Zeiss ZM Sonnar 50/1.5

[bj_rn_roth]

Zeiss has announced the Sonnar 50/1.5 in M-mount.

 

http://www.rangefinderforum.com/forums/showthread.php?p=320534#post320534

http://www.zeiss.com/photo

[stephen_jones4]

interesting aperture blades...

[kristian dowling]

MTF graphs 'suggests' that f/4 performance is lower than the Summilux 50/1.4 ASPH at f/1.4....and only focuses to 0.9m.

 

But it is smaller and quite compact, and real world results may be better than the MTF graph 'suggests'.

 

IMHO, a possible waste of time realeasing this lens with an average MTF and 0.9m alone. There are so many other 50mm lenses around, so unless the performance is stellar like the other Zeiss lenses which 'are comparable' to the Leica M equivelents, most people may just pass it up. Stats 'suggest' otherwise....

[bj_rn_roth]

I could well imagine that this lens would be significantly cheaper than a 50/1.4 ASPH, but I don't know, of course.

[john_shriver]

I doubt that this lens is intended to compete with the 50/2.0 Planar, or the Summicron or Summilux APSH in terms of sharpness. Note that the MTF graphs for their own ZF Planar 50/1.4 are superior.

 

The 50/1.5 Sonnar design is pleasantly soft in the corners wide open.

 

It is more about the "Sonnar look", which is distinctive, and can be very nice.

 

However, it isn't the same formula as the orignial Sonnar, as it's in 4 groups, not 3. Presumably T* coatings give them that flexibility, and it may simplify manufacturing. As is, I'm sure that rear group of three elements is no fun to make.

 

Considering the grubby soft aluminum mounts that the post-war LTM 50/1.5 Sonnars were sold in, and the mechanical issues that even afflict the Sonnars for the Contax, I think this was a very thoughtful thing of Zeiss to do.

 

It will be interesting to see pricing, it may be more expensive than folks expect.

[kristian dowling]

Maybe it won't compete directly with the lenses you mentioned, but in some ways it will. The 'Sonnar look' you talk about really has no purpose as this is an updated lens with a new formula and coatings - Sonnar is just a way to brand/market the product.

 

It will probably compete directly with the VC Nocton, which it will probably lose, but it seems quite compact compared. I think it would sell for a bit above the 50/2 Plannar, so it will compete directly against the pre-ASPH Summilux 50, of which I'd take, if that was my price level. 20cm focus distance loss is a pretty big deal....but I guess they don't want people to make focus errors at 0.7m then complain of having an unsharp lens....it happens.

[Karim Ghantous]

If there's one thing that lens makers get wrong all the damned time it's aperture blades. I can't believe that after a century of 'progress' we still don't see near-round diaphragms on all new lenses. It cannot be that hard to do - I think the reason why we are getting ripped off here is because of sheer stupidity.

 

While perving at Stanley Kubrick's personal Zeiss lenses (the high-speed ones) I noticed that they had triangular apertures. Now when I see an ad or movie I can tell what lenses they are using by those damned triangular flare highlights.

 

I've seen pre-WW1 lenses that have nice, beautiful, round apertures. I've also seen third-party LTM lenses with about 12 blades or more. It's like those people who can't even make tea properly. You don't need to be gifted - you just need to think just a little bit. IT IS NOT THAT DIFFICULT SO JUST DO IT RIGHT FOR GOODNESS' SAKE.

[paul t]

Ain't it great there are all these experts around to tell Zeiss how to do it?

Those aperture blades look identical to my 50s Carl Zeiss Sonnar; they take

on something of a star shape around f/4 but are circular at smaller and larger

apertures. I have never noticed star-shaped highlights using this lens. <p>

[john_shriver]

I've seen pictures taken with the Canon RF lenses with the diapraghms that that go star-shaped, and there is evidence of star-shaped specular highlights.

 

I suspect that funky blade shape is helpful in reducing the overall lens size, which is a stated goal for this lens. It might also make it easier to make the f-stop scale linear, which appears to be one of Zeiss' design goals on these lenses.

 

As for "Sonnar" only being a marketing name for this lens, I don't think so. That rear three-element group is very much distinctively the core of the 50/1.5 Sonnar formula. It's also very demanding in tolerances on making the elements, so this lens may be a good bit pricier than the ZM 50/2.0 Planar. But no way will it be as expensive as the Summilux ASPH, you have to make lenses in Germany to have them that expensive, and this is almost certainly being made by Cosina in Japan. It probably was even Hirofumi Kobayashi's idea to do this.

[Aoresteen]

I agree with John who wrote:

 

"It probably was even Hirofumi Kobayashi's idea to do this."

 

Mr. K knows classic lenses for sure!

 

It is good news/bad news for me. As I like the 50mm Sonnar 1.5, I had a '52 Contax IIa and 50mm Opton Sonnar 1.5 restored last year (not cheap!). Now I have a choice to get one that is T* coated. Yikes! So many lenses, so little time!

[max_fun]

It does look very compact, and I can see using it as my general lens instead of my 50mm 'Cron. When it comes to my RF lenses, I'm all about the size. Which is why I'm still keeping my 35mm 'Lux.

