Lens evolution over the past 20 years

[Nikos]

I recently bought a mint Contax 2,8/135 on eBay.

I did not really need this lens, as I am quite covered in this focal length (see my signature).
However, I like Contax lenses and $200 was a good price.

Now I wonder, how has lens design evolved over the past 20 years?
In a Contax brochure of the 80's, Zeiss mentioned computer-aided lens computations etc.

We have much better computers now.

Putting quality control issues aside, do you think the top of the line Canon/Nikon of today can compete with the older Zeiss/Leica lenses?

Or, how do the new ZE/ZF lenses stack against their Contax counterparts?

Is it possible that my 70-200 f/2.8 IS II is actually optically superior to the Zeiss prime I added to my collection?

This is not a trivial question. Perhaps it is even subjective.
However, there are members in this forum who could offer opinions that are more than a guess.

[Orio]

Computers were used for lens computations as early as the 60s as far as I am aware.
For instance I am sure that Erhard Glatzel used computers for computations of the Contarex line of lenses and that was in the 60s.
Of course they were not the same computers as today

The basics of the lens designs were laid down between the end of the 19th and the first 20-25 years of the 20th century.
I think one can safely say that whatever lens design came after, it was a derivation from the basic optical schemes invented in those times: the triplet, the planar, the ernostar/sonnar, the tessar.

Since the 20s, the major advancements was in the materials more than in the optical design. Lens coating, more and more refined optical glass.

I think the most important advancement in optical design after the aforementioned optical scheme of the old times, was the invention of the floating elements inside lenses, to optimize performance at all focusing distances. I think Erhard Glatzel was the one who first did that, but I am open to correction if not.

Computers aided of course in the speed - before computers, a lens computation could have taken (and sometimes did take) up to two years of calculations and sometimes even more!

I think one important thing to keep in mind is, lenses are business. So not always there is a progress as the times advance. It depends on the maker and on the market. Lenses are subject to a number of compromises: design time (a company can not pay designers for too long time on one single lens), cost of raw materials, manufacturing costs, etc.
For instance, there is evidence of fantastic lens prototypes that never saw the production light, because of budget and marketing reasons: one of the most famous, having reached almost mythological status, was Glatzel's Distagon 25mm f/1.4.
You can read about it here:
http://www.luciolepri.it/lc2/marcocavina/articoli_fotografici/Glatzel-1,4-25/00_pag.htm

So the lenses that we have today, are not necessarily better (nor necessarily worse for that matter) than the older lenses. They are simply the result of what marketing research and cost/profit prospects have generated for today.
The moral is: one has to evaluate each lens individually: impossible to set a pattern.

[visualopsins]

Faster computers have helped lens evolution in at least five areas:

1. modeling -- designers can experiment with changes without having to produce a physical example to evaluate results.
2. zoom range -- increased computation speed has enabled complicated multi-element designs that would take years or even centuries to calculate and refine by hand.
3. aspherics -- increased computation speed enabled calculation of variations in individual element curvatures that benefit optical aberration corrections.
4. manufacturing -- computer-controlled lens grinding machines are much more accurate than hand grinding or non-computer-controlled grinders, and enable precision variations in curvatures, such as for aspheres.
5. cost reduction -- used to optimize materials use and manufacturing costs, not always beneficial to increased performance.

[Nikos]

[aoleg]

Computer-aided design you say... Well, I've got a very modern (developed and manufactured in 2010) Chinese Mitakon 85/2.0 lens. Sure enough, it's calculated with the most modern computers. It's still a classic Planar design of 6 symmetric elements. Its performance? Low resolution at f/2 and 2.8, field curvature beyond extreme, but high contrast and true colors (thanks to good coatings). I say, pre-war Sonnar 85/2 has an edge in performance here - except everything related to coatings (e.g. the modern lens has nire faithful colors, higher contrast and less flare).

[Esox lucius]

Generalizing is generally speaking a bad idea. Categorically speaking, I don't think today's newest designs by Canon/Nikon outperform older lens designs.

I am however convinced there exists a large number of modern design pro lenses, against whom the older Zeiss designs technically speaking stand no chance. The 14-24/2.8G AF-S Nikkor blows every other wide-angle out of the water, including the modern Z* SLR line. I am convinced the new 24/1.4G and 24-70/2.8G are two more modern wonders. Improved coating etc. also deliver razor-sharp telephoto lenses like 200-400/4G, 200/2G, 300/2.8G, 400/2.8G, 500/4G, 600/4G which do not have counterparts - certainly not in performance and often not even in line-up. Modern zooms have come far, outperforming older top primes already in the mid 1990s (17-35/2.8D Nikkor).

I can't speak of the Canon's glass as I have personally too little experience, but my Canon colleague's give similar testimonials.

An area where the modern lenses cannot and will not outperform the older designs is in fingerprint and dimensionality. While colors are more signature than realistic, the dimensionality and natural look in images from some of these classic designs is on a level no complex modern design can achieve. The more glass elements you put between the subject the more correcting elements you have to add, and consequently the less dimensional images you achieve. I find the Nikkor 50/1.4G AF-S one of the few modern lens designs which in best hands can deliver 3D which even comes close to the older Zeiss designs.

