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Zeiss T* vs. Pentax SMC coatings
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PostPosted: Sat Dec 22, 2012 4:15 am    Post subject: Reply with quote
iangreenhalgh1 wrote:
Peter, I'm not clear on the Pentax-Zeiss co-operation, I have yet to see any info on the dates of this co-operation, just vague info about it being around the time of the end of Contarex production, which was sometime in 1971. The first Zeiss lesnes with T* coatings were released in the autumn of 1972, so sometime between the end of Contarex lens production and autumn 1972 is when Zeiss developed T*.

hifisapi wrote:
This isnt about "brand loyalty" this is about technology, My contention is that PENTAX had superior multicoating
technology in the '70's and thats that. Until someone can produce some hard evidence to the contrary, which
no one has, then I have to stick to my position on the matter. Now you can claim that the early Zeiss T* coatings
were just as good even though Pentax held the patent if you want, but Im not going to change my positon just
based on your undocumented contention. Patented is more "proof" than no proof other than subjective t* user
experiences. As for the original thread that started this discussion, I own two different (M42 and KA) copies of the
SMC 15/3.5 and considering the huge exposed front element and the very high number of lens elements in the
design, the contrast, saturation, and general flare resistance is excellent for its class of lens, a testiment to SMC
and the lens probably wasnt even possible to produce until the smc era which it wasnt.


Again, you are ignoring a huge body of evidence, I keep telling you how many people here have T* lenses and the vast number of sample pictures and reports. That is a massively strong counterargument to your contention that Pentax had better coatings. So it's far from an undocumented claim. Look at some sites that have MTF information for Hasselblad Zeiss T* lenses and Pentax 67 SMC lenses, then tell me the Zeiss coating is inferior, or look at MTF information for Contax Zeiss T* lenses and Pentax SMC lenses, again, there is a very large amount of information available that contradicts your viewpoint. You just have to be prepared to accept it, which you don't seem to be.

Your point about the necessity of SMC to enable the production of an ultrawide lens is incorrect. I own a 2.8/18mm lens made in 1961 by LOMO in Leningrad, it has the typical purple/magenta Russian coating and it has excellent contrast and saturation, flare resistance is also good as long as there isn't a bright light source in the frame such as the sun. Certainly comparable in those regards to the much later multicoating Tokina AT-X 3.5/17. The front element is much bigger than the Pentax 3.5/15. There are other examples of very complex wide angle lenses that perform very well without having sophisticated multicoatings. There are other factors to consider such as the internal mechanical design - light baffles, anti-reflective paint surfaces, glass types, number of air-glass interfaces, size of entrance and exit pupil. As Attila said, there are plenty of single coated lenses that are superb performers and can match later multi-coated optics.

Pentax had very high standards, Im sure they wouldnt bother producing such a wide 15mm lens with so many elements without high performance multicoating.
15mm is significantly wider than 18mm so flare is harder to control and when the sun is in the frame is what Im talking about where pentax is better. And Im not trying to argue which lenses are better, Pentax or Zeiss, Im just stating the quality of coatings from Pentax was better in the 70's. Your last argument seems to be discounting the benefits of great multicoating. Of course there are other factors in flare control but the more air glass surfaces there are the more benefits of multicoating. That cannot be denied.


PostPosted: Sat Dec 22, 2012 5:31 pm    Post subject: Reply with quote
This is the point where I give up because you're never going to learn anything with such entrenched views and blinkered vision. Congratulations, you won through sheer pig-headedness.


PostPosted: Sat Dec 22, 2012 5:59 pm    Post subject: Reply with quote
Arguing/discussing/debating who invented what or has the best/superior technology is futile. It is pictures which count. Is it better to go out looking for good pictures or going out looking for challenging situations which which to prove how good a lens is? Some of my most pleasing results over the last few years show barrel distortion and CA (if you look at a big enough copy), but the other merits help me overlook the shortcomings of the lens.


PostPosted: Sat Dec 22, 2012 6:12 pm    Post subject: Reply with quote
iangreenhalgh1 wrote:
This is the point where I give up because you're never going to learn anything with such entrenched views and blinkered vision. Congratulations, you won through sheer pig-headedness.


You tried. Big time. Sometimes it's like p$%^&*g into the wind. And I see in other threads that this is a very persistent wind......


PostPosted: Sat Dec 22, 2012 6:58 pm    Post subject: Reply with quote
I've just wasted 10mins of my life reading this thread and it all boils down to:-

When Pentax introduced their first Super multi coating method\technique, was there anything better at the time or previously...answer yes or no Rolling Eyes


PostPosted: Sat Dec 22, 2012 9:04 pm    Post subject: the curates egg Reply with quote
the English have a tale about a clergyman being served a rotten egg. He said, "parts of it areexcellent". This opinion on the "curates egg" seems appropriate here. The thread has three equally legitimate parts, and people might get less upset by regarding one at a time. It needs to be realized that this netsite has technical , "antiquarian" AND pictorial aspects-.

The first issue is "who invented multilayer lens coating". Not just who was the first to write up fractional lambda coatings, but who actually applied them, and when.

Afficionados know that "blooming" was replaced by one layer to reduce reflections, but it is always interesting to know who then used which oxides on top of each other to improve matters. I for one, had never heard of the NASA contract mentioned here, so thanks for posting. (References?)

The second issue is, who invented and applied superior multilayer coatings in full production (e.g. Fuji, Asahi), how many layers and why (eg. Fuji v\s Asahi and others), which compounds, how robust (eg. early v\s late Leica (Meopta?) televid 77- coatings). Here it seems that definitions of "first" and "superior" diverge. When this is sorted, one can leave the technical bits and proceed to why this is at all interesting for taking pictures.

Here, the proof of the pudding is in the eating. IF the end result serves its purpose, whether taken through the bottom of a soda bottle, with your latest Coastal Optics, your vintage Kinoptic or your mass produced plastic wonder, it is the picture that needs to be judged. Granted, your chances of higher contrast increases with coatings (but also with design and production tolerances), while pp- adjusting colours with a bit more black may sewrve to neutralize substandard coats.

I would appreciate the adversaries here sticking to their guns (and providng references), not to give up, but to make crystal clear what they are on about.

p.


PostPosted: Sat Dec 22, 2012 11:45 pm    Post subject: Reply with quote
hifisapi wrote:
This isnt about "brand loyalty" this is about technology, My contention is that PENTAX had superior multicoating
technology in the '70's and thats that. Until someone can produce some hard evidence to the contrary, which
no one has, then I have to stick to my position on the matter.


To say that something must be true until someone else can provide evidence to the contrary, is no argumentation.
Someone could then just as well say that he can fly, or that Elvis lives in a space station orbitating around Saturn, or that Hitler survived WWII for 20 years
and made a living out of making carpets in Baghdad, and until someone can produce hard evidence to the contrary these assertions can not be disputed... Laughing
This debate is devoid of any seriousness. It's just junk talk and only a potential flame riser. Therefore, I lock the thread. Sorry.
The topic of this discussion may be talked anew in another thread but only if a more serious approach will be taken.
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