[miles_s.]

"No. of elements/groups: 6/4" and they still call it a Sonnar ;] Facetious comments aside I have to say that I like to look and specs of this lens. Now if I could only get an example to test.

[alan_wilder1]

The 6/4 optical design is asymmetrical in layout similar to the Rollei 35S 40/2.8 Sonnar except the rear group is a cemented triplet instead of a cemented doublet. The 1st three elements are single air-spaced resulting in a 1,1,1,3 group configuration as seen here: http://www.zeiss.com/C12567A8003B8B6F/EmbedTitelIntern/CSonnar_1.5_50_ZM.EN/$File/CSonnar_1.5_50_ZM.EN.pdf

[james_cooke]

"The 'Sonnar look' you talk about really has no purpose as this is an updated lens with a new formula and coatings - Sonnar is just a way to brand/market the product."

 

It appears in your new found "professional" career you havent used many Sonnar lenses then.

 

Given that this lens will be half the cost of Leicas latest, this new and compact modern incarnation of that Classic Sonnar will be most welcome to alot of Zeiss devotes. It will have the smooth Bokeh of a Pre-ASPH Summilux with the flare resistance of modern T* coated lenses, I can imagine quite a few going for that.

[richard_s.]

Old 50mm Sonnar lenses had a very high image quality. <br>

<br>

Much better than that awful late 1970s fast 50mm lenses. Those designs

tried to cheat in the primitive resolution test in the amateur

photographer press, by trading image quality and bokeh for horrible

"donut type" highlights and confusing  "double line"

backgrounds.<br>

It was cheating, since price and technology did not allow for proper

correcting of the lens aberrations.<br>

Those lenses had a lot of problems with internal reflections, flair due

to the large number of lens elements and insufficient coating

technology (not significant better then that of Zeiss in the 1930-40).<br>

<br>

The old Sonnar lenses had only 3 lens elements, like Tessars which

helps a lot with contrasty

light situations in the real world  (not in that stupid tests

like photographing a map in the garage).<br>

<br><div></div>

[john_shriver]

Interesting to compare the block diagrams -- I'd say they replaced one element in the front group with an "air lens". Not a strange idea, the original Summicron used an air lens as well.

 

The practicality of air lenses depends on lens coating, and Zeiss probably stuffed glass in there in the original uncoated Sonnar to reduce flare.

 

The Summicron, on the other hand, was the first Leitz 50mm lens designed with the assumption of coating.

[vivek iyer]

"The old Sonnar lenses had only 3 lens elements, like Tessars which helps a lot with contrasty light situations in the real world"

 

Richard, How do you count the elements in a lens from a block diagram?

 

Hint: A Tessar is a 4 element 3 group lens.

[fred_c1]

>If there's one thing that lens makers get wrong all the damned time it's aperture blades. I can't believe that after a century of 'progress' we still don't see near-round diaphragms on all new lenses. It cannot be that hard to do - I think the reason why we are getting ripped off here is because of sheer stupidity.

 

It'd be a whole lot different if it came from the right brand:<div></div>

[miles_s.]

"The 6/4 optical design is asymmetrical in layout similar to the Rollei 35S 40/2.8 Sonnar except the rear group is a cemented triplet instead of a cemented doublet." And same as the M mount 40mm/2.8 Sonnar HFT, as well.

 

Vivek, anyone can make a "slip of the pen/finger/tongue" and refer to an element instead of a group or vice versa. Indeed, some patent and patent classification schemes call groups lenses. That said, the group/element language is more precise. Even if coating has made the Sonnar erstwhile.

[vivek iyer]

Miles, Thanks for the clarification and the quote.

[richard_s.]

<i>Hint: A Tessar is a 4 element 3

group lens.</i><br>

<br>

Oh yes, you are right it´s <b>3

groups</b> in Sonnars and Tessars,

how stupid of me.<br>

<br>

Just in case, those awful 70s lenses had much more <b>flare</b>

than flair.<br>

<br>

[vivek iyer]

Richard, I read selectively. The group/element numbers stick out and do flare out anything else you typed.

[todd_phillips1]

Can someone provide a link to this lens? I've gone to the Zeiss site but can't seem to find it.

 

Thanks in advance!

[miles_s.]

See link in Alan's post.

[kristian dowling]

James Cooke , jun 15, 2006; 02:18 p.m.

"The 'Sonnar look' you talk about really has no purpose as this is an updated lens with a new formula and coatings - Sonnar is just a way to brand/market the product."

It appears in your new found "professional" career you havent used many Sonnar lenses then.

 

Given that this lens will be half the cost of Leicas latest, this new and compact modern incarnation of that Classic Sonnar will be most welcome to alot of Zeiss devotes. It will have the smooth Bokeh of a Pre-ASPH Summilux with the flare resistance of modern T* coated lenses, I can imagine quite a few going for that.

 

James considering you know as little as I do about the actual performance of this lens, you are assuming just as much as I am....probably wrong, but fun!

 

Infact I am glad haven't bothered to 'use many Sonnar lenses in my new profession', cause I've learnt a hell of a lot learning more beneficial things. But thanks for caring, very sweet indeed.