IF a fast ZM 50mm came out - f1 or f1.2?

[sanmich]

Interesting point. Of course for a modern AF lens, that's the sort of information that's on the chip, and (assuming the engineers have done their jobs) the camera compensates.

the hexar AF does just that.
as far as I understand, overcorecting a lens yields focus shift, so any lens in a mechanical mount is the result of a trade off.
The AF lens, on the other hand can be highly corrected, and the resulting focus shift corected via the focusing software.
IIRC, that explains why it's impossible to mount the brilliant Hexanon 35 f/2 of the AF in M mount as it is done with contax lenses.

 

[Roger Hicks]

the hexar AF does just that.
as far as I understand, overcorecting a lens yields focus shift, so any lens in a mechanical mount is the result of a trade off.
The AF lens, on the other hand can be highly corrected, and the resulting focus shift corected via the focusing software.
IIRC, that explains why it's impossible to mount the brilliant Hexanon 35 f/2 of the AF in M mount as it is done with contax lenses.

How do you 'overcorrect' a lens?

Cheers,

R.

 

[Roger Hicks]

I don't know about over rated and very overpriced for the Canon 50/0.95. One has been available in the RFF classifieds last week and didn't sell @ $2400 (USD) and may still be available @ ~ 10% less. BTW, not my lens and I don't know the seller. What other full frame lens exists that will do f-1.0 or faster for under $3K?

But if it's soft and flary, and you want a sharp, contrasty lens (as most do), who cares how fast it is or what it costs? For me, that lens would be overpriced at $1000, and probably even at $500.

Cheers,

R.

 

[sanmich]

How do you 'overcorrect' a lens?

Cheers,

R.

you correct it too much? 😱

I guess that means correcting the optical aberrations to the point of inducing other unwanted behaviors like bad bokeh or focus shift?
Please correct me if I'm wrong...

 

[Kolame]

As far as I know, the thing called overcorrection is the try of the developers of a lens to make it as sharp as possible, if you oversharpen a lens, you get harsh bokeh, with doublings a the blurred thing out of focus. One lens I have, which is overcorrected is the Tamron 17-50mm 2,8 (first version).
Some examples from my Flickr-stream:
http://www.flickr.com/photos/cwpphoto/4805051343/in/set-72157624404496585
http://www.flickr.com/photos/cwpphoto/4805679688/in/set-72157624404496585
http://www.flickr.com/photos/cwpphoto/4805675614/in/set-72157624404496585
See what I mean?

 

[semilog]

As far as I know, the thing called overcorrection is the try of the developers of a lens to make it as sharp as possible, if you oversharpen a lens, you get harsh bokeh, with doublings a the blurred thing out of focus.

No. That's not right at all.

1. Correction is not merely for "sharpness" but rather for a whole series of lens aberrations (spherical, chromatic, etc.) as well as for geometric distortion.

2. Bokeh can be horrible on a soft lens and it can be great on an outrageously sharp lens. It's not as though there is a single slider available to lens deisgners, where if you increase sharpness you get worse bokeh.

This is not a trivial set of issues to think about. Zeiss has published a long white paper on the topic that's worth reading and thinking about if you are interested: [Zeiss PDF].

 

[Roger Hicks]

No. That's not right at all.

1. Correction is not merely for "sharpness" but rather for a whole series of lens aberrations (spherical, chromatic, etc.) as well as for geometric distortion.

2. Bokeh can be horrible on a soft lens and it can be great on an outrageously sharp lens. It's not as though there is a single slider available to lens deisgners, where if you increase sharpness you get worse bokeh.

This is not a trivial set of issues to think about. Zeiss has published a long white paper on the topic that's worth reading and thinking about if you are interested: [Zeiss PDF].

Exactly. "A lens" is a collection of attributes. Often, improving one attribute causes deterioration in another. Even then, you can't 'overcorrect' any single fault, which is what I was querying earlier. After all, what would 'overcorrecting' a given fault mean?

Cheers,

R.

 

[seakayaker1]

If Zeiss could produce a 50/1.0 at 1/3 the cost of the Noctilux like the 50/1.5 at less then 1/3 the cost of the 50/1.4 Summilux then they would find a market. The Noctilux has a following that would buy the lens if it was at a lower cost.

The projected number of buyers that may purchase a ZM 50/1.0 may not be at a point that Zeiss would believe it worthwhile after the effort/cost of R&D, manufacturing, marketing and sales.

I know if a ZM 50/1.0 hit the marketplace with positive reviews I would most likely find a way to purchase if it was in the $3500.00 price range.

 

[Kolame]

No. That's not right at all.

1. Correction is not merely for "sharpness" but rather for a whole series of lens aberrations (spherical, chromatic, etc.) as well as for geometric distortion.

2. Bokeh can be horrible on a soft lens and it can be great on an outrageously sharp lens. It's not as though there is a single slider available to lens deisgners, where if you increase sharpness you get worse bokeh.

This is not a trivial set of issues to think about. Zeiss has published a long white paper on the topic that's worth reading and thinking about if you are interested: [Zeiss PDF].