[egidio]

modern lens, for instance canon L can outperform most old lenses, but there are some of incredible old lens which can hardly be replaced. And that's not takumar 50 1.4 or similar, I'm talking about some lens that still costs 500+

And we still have modern zeiss lens which has similar signature as older lens.

I agree with Nikkor 50/1.4G AF-S, I have seen a lot of awesome samples.

[kansalliskala]

[poilu]

[Attila]

[trev]

Surely where most of the modern time & money for R&D and CAD goes into ZOOM lens designs as most prime lenses havn't advanced that much apart from coatings??

[Attila]

[AhamB]

[RioRico]

[visualopsins]

Thanks RioRico for reminding me, I've been meaning to post about lens design softwares. I forget where I first heard of this, maybe here, maybe FM55; thanks to whomever posted about it.

http://www.opticalsoftware.net/index.php

The free WinLens3D Basic and the PreDesigner are a lot of fun to play with if you are into lens design...

There is also OLIVE (not free): http://www.edmundoptics.com/onlinecatalog/displayproduct.cfm?productid=2118

[BRunner]

I think the biggest leap was made at the end of '70 and during '80 with emergence of new low dispersion glass materials (Leica APO-TELYT 180 was first in 1975) and aspherical surfaces. During '80 and '90 Leica introduced a lot of APO lenses for R system.
1975 3,4/180 Apo-Telyt
1984 2,8/280 Apo-Telyt
1987 2,8/100 Apo-Macro-Elmarit
1992 2,8/400 Apo-Telyt
1994 2,0/180 Apo-Summicron
1994 4,0/280 Apo-Telyt
1998 modular system APO-Telyt-R 1:2.8/280, 1:2.8/400, 1:4/400, 1:4/560, 1:5.6/560, 1:5.6/800
1998 2,8/180 Apo-Elmarit
2002 2/90mm APO-Summicron ASPH
Not to mention the APO and APSH lenses for Leica M system. For the new S-system Leica develops strictly ASPH or APO primes.
After my experiences with APO-TELYT 3.4/180 I can't imagine how this lenses can be even improved (I know the APO-Summicron and Elmarit are reportedly better), it clearly outresolves 14Mpx sensor of my camera even wide open, not to mention the lack of CAs. The 2.8/100 Macro-Elmarit is considered best ~100mm macro made till this time - after almost 1/4 of century. But the quality comes at price.

Zeiss philosophy is to make competitive lenses without using special materials to keep prices "down". Till this time, they are still better than most of their competitors and in comparison to Leica, the lenses are truly affordable.
I think that in '70 Zeiss reached the level, where next improvement without using LD glass or ASPH surfaces is almost impossible. Unfortunately, at least longer focal lengths are impossible to correct to Leica (or APO Lanthar) levels without using those materials. Compare CAs of 23 years old 100mm APO-Macro and new 2/100mm Makro-Planar.

Pentax for example goes different route. Develops very compact primes with very good performance. Sure, not on pair with Leicas or Zeisses but for weight of one wide-angle Distagon 2.8/21, you can take complete prime set of Pentax Limiteds (DA15, 21, 40, 70). 600g Distagon vs. 587g Limiteds combined.

Canon developed lot of LD and ASPH prime designs too. But I'm not much into this system, so I can't comment. Ditto Nikon.

But the truth is, most R&D now goes to zooms.

[ylyad]

[Nikos]

[Esox lucius]

[AhamB]

[cooltouch]

The LTM 50mm f/3.5 collapsible Elmar is still the sharpest lens I've ever seen and/or used. In this thread, one owner documents 112 lp/mm with his copy:

http://photo.net/leica-rangefinders-forum/00LqNX?start=10

Click here to see on Ebay

[Anu]

A couple of interesting points:

* Today's lenses can't use all the materials which were used in the old days and vice versa.
* In the past the lenses didn't have to worry about AF, so focusing was easy to achieve by moving all the elements, avoiding changes in the optical formula.

IMHO, the three biggest practical changes have been the spread of very good zoom-lenses (70-200/2.8's and so on), and reduction of colour aberrations and shorter minimum focusing for tele-lenses. The strongest of old primes are still truly excellent performers, apart from often somewhatt strong axial CA or spherical aberrations.

I am sleepy, so anything I said above may be even more stupid than what I normally write.

[Edgar]

i find interesting the fact that Zeiss when releasing their new primes, even the very expensive video ones did not change the optical formula in majority of them. They did, however, improve the coating. Question is if they did this to preserve the old school look or just did not think they needed much improvement. What about adding a few fluorite and aspherical elements? I have read somewhere that Zeiss does not always mention what exotic glass goes inside their lenses. On the other hand, the new Sony Zeiss says it has lots of the stuff inside. Often I wonder, though, if this special ZA line is really better than the classic ZF? In some respects yes, in some no. All in all, it seems the new elements have not given a huge advantage in this case.
ps. IMO the Zeiss 100mm f2 would have benefited from APO

[visualopsins]

Exotic lens materials have different thermal coefficients of expansion, i.e. useful temperature range is often reduced because of increased material expansion/contraction with temperature:

http://www.edmundoptics.com/technical-support/optics/optical-glass/