Planar best lens ?

I read recently that the best lens ever produced was the 1960 Zeiss Planar 50mm f2 as fitted to the Contarex. I thought this was a pretty bold statement to make but he was a lens designer although I don't know whether was a novice or an expert. However since I have such a lens in a Contarex ( not a nice camera to use) and also an f2 Planar in a Kyocera Contax, I did some tests. In B&W ( I did not do any colour tests) the earlier Planar was markedly sharper at 20x16. I would say also sharper than my Summicron in my Leica M.

Is there anyone who is a lens/glass expert who can say what lies behind the so called expert's statement. Is there some technical reason such as a rare glass that is too expensive to use in mass produced lenses ? Personally the differences don't matter at all to me but it was a provocative statement which is supported by my amateur tests.

The planar lenses are legendary, but whether this is based in fact or

urban myth is still open to question to my mind. The Contarex uses a

leaf shutter I believe, and so will give less vibration than the FP

shutter in either a Leica or a Yaschica. Like should always be

compared with like.<br>I have a Zeiss Biotar lens, supposedly the same

design as some planars, which is capable of astonishing resolution in

the centre of the field, but quickly falls off toward the

edges.<br>Personally, I don't think there was any magic ingredient in

lenses of this era, apart from TLC in their construction.<br>It was an

era which could combine the benefits of now vanished hand

craftsmanship, with post war advances in precision machinery and

computation. (Note the word 'could'). Planars in Hasselblads and

Rolleis of this period are also highly prized, although they're quite

different in design.

The Planar design is, as Pete says, legendary. The original design is

credited to Paul Rudolph at Carl Zeiss about a hundred years ago. At

that time, the only lens coatings were in Henry Taylor's lab, and so

the Planar was more or less unmakeable: with that many glass-air

surfaces it flared too much. So Dr Rudolph designed another lens,

based on Taylor's Cooke Triplet, with four elements in only three

groups -- the Tessar.

<p>

It must have been an exciting time in lens design!

<p>

With the advent of "bloomed" lenses in the late 1940s, the Planar

became a reality. And the handmade build quality of Leitz, Zeiss and

Rollei in the 1950s and 60s was quite remarkable. So your source's

opinion is not a frivolous one.

<p>

Of course, there is a slight element of "Is Beethoven a better

composer than Mozart?" in comparisons between the best lenses of that

era.

<p>

And there is also a problem.

<p>

Single coating was available in 1960, but not multi-coating. And

multi-coating revolutionizes contrast and colour rendition in lenses

-- it is probably the second biggest technical advance in photography

in the second half of this century. So I would be surprised if the

1960 Planar was not beaten -- even if only slightly -- by some modern

computer-designed lenses using modern glasses and coatings.

<p>

Later,

<p>

Owl

Quite some years ago I did some comparison series with the Planar and

f2.0 and f1,8 Nikkor standard lenses on slow B&W film shooting the

proverbial brick wall for resolution. I then checked the negs with a

loupe. Wide open and closed down one stop, the Nikon lenses won hands

down... to get comparable sharpness with the Planar required stopping

down to f4,0- f5,6. Now, this does evidently not cover other optical

properties like bokeh and color rendition (which I remember as

slightly warm). Still, it is a nice lens and the Contarex worked like

a charm though 35 years old.

<p>

Karl Johan

I don't want to derail this thread, but where the heck does this idea

of 'bokeh' come from. It seems to have sprung out of nowhere, like so

much other new-age drivel. Even the origin of the word isn't clear.

I've heard it claimed that it's of Japanese origin, but it seems to me

that it's simply a phonetic spelling of 'Bouquet'.<br>It's my

contention that the out-of-focus character of the image is purely

dictated by the shape, or number of blades, in the iris, and has

absolutely nothing to do with the design, glass, or country of origin

of the lens.

My old 1939 copy of 'Photography Its Principles & Practice' by C.B.

Neblette covers objectives quite well. There's a bunch of text on the

Planar and its history, but the last sentence is telling: "The

relative aperture of the Planar is f/3.5, but owing to the presence

of considerable coma the definition at this aperture is not critical

and stopping down is necessary for critically sharp definition. The

Planar is no longer made, having been replaced by the unsymmetrical

anastigmats which have approximately equal speed and superior

correction." Now, the later Planar may be different in the glasses

used or the exact design, since it's faster, thus the only meaningful

answer will probably come from testing it. Still fun to think about.