Thanks for the corrections. I thought of this special case, I know, that there’s not just parameter… Thanks for making that clear. And I meant this one special type of bokeh, with doubling figures in the oof-area, you can see in my images.

 

[JCdeR]

As I see it Zeiss is only interested in manufacturing and selling perfect lenses. Any ultra fast lens won't be all that good. Noctiluxes, although sexy aren't exactly the bees knees IQ wise.

 

[semilog]

As I see it Zeiss is only interested in manufacturing and selling perfect lenses. Any ultra fast lens won't be all that good. Noctiluxes, although sexy aren't exactly the bees knees IQ wise.

Well, with the current 50/0.95 that just ain't so. That lens has genuinely superb image quality. I think it's an absurd lens in pragmatic terms, but that's a qualitative judgement.

In technical terms it's shockingly good, just about miraculous when you consider its speed. Actually, it's remarkable that Leica was able to design that optic so that it could be manufactured and sold for only $10,000. That is by itself a pretty significant technical achievement.

But it's still an absurd lens.

 

[efirmage]

I used to be all about the fast lenses, but in reality shallow DOF does not suit my types of shots, and the faff with back focus and range finder alignment does not suit me either.

f/2 is plenty for me, and that means lenses can be small, light, and cheaper.

I agree. I never need less DOF for the kind of shots I do, so if I need faster I just up the ISO. I doubt Zeiss will venture into this side of the market. Their lens lineup seems to be fairly set going into the future.

 

[kram]

[QUOTTheir lens lineup seems to be fairly set going into the future.E][/QUOTE]
OK, I will settle for the 'most excellent' f2.8 lens, and use it as my summer lens🙂
With new digital cameras coming out every couple of months, with no real advantage over the competitors, I can't see why the camera manufacturers have such a quick turn over. With ZM lens we can see a gap in the market, but they don't seem to want to fill it. I wonder how much of Leica's profits were from their three fast lens (21mm+24mm f1.4 and 50mm f0.95)?

 

[KM-25]

I think I would pass since I have shrank all my glass down a stop for super compact uses, my 50/2 ZM is perfecto!

 

[italy74]

F/1 ! Doing something, let's do it good !

 

[jsrockit]

I'd like a Zeiss f/.85 that is about the size of a Perar Super Triplet.

 

[The Meaness]

If Zeiss could produce a 50/1.0 at 1/3 the cost of the Noctilux like the 50/1.5 at less then 1/3 the cost of the 50/1.4 Summilux then they would find a market. The Noctilux has a following that would buy the lens if it was at a lower cost.

But would the ZM be able to compete in the middle against the Nokton 1.1 and the Noctilux? I would totally agree if the nokton didn't exist.

 

[kram]

[/But would the ZM be able to compete in the middle against the Nokton 1.1 and the Noctilux? QUOTE]
Which is why the f1.2 Uber Sonnar is an option. Smaller than the other two, focus a few cm nearer, Sonnar bokeh, minimum distortion, high flare resistance but still good resolution. If fills the gap in the current m mount fast lens options.

 

[Roger Hicks]

[/But would the ZM be able to compete in the middle against the Nokton 1.1 and the Noctilux? QUOTE]
Which is why the f1.2 Uber Sonnar is an option. Smaller than the other two, focus a few cm nearer, Sonnar bokeh, minimum distortion, high flare resistance but still good resolution. If fills the gap in the current m mount fast lens options.

Well, yes, it would if it were possible. But you're asking for a better lens (closer focusing, less distortion, high resolution, more flare resistance) and you want it smaller and you can't 'stretch' a Sonnar (triplet derivative) that far. Or even that way.

I know I sometimes come across as an apologist for the big manufacturers, but what a lot of people miss is that often, they are enthusiasts too. They want perfect and affordable lenses as much as the rest of us, and they are rarely lacking in imagination. They are however subject both to commercial restraints (which is why the new Noctilux costs what it does) and to the laws of physics.

If you ask actual lens designers the question, "Why can't you...?" you will astonishingly often get the answer, "Well, we tried it, but..." That's if it's not, "We can't, because..." I mean, did you know that telecentric designs are MUCH harder to correct for chromatic aberration?

"Much harder" means bigger and heavier and more expensive, and it tells you something when you consider that German-built Zeiss lenses for the ZI are big and heavy and comparable in price with Leica lenses. That's what it costs to make the best possible lenses in small numbers, both in the financial sense and in the sense of size.

Cheers,

R.

 

[Sonnar Brian]

You just can't push a Sonnar to F1.2 and faster and get a pleasing image.

So- the Voigtlander Nokton at ~$1,000 sets the bar. The difference between F1.1, F1, and F0.95 is not much- but adds a lot to the cost.

A highly corrected 50/1.2 to take the place of the Konica Hexanon? Again- has to compete with the $1,000 Nokton. I think Zeiss has it right with the 50/1.5 Sonnar priced about the same as the Nokton. "Look" and compact size over speed.