Reinventing the Tessar Lens

"And maybe lens designers come up with designs that use many more than 4 elements, including aspherics and exotic glasses, just for the fun of it?"

 

There were other factors. Complex lens designs were well known already in the 1910s.

 

Before coated optics became available, lenses with many elements were subject to significant light loss in the air-glass interfaces. More groups, more air-glass interfaces. Each air-glass surface implied light losses or the chance of increased flare; this effect increased quickly after about 3 elements. Uncoated lenses with many elements, such as the pre-war Sonnar, give lower contrast than a contemporary Tessar-type..

 

After coating became available, mostly post-1945, complex designs flourished (such as the Sonnar, Biotar, and so on).

Julio, a number of makers produced lenses with as many as ten elements and low flare before WW II. Several of the designs persisted into the early 1980s and one was revived later.

 

The trick is that the lenses were all more-or-less symmetrical double anastigmats with many cemented elements in two groups. Goerz Dagor and similar. The last to die was Boyer's Beryl. The ghost that came back was Schneider's Fine Art XXL lenses.

I just found a post that says the Tessar patents were long expired when Leitz designed the Elmar.

So maybe Leitz just wanted something different. I dunno.

 

Edit: Oh, and Mr Elwing's post, above.

 

 

Edited March 20, 2018 by scott_paris|4

Ohhhh, creamy BOKAH!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

Nice idea, hope that he does well with it and the resurrected lens company name. Say, does anyone else feel the principal in this looks like he escaped central casting--for the roll of WWI villain?

Coating reduces air/glass reflection by 4%-9% depending on glass refractive index, most on the lower side.

The Dagor was 6 elements cemented into two groups, as were a few Berthiot lenses, so only 4 glass/air surfaces, but all slow around f6-f7 So was the Beryl. They would have lost little light in transmission. I can't find any with more elements. A fair number of Petzval cine lenses were also in two groups.

The Sonnars f2 & 1.5 were in three groups = 6 glass/air surfaces while the Leitz Xenon f1.5 had 5 groups,= 10 and the Summar f2 had 4 groups = 8 air surfaces, so whatever other qualities there were, the Sonnars were more punchy, more like coated lenses before coating turned up at the end of the 1930's.

My understanding is that slow-ish lenses like Tessars and Elmars, also with 6 glass/air surfaces, with reflections around 4%. That's why, uncoated, they still behave quite well with film.

Sorry, just got a bit carried away......

@scott reference to the Elmar... nice write-up from Rockwell

 

LEICA ELMAR 50mm f/3.5 Review

Ohhhh, creamy BOKAH!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

Nice idea, hope that he does well with it and the resurrected lens company name. Say, does anyone else feel the principal in this looks like he escaped central casting--for the roll of WWI villain?

I thought he bore a distinct resemblance to Lex Luthor.

"Coating reduces air/glass reflection by 4%-9% depending on glass refractive index, most on the lower side."

 

That is the point. With 10 surfaces and 5% you get 63% loss. It adds up.

I understand its not total % loss, but lots of light bouncing around inside killing off contrast.

I take my Carl Zeiss Tessar everywhere. Bratislava last week:

camera and coffee by Ken, on Flickr

I take my Carl Zeiss Tessar everywhere. Bratislava last week:

camera and coffee by Ken, on Flickr

So, if you're photographing your Zeiss, with what lens/camera are you photographing it?

So, if you're photographing your Zeiss, with what lens/camera are you photographing it?

In this case my D600

It's a good model, stays still :)

I have a prewar Rolleicord that I think has a Zeiss Tessar on it, although for all I recall it might be a Triotar. I haven't used the camera in years-it unfortunately got sidelined. Even though I'm not fond of Rolleicords in general, if I use one I use my Va because it has a lot more creature comforts and a better lens(coated Xenotar).

 

I've had earlyish Rolleiflex Automats with CZ Tessars on them, but ultimately kept the Xenotars because at worst they were the same and at best would often outperform the Tessars.

 

The only Zeiss lenses I have now are for my Hasselblad, and of course those are more complex designs(Distagon for the 50mm, Planar for the 80mm, and Sonnar for the 150 and 250mm). I have a bunch of Tessar type lenses, but none with the C-Z name on them.

 

BTW, most of my large format lenses(with the exception of the monster 75mm Nikkor-SW I picked up not too long ago) are Tessar type lenses. They are all relatively slow(I think f/4.5 or slower) but are absolutely outstanding when stopped down. That's one area where I think the Tessar design really comes into its own. The only issue is that most of mine-especially the Kodak and Wollestock ones that were often of Graphic cameras-have fairly "tight" image circles.

 

Both the Nikon Tessar-type lenses are excellent(there again-if you stop down to get rid of some vignetting and corner softness) and a lot less than this lens.