Canon LTM Canon LTM 50mm 1.5 "Sonnar" Photos Please!

Canon M39 M39 screw mount bodies/lenses
On expired Tri-X 400:

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I've read internet posts for some time about "xyz lens is optimized for close up" or "abc lens is optimized for wide open" or "...for F4..." etc. I don't believe it. Lens designers want their lenses to be optimal for everything.

The faster you try to design a lens, like a sonnar, the harder it is to have good resolution with few aberrations. Perhaps there are a few tradeoffs, and one design factor makes them a little better wide open, but not so good a few stops down. Maybe, but almost all designs are better stopped down. And they weren't designing for esoteric modern phrases like "bokeh" and "drawing rendition." They sat down and said, "let's make a Sonnar type lens at F1.5 with as few aberrations as we can....maybe we can tweak the Zeiss design a little." Then they did it.

Canon made their 50/1.5 based on their determinations for the above, and manufactured all lenses, with tight quality control and checking to that design. How would someone now, 50 years later, change that and "optimize a Canon sonnar for F1.5?" It's a set lens design, it was optimized in 1952.
 
Usually when people talk about optimizing a lens now, they mean making the focus accurate at one fstop and less accurate at others by moving either changing the shims (moving the full optics module closer or further from the plane) or by changing the distance between the optics (inserting a shim).

Usually that comes up with sonnars as the design has focus shift. Some people prefer the rangefinder to be correct at 1.5 at the cost of it being less accurate stopped down (often compromising around f2.8-4 as beyond that the depth of field makes up for the different).

At f/1.4, the Nikkor 50mm ltm lens is sharp and contrasty up close but flares significantly at distance. Stopped down slightly, its great across the range. Given the 1.4 performance, I think its fair to say that they prioritized near focus image quality over far focus.
 
If there is one thing this thread shows it is that Sonnar glass really excels for portraits. I don't know what it is but to me the portraits all look so much nicer. Old lens enthusiasts used to talk about a good lens having a "roundness" to the image or about image "plasticity". I think its this look they refer to. Sharp and yet somehow with a touch of softness as the sharp part of the image fades into out of focus.
 
Brian Legge said:
Usually when people talk about optimizing a lens now, they mean making the focus accurate at one fstop and less accurate at others by moving either changing the shims (moving the full optics module closer or further from the plane) or by changing the distance between the optics (inserting a shim).

Usually that comes up with sonnars as the design has focus shift. Some people prefer the rangefinder to be correct at 1.5 at the cost of it being less accurate stopped down (often compromising around f2.8-4 as beyond that the depth of field makes up for the different).

At f/1.4, the Nikkor 50mm ltm lens is sharp and contrasty up close but flares significantly at distance. Stopped down slightly, its great across the range. Given the 1.4 performance, I think its fair to say that they prioritized near focus image quality over far focus.
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You had me agreeing until the last paragraph. The first part you seem to be saying the focus of a sonnar is not linear. But the rangefinder coupling mechanism is, so you may have to shim the lens to make the focus "most accurate" at either close, or infinity. Sure, I'll buy that.

But your last para about a Nikkor being "sharp and contrasty up close" is wrong. There's no "flaring at distance." At F1.4, it has spherical aberration. That is classic "softness", not really flare (loss of contrast due to glass-air interfaces and light bouncing around inside the barrel). Close, far, and middle, it doesn't matter where you focus, wide open it's soft. when you stop down to almost F2.0, the SA clears up - close, far, and middle. Same as any lens.
 
FUJINON said:
Reading this thread has made me think that I should get one of my two Canon 50mm f1.5's optimized for wide open - close up
and leave the other as it left the factory (optimized at f4).
Or should I leave both Canon f1.5's as they are and get a Nikkor 50mm f1.4 to use open wide and close up.
If I did optimize one of the Canon f1.5's for f1.5 would it produce results similar to the Nikkor 50mm f1.4 or would the Nikkor still
have the edge wide open?.
Your thoughts on this matter would be of interest.
Many thanks.
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Where will you get an existing Canon lens "optimized?" How will they do it? Are they going to delaminate the lens, regrind the surfaces to some, as yet undefined, curves, then re cement them? Maybe use a new type of glass for a different refractive index? Remount them in a some, as yet undefined, new barrel? Asking the same question over will get my same answer:

goamules said:
...The faster you try to design a lens, like a sonnar, the harder it is to have good resolution with few aberrations...almost all designs are better stopped down.

Canon made their 50/1.5 based on their determinations for the above, and manufactured all lenses, with tight quality control and checking to that design. How would someone now, 50 years later, change that and "optimize a Canon sonnar for F1.5?" It's a set lens design, it was optimized in 1952.
Click to expand...
 
FUJINON said:
Reading this thread has made me think that I should get one of my two Canon 50mm f1.5's optimized for wide open - close up
and leave the other as it left the factory (optimized at f4).
Click to expand...

You may also consider getting a cheap LTM body (FSU or whatever you want to invest in having 135 film close-ups at F/1.5) and adjusting its rangefinder to match with your lens at this aperture. You avoid the risks of disassembling the lens if doing so.

Or you may want to try your lenses with some digital mirrorless camera that can do live view focusing. You can learn the focus shift of your lenses by focusing on the same subject at different apertures and seeing how much the scale position changes.
 
FUJINON said:
...My repairer Malcolm Taylor in the U.K.is fully equipped to do all lens work and he can perform his "magic" with most optics and does superb work on Leica,Canon and Nikon cameras and optics for worldwide clients.
I will then have a Canon f1.5 factory optimized for f4 for general photography and the second Canon f1.5 optimized for f1.5 when I require to use it close up and at full aperture (eg. portraiture)
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Knock yourself out. I wouldn't let anyone crack open my perfect lenses and change them in any way.
 
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My 1957 Oval Window Volkswagen named "Blauchen" (means small and blue, in German) shot with my 1955 Canon f1.5/50mm lens *wide open* at f1.5 and 500 or 1000/sec ? -ISO/160 - Leica M8 - Late afternoon light - With only minimal photo color channeling in PS2 - The Black and White photo was shot *in camera* not PS.

Enjoy!

Tom
 
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