squirrel$$$bandit
Veteran
My question is, is there such a thing? It seems that most of the lenses we really like are variations on classic designs--Tessar, double Gauss, Sonnar, etc.--and most innovations in recent years have come from refinements in materials and manufacturing, rather than drastic changes in formula.
When you get down to it, are there simply a limited number of reasonable ways to get light down a tube? Or are there new ideas, that would result in different kinds of images, yet to be discovered?
When you get down to it, are there simply a limited number of reasonable ways to get light down a tube? Or are there new ideas, that would result in different kinds of images, yet to be discovered?
ferider
Veteran
Even today, new designs come up and continue to exist in copies, etc., in particular for wide angles. See for example "The Development of the Konica M-HEXANON 35mm F2.0.", by K. Mutsuhito & K. Yukio, 2001. Used and modified for the 35/1.7 Ultron (my guess).
We like to forget it, but design of 35mm consumer optics is much easier than and learns from ongoing research for lenses with much more sophisticated specs, for instance stepper optics for semiconductor manufacturing (Nikon, Canon and Zeiss make those, among others).
We like to forget it, but design of 35mm consumer optics is much easier than and learns from ongoing research for lenses with much more sophisticated specs, for instance stepper optics for semiconductor manufacturing (Nikon, Canon and Zeiss make those, among others).
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Roger Hicks
Veteran
Variable refractive indices within an element. Diffractive elements. They'll do for a start.
Besides, a modern car is 'only' an 1890s Benz. Ultimately, almost all modern lenses are of a very few kinds: usually either symmetrical or Cooke Triplet derivatives, with or without negative lenses or groups behind or in front of the image forming group (telephoto and Retrofocus). Even zooms can be traced back to this, if you try hard enough. Classic Sonnars are Cooke triplets (3 group) with two or three of the single lenses replaced by (usually) 2-glass or 3-glass groups, but as far as I recall today's C-Sonnar 1,5/50 is actually a 4-group with one of the elements split.
Cheers,
R.
Besides, a modern car is 'only' an 1890s Benz. Ultimately, almost all modern lenses are of a very few kinds: usually either symmetrical or Cooke Triplet derivatives, with or without negative lenses or groups behind or in front of the image forming group (telephoto and Retrofocus). Even zooms can be traced back to this, if you try hard enough. Classic Sonnars are Cooke triplets (3 group) with two or three of the single lenses replaced by (usually) 2-glass or 3-glass groups, but as far as I recall today's C-Sonnar 1,5/50 is actually a 4-group with one of the elements split.
Cheers,
R.
squirrel$$$bandit
Veteran
Is there an English version of this document anywhere online? Or through my college library?
ferider
Veteran
Would love to see this derivation for the CV 12/5.6 or 35/1.2. Lens diagrams can be found here http://cameraquest.com/voigtlen.htm.
Only seen the Japanese version, MS. But check out the cancave (spell?) front element.
ampguy
Veteran
Nikon has 2 lenses with a Defocus Control for adjusting the amount of SA in the lens. Canon has a soft focus feature in some lens, not sure what the latter is doing.
Roland - do you have a link for that article in English? I have a Japanese version with poor google translation. Thanks!
Roland - do you have a link for that article in English? I have a Japanese version with poor google translation. Thanks!
Roger Hicks
Veteran
Would love to see this derivation for the CV 12/5.6 or 35/1.2. Lens diagrams can be found here http://cameraquest.com/voigtlen.htm.
It would be a tedious and ultimately pointless exercise, but all you have to do is go through lens designs to see something that looks (a bit) like the 12/5.6, but more symmetrical; then one that looks (a bit)... etc.
Besides, symmetrical derivative doesn't mean 'wholly symmetrical' amy more than 'triplet derivative' means 'having only three groups.
Cheers,
R.
ampguy
Veteran
I'd like to see this old design back in a new lens, the Pentax 43/1.9 comes close.
http://www.kenrockwell.com/leica/images/35mm-f14/diagram.jpg
http://www.kenrockwell.com/leica/images/35mm-f14/diagram.jpg
naql
Established
That looks a lot like the CV 40mm 1.4:
http://www.voigtlaender.de/cms/voigtlaender/voigtlaender_cms.nsf/id/pa_asan6m4dvt.html
ampguy
Veteran
ferider
Veteran
A modified Planar, Ted, with additional element behind the aperture for speed/against vignetting. Also called "wide-angle Planar". Beside 35 Summilux and Summicron v4 found in many other lenses today.
Roland.
ampguy
Veteran
Thanks Roland, lots of great info. for me to study there.
squirrel$$$bandit
Veteran
I think the Pentax 43 is the closest thing in Leica mount to the Contax G 45/2. I did a very rough wide-open comparison here, using the SLR version of the 43.
Chriscrawfordphoto
Real Men Shoot Film.
Most of the new work in lens design is in very wide lenses, super telephotos, and zooms. Lenses in the close to normal primes ranges (24-135mm) are all pretty standardized designs. There's been work on some of the wideangles in that range to make them faster than the standard f2.8 and f2 max apertures, like the new Nikon 24/1.4 but zooms are the main thing now, not primes.
ampguy
Veteran
John, both images look good. I've never used the Contax 45 lens.
I think there may be a possibility that the SLR and LTM lenses are different, in more ways than the mounts and AF of the SLR, but both produce very nice images.
I think there may be a possibility that the SLR and LTM lenses are different, in more ways than the mounts and AