Home

Please support mflenses.com if you need any graphic related work order it from us, click on above banner to order!
SearchSearch MemberlistMemberlist RegisterRegister ProfileProfile Log in to check your private messagesLog in to check your private messages Log inLog in

Are 'Made by Rollei' HFT lenses Carl Zeiss glass design?
Post new topic   Reply to topic
Home   Manual Focus Lenses
View previous topic :: View next topic  


PostPosted: Tue Nov 10, 2015 5:19 pm    Post subject: Reply with quote
Where did you find this info?

Marco Cavina says they are the same:

http://vintage-camera-lenses.com/carl-zeiss-planar-history-part-2/

Quote:
In those years Rollei requested a new, faster 50mm to be offered as a premium alternative to the f/1.8 model. Again, Zeiss didn’t recycle the old (and somewhat unimpressive) Contarex Planar 1.4/55 nor the 1963 1.4/50 prototype. A new lens was designed from scratch by Karl-Heinz Behrens and Erhard Glatzel in 1972. This new 50mm f/1.4 was later purported to the Contax system (both the standard and the autofocus N-mount) and, with minor modifications, to modern DSLR: it is substantially the same Planar 1.4/50 currently marketed as ZE (Canon), ZF (Nikon) and ZK (Pentax).


Here is the layout and patent info:

Quote:


7- linsiges Planar (erweiterter Gauss- bzw. eigentlich Ultron-Typ; da die der Blende vorn zugewandten Elemente einzeln stehen)
1.4/ 50mm
7 Elemente / 7 Gruppen
Patent Nr. DE-2232101 vpm 30.6.1972 (Anmeldedatum)
Karl-Heinricht Behrens, Dr. Erhard Glatzel


PostPosted: Tue Nov 10, 2015 5:37 pm    Post subject: Reply with quote
Rollei sales brochure/ads:
http://www.fuwen.net/index.php/home/rolleiflex-35mm-slr/50-f1.4-hft-planar
Rollei SL 35 ME manual(scroll down to last page of the pdf).
http://www.butkus.org/chinon/rollei/rollei_sl_35_me/rollei_sl_35_me.htm

The back focal distance is 37.7mm. Both mentioned the angle of view is 46 degrees.

Manual of Contax 50 1.4
https://www.zeiss.com/content/dam/Photography/new/pdf/en/downloadcenter/contax_yashica/planar1-4_50mm_yashica_e.pdf



PostPosted: Tue Nov 10, 2015 5:42 pm    Post subject: Reply with quote
I don't think a catalogue is a very valid source, Patents and Zeiss published data sheets would be more valid.

As for the angle of view being 46 or 47 degrees, that's not telling us much as it probably means they rounded up or down , just as the Minolta 2/45 and Konica 1.8/40 and both 43.2mm but one maker rounded up and the other rounded down.

That 38mm figure for the back focal distance is nonsense, simply not possible - the rear of the lens would protrude 7mm and block the reflex mirror. Maybe it's a typoe and they meant 48mm.


PostPosted: Tue Nov 10, 2015 5:46 pm    Post subject: Reply with quote
In case someone need a side by side comparison of both lens http://blog.xuite.net/gengjaw.sheu/tessar/62385259-%E4%BE%9D%E7%84%B6%E6%98%AF%E5%80%8B%E8%AC%8E%E9%A1%8C+Carl+Zeiss+Planar+50mm+f1.4+Rollei+QBM%E6%8E%A5%E7%92%B0 .

P.S. The rear element on the Contax version seems larger than the rollei version. To be more accurate, it will be better to remove the element from the lens for a direct comparison. Laugh 1


PostPosted: Tue Nov 10, 2015 5:57 pm    Post subject: Reply with quote
How about performing a verification test? Use the same camera(e.g. A7 series) with both lens focus on infinity. This will be the easiest way to determine if they are the exact lens. The person in the link above found there is slightly change of the viewing angle when he tested both lenses. We can re-run the test.