<p>

On bokeh, I'm still skeptical though most now think the degree of

correction for sphereical abberation is involved. I did at one time

collect a bunch of 50mm lenses of different vintage and design, all

fitting a Nikon body. I shot the same scene with each, said scene

having highlights on water and other things bokeh supposedly affects.

I was careful to compare only shots taken at the same aperture and

with the same focus point. My conclusion was that I couldn't see any

difference at all in the out of focus areas, or much of anything

else. I suspect the more variables you remove from the test, the more

bokeh might be a preference for certain focal lengths or apertures.

I've yet to see a properly conducted test that shows any significant

difference between two lenses of the same focal length, shot at the

same aperture, of the same scene, on the same type of film. I will of

course instantly change my mind when confronted with any real data

that says something different!

Regarding Bokeh, here is a link that compares two 35mm f2 lenses. It

does show the difference, even they are Pentax, though.

http://www.takinami.com/yoshihiko/photo/fa35/FAvsK.html

If you look up the term bokeh on altavista, you will find a number of

sites relevant to the topic. I seem to remember the articles in

Phototechnique dealt with the term in principle. At the time of my

lens comparisons, I only did tests for resolution only on

photographic film.

<p>

Hope this helps.

<p>

Karl Johan

OK. I've done a bit of research, and it appears that the word should

actually be 'Bo-ke', pronounced as in 'spoken', so why we westerners

put an 'H' on the end is anyone's guess.<br>This business about

spherical aberration doesn't really hold water, especially when

bad boke is attributed to 'over-corrected' spherical aberration. No

lens worthy of the name has first order over-corrected spherical

aberration. Any over correction would be in the Seidel 3rd order, or

5th order zonal corrections, which are of very low magnitude.<br>I

find it hard to believe that these tiny errors can make a visible

difference to an out of focus blob several millimetres across.

Furthermore, since these are zonal errors, it should be easy to test

the hypothesis by simply stopping the lens down and seeing if the

character of the boke changed significantly.<br>A more likely

explanation, to my mind, is whether the iris is positioned absolutely

correctly at the optical centre of the lens. This position is well

known to be critical to the geometrical rendering of the

lens.<p>Anyhow, for the last 150 years, both photography and

photographers have got on quite well without concerning themselves

over 'boke'. I doubt that any of the world's great photographers will

find themselves demoted because they used the wrong lens.<br>It also

seems strange that the Japanese should concern themselves with this

phenomenon, but not be able to control it in their lenses.

Well Pete, I went and looked at the site Derming suggested. It looks

like a reasonable comparison, and the difference is obvious. I still

have to wonder if we're looking at some off axis contrast and

resolution difference. I wonder if the effect would be the same on

center. The thought also occurs to me that one could make a Bokeh

test target, sort of like a USAF target only with various size white

circles. You'd shoot it out of focus, then evaluate the edges of the

circles. Take a look at the two photos and tell me what you think-

I've been curious about this for quite a while.

I did not realise how well repected the 1960s Planars were till I

read the replies and some e-mails sent to me directly. There seem to

be a great number of people who enjoy testing lenses against each

other. The sum of all the emails is that many seem to think that the

Planar of the Contarex was possibly the best lens ever made - no

doubt there were some not quite as good as the others - and that it

was made in an era before plastics and mass production. An

interesting email from Australia was from someone who had tested the

Contarex Planar against current Planars, old and current Nikon, Canon

and Pentax lenses. etc. He says that none of them come near to the

resolution and correction of the 1960s Planar so even Kyocera aren't

keeping up the brand. Thanks for all your interesting comments. (By

the way the Aussie now uses a Pentax 6x7.)

Hi Conrad, and sorry to fragment and hijack your thread this way

Anthony.<br>I've looked at the URL in question, and I agree that the

images are very different, but I'm not 100% convinced. The little clip

that's supposed to show the AF lens at f/2.8 actually looks more

blurred than the supposed f/2 clip. There's also a subtle shift in

viewpoint, and that doesn't help with a comparison.<br>As you say,

Conrad, it needs a proper test target and more controlled conditions

to really determine what the effect is. It may even come down to

something crazy like air bubble inclusions in the glass, or the

cleanliness of the lens.<br>I've recently aquired a very sophisticated

computer optical simulation program, which can generate spot diagrams

for through-focus conditions, and the change from 'doughnut' to

gaussian light patches can easily be seen as a lens passes from

positive to negative defocus. What parameters affect this, I've yet to

determine.