 306g,
Probably the first and soley 65mm Filter mount Pentax lens. Chrome lens cap included. A sun shade for this monster? Who knows...