Update:
Although I believe the HFT Distagon and T* Distagon is exactly the same lens, the information on the brochure say the AOV of the former is 80 degrees and the later is 82 degrees. Rolling Eyes


PostPosted: Tue Nov 10, 2015 6:43 pm    Post subject: Reply with quote
FOV is going to differ from lens to lens as the focal length will differ. You might have seen on repro lenses, the precise focal length is usually marked on the lens block somewhere.

When you make a batch of lenses, say, 50mm, they do not all measure the same focal length, there is some spread, due to manufacturing tolerances. For example, one lens might be 50.7mm and another 51.4mm, despite being the same design made at the same time and place.


PostPosted: Tue Nov 10, 2015 8:12 pm    Post subject: Zeiss list of prototypes is the key Reply with quote
The reasonably accurate list of all Zeiss lenses, numbers, dates and which prototype number . should settle this debate.

If a new type of glass or slightly different radii were used, it would have a note in the list, usually stating what camera it would fit.

I do not have time to look it up right now, but assume that other members also have the book with the lists.

p.


PostPosted: Tue Nov 10, 2015 9:36 pm    Post subject: Reply with quote
iangreenhalgh1 wrote:
Everything I've read says the QBM and C/Y 1.4/50 is the same lens. I only have a QBM so can't confirm or deny.


I pulled out my box o' planars and they are definitely not the same - C/Y 50/1.4 has a visibly smaller front element and significantly larger rear element.


PostPosted: Tue Nov 10, 2015 9:37 pm    Post subject: Re: Zeiss list of prototypes is the key Reply with quote
paulhofseth wrote:
The reasonably accurate list of all Zeiss lenses, numbers, dates and which prototype number . should settle this debate.

If a new type of glass or slightly different radii were used, it would have a note in the list, usually stating what camera it would fit.

I do not have time to look it up right now, but assume that other members also have the book with the lists.

p.


Zeiss site has the data for all lenses they consider their own. C/Y is there, Rollei is not.


PostPosted: Tue Nov 10, 2015 9:47 pm    Post subject: Reply with quote
Rollei is a famous lens manufacturer ...
Everybody may name a lens Planar...


PostPosted: Tue Nov 10, 2015 10:26 pm    Post subject: Reply with quote
memetph wrote:
Rollei is a famous lens manufacturer ...
Everybody may name a lens Planar...


Rollei lens does say "Carl Zeiss" on it.
I am fairly certain that "Planar" is a registered trademark, so, no, only Zeiss and its licensees can use the name.


PostPosted: Tue Nov 10, 2015 11:14 pm    Post subject: Reply with quote
iangreenhalgh1 wrote:
I don't think a catalogue is a very valid source, Patents and Zeiss published data sheets would be more valid.


I would hesitate to dismiss a detailed brochure produced by the camera manuacturer from being "a very valid source". I certainly can't think of any professional historian who would dare to make such an uncritical assumption. He, or she, would begin by supposing that the source is probably correct but would then look for other evidence to support or undermine it. The historian's job gets really interesting when evaluating conflicting evidence. In this case we have to begn by allowing that there is as much chance of typographical error in a Zeiss data sheet as there is in a Rollei catalogue. Without other hard evidence it simply isn't good enough to assert that "a" must be right and therefore "b" must be wrong - we need to ascertain if there actually is a difference in the artefact as opposed to a discrepancy in the descriptions. And, by the by Ian, as a matter of general interest, don't assume that patents invariably tell the truth, the whole truth and nothing but the truth.They frequently contain whatever critical elements the applicant needs to protect, but not necessarily the whole recipe for successfully producing an entire product.

What intrigues me in cases like this is why such dissimilarities may occur.. In other words, what's the story behind them?


PostPosted: Wed Nov 11, 2015 4:28 am    Post subject: Reply with quote
I know that every lens comes out from the factory will have slight different focal length. For some budget lens, the percentage different of the focal length may be up to several percent. This may not be an issue of a SLR lens. However, it will affect the focus accuracy of rangefinder lens if the focal length differ from the design focal length too much.

