Takumar Hair Splitting

[Michel Hardy-Vallée]

Next in my series of "why is the world like that" questions concerns the screwmount Takumar lenses.

By the time the lenses were at the Super / Super-MC stage, I am trying to figure out why Pentax would produce a pair of lenses like the f1.4 50mm and the f1.8 55mm. In terms of aperture, the difference is negligible, and likewise in terms of focal length. I wouldn't see a reason for someone to own both. I am sure most people chose either of these.

Ditto for the 35mm Takumar: they exist in a f3.5 and an f2 version.

But why did Pentax produce such apparently nearly identical lenses, and above that sell them at different prices? The one thing I know is that the f1.4 50mm and the f2 35mm had thorium which cause them (like my 50mm f1.4) to yellow slightly after age.

 

[Donald Qualls]

The half stop faster lens was a big deal when f/1.4 was the fastest SLR lens you could buy. Conversely, the 55 f/1.8 was significantly cheaper than the faster lens, but could use the same filters (because the slightly longer, slightly slower lens had the same barrel diameter).

A couple years later, you could collect a $100 premium for f/1.2 vs. f/1.4 (which was real money in 1970).

 

[Marco Gilardetti]

The lens lineup (optical design) and optical optimization is usually different among these cases. f:1,4 "normal" lenses are designed for best performance at wider apertures, where usually the f:1,8 gets "weak". But on the other side, the cheaper f:1,8 usually beats the more expensive f:1,4 in sharpness with diaphragm fully closed.

You see, as in most cases, one's strong point is the other one's weak.

 

[Mark Layne]

I recently took a 35 f2 and a 35 f3.5 on a trip.
The f2 with its built in radioactive yellow filter is superb even in backlight. The f3.5 was multicoated and even at f8 is dreadful in the corners.
There are two versions of the f2 -one uses a 58mm filter. There also exists a 35 f2.3 which I really haven't tested much. It seems ok.
Mark

 

[Steve Roberts]

Hi All,

Somewhere recently (it may have been in Keppler's "The Pentax Way") I read that with the Spotmatic etc. viewfinder optics the 55mm lens gave a true life size view of the subject (not sure why that matters) whereas the 50mm only gave 0.9X life size. The way I read it was that buyers were invited to choose between life size or half a stop faster.

I have several of both focal lengths but rarely use the 55mm as I find that for the kind of things I'm photographing the difference in viewing angle, albeit small, is often significant. (In case anyone asks why I'd have lenses I don't use, I'm also a collector and they turn up attached to bodies!)

Slightly off-topic, I was always amused by the adverts for the then "new" SMC lenses which showed two supposedly identical shots into the sun, one without an SMC lens and one with. The reduction in flare was staggering - until you looked closely and realised that the scantily-clad yound lady had moved over for the SMC shot, obscuring more of the sun than in the other shot!

Best wishes,

Steve

 

[df cardwell]

....snip....the 55mm lens gave a true life size view of the subject (not sure why that matters) .... snip....
Steve

Shooting with both eyes open, with a 'life size image', is a rare pleasure. Like eating a ripe tomato, it has generally become a memory of another age.

.

 

[titrisol]

The 1/2 stop made a lot of difference back then.
IMHO the 55/1.8 is a sharper lens than the 50/1.4, even fully opened

 

[Gerald Koch]

The 1.4 is useful in limiting DOF. Which is why it is optimised for large apertures.

 

[Dan Fromm]

Next in my series of "why is the world like that" questions concerns the screwmount Takumar lenses.

By the time the lenses were at the Super / Super-MC stage, I am trying to figure out why Pentax would produce a pair of lenses like the f1.4 50mm and the f1.8 55mm. In terms of aperture, the difference is negligible, and likewise in terms of focal length. I wouldn't see a reason for someone to own both. I am sure most people chose either of these.

Ditto for the 35mm Takumar: they exist in a f3.5 and an f2 version.

But why did Pentax produce such apparently nearly identical lenses, and above that sell them at different prices? The one thing I know is that the f1.4 50mm and the f2 35mm had thorium which cause them (like my 50mm f1.4) to yellow slightly after age.

Not to point out the obvious or anything like that, but if you dismantle the two lenses you'll find that they're not quite the same. The 50/1.4 contains more glass and is a more complex design. It cost more to make that the 55/1.8. Going from f/1.8 to f/1.4 is not a tiny step.

The 55/1.8 is an older design, dates from the days when "normal" lenses for 35 mm SLRs weren't at all retrofocus and had to be longer than the conventionally accepted normal focal length for the format (50 mm) to clear the mirror.

As to why people were willing to pay a premium for 50 mm and f/1.4 over 55 mm and f/1.8, I'm not sure. When I bought my first Nikon in 1970, I chose the 50/1.4 rather than the 50/2.0 because I thought I'd need the speed. I mean, it was often pretty dark where I then lived, even at noon. And I used the speed; I have a couple of barely acceptable shots taken a little after sunset that would have been impossible with the slower lens. But after I got a 55/3.5 and realized the absurdity of carrying two lenses of about the same focal length, I learned that a fast lens wasn't the only way of coping with, um, darkness and got rid of the 50/1.4.

The short answer to your question is, "Because."

 

[Michel Hardy-Vallée]

Thanks all for your great responses, it does make much more sense now. Together, they make the picture complete: manufacturing, design, optimization.

As a comparison, I looked at the current Nikon lens lineup and they still sell both an f1.4 50mm and an f1.8 one. The f1.4 closes until f16, while the f1.8 can close to f22. Pentax also sell an f2.0 - f1.4 pair of 50mm primes, although both can close to f22. The desing also is different between the two (5g5e for 2.0; 6g7e for 1.4).

So I guess even 30 years later, those differences matter to some people!

 

[RonJ]

I bought my first Spotmatic in 1968. I was 20 years old. The main reason I bought the f1.4 Takumar was because the relatively huge chunk of glass looked impressive on the camera. When I look at my Kodachromes from those days I'm still impressed by the sharpness.

RonJ

 

[mawz]

That 2/3rds of a stop (1/2 stop is f1.7 to f1.4) can be a big deal for dedicated low-light shooters. The 1.5 stops between f2 and f3.5 on the 35 is even bigger (getting you from sconsumer zoom speeds to a fast prime). The shallower D0F allowed by the faster lenses is also a major reason.

I shoot a lot of low-light high ISO stuff, and keeping the shutter speed at 1/30 is a big deal when shooting with the 50's or 35's. Last night I was shooting in a bar, with 3200TMZ. I had my 35/2.5 E and 55/3.5 Micro with me and was missing my 50/1.8 E badly, the extra stop over the 35 and almost 2 stops over the 55 are a big deal in low light, I eventually had to pull out the flash because I had enough light to shoot a 1.8 acceptably (A 1.4 or 1.2 would have got me into 'no problem' territory) but the slower primes were only netting me 1/15 or slower, which simply is too low for acceptable shooting.

 

[stark raving]

Conversely, the 55 f/1.8 was significantly cheaper than the faster lens.

Indeed. I bought a Spotmatic with 55/1.8 in 1970. I couldn't afford the 50/1.4, I believe it was $60-80 more expensive. That was a big chunk of change to a 14 year old in 1970.

 

[luvcameras]

This page may help

http://members.aol.com/dcolucci/takumar.htm

Dan