Here are the diagram from the patent US3874771(DE2232101) and the diagram from Zeiss. I can't align/scale them perfectly and this is the best I can do. The soild one is the Contax version.


To my eyes, they share the same design but radius of curvature of individual elements are different(assume both diagram are accuracy).


PostPosted: Wed Nov 11, 2015 5:54 am    Post subject: Reply with quote
While the overall layout might be the same, if the curves are different than the design has been recalcualted and they are no longer the same design.


PostPosted: Wed Nov 11, 2015 11:39 am    Post subject: Reply with quote
iangreenhalgh1 wrote:
While the overall layout might be the same, if the curves are different than the design has been recalcualted and they are no longer the same design.


I think we may have a problem of semantics here . . . are we getting confused by using "design" to signify what are really two different things? We may talk of a lens as being a "Planar design" or a "Tessar design" even though the formulation (or "design") of a particular iteration may differ from others of the same pattern in its details such as glass types or curves or distances between elements. If we spoke of a 'Planar (or whatever) pattern" it might make things easier to follow for those of us who (like me) who have only the most basic grasp of technical optics.

The two schematics so neatly shown by Calvin are clearly of the same pattern, but the individual designs are obviously different.


PostPosted: Wed Nov 11, 2015 1:01 pm    Post subject: Reply with quote
It's about correct use of English. An individual lens design may be of a type.

Make any changes to that design and you have a new design.

Therefore, if some changes were made to the 1.4/50 when the C/Y version was introduced, then it's a new design and the QBM and C/Y version are two different designs.


PostPosted: Wed Nov 11, 2015 2:12 pm    Post subject: Reply with quote
Gardener wrote:
memetph wrote:
Rollei is a famous lens manufacturer ...
Everybody may name a lens Planar...


Rollei lens does say "Carl Zeiss" on it.
I am fairly certain that "Planar" is a registered trademark, so, no, only Zeiss and its licensees can use the name.


It is what I ment.
I know only this 1.4 branded Car Zeiss and the 1.8 is not a Rollei lens , it was just produced by Rollei. It can be considered as a Zeiss lens even it would not be in their official catalogue.


PostPosted: Wed Nov 11, 2015 5:04 pm    Post subject: Reply with quote
iangreenhalgh1 wrote:
It's about correct use of English.


Indeed it is. Or rather about the uniform use of terminology. The problem with this sort of "English" is that we all need to use terms uniformly and there does not seem to be any established standardisation of terms in this particular context. Maybe other languages are less imprecise?


PostPosted: Thu Nov 12, 2015 11:38 am    Post subject: Zeiss planar facts Reply with quote
I just looked up the list of Zeiss lens designs (Thiele 2006, 2nd. printing). The list states that for the Planar:

The contarex 55\1,4 was calculated 18.06.1959 when 2 samples were produced with deliveries starting in 1964.

There was a 50\1,4 calculated 16.03.1972 for Rollei SL35 with deliveries in 1974 from number 4948191.
A 50\1,4 was calculated 02.04.1973 for the Weber SL75 and delivered in 1974
Another 50\1,4 was calculated 19.07.1973 for Arriflex and delivered in 1974

The list then has a very strange record of the version delivered for the Contax bayonet: a calculation dated 29.05.1981 and delivered as two samples in 1974, with production in Japan starting in 1976 with number 5816827. Since the Contax RTS was lauched at Photokina 1974 only a time-machine could have obtained its lens design from 7 years into the future, so the numbers must be mixed up in this case.

p.


PostPosted: Thu Nov 12, 2015 11:49 am    Post subject: Reply with quote
Even there is an error in the date, at least we know that there is another calculation for the Contax system. Thank you!
Post new topic   Reply to topic
Home   Manual Focus Lenses
Goto page Previous  1, 2
Page 2 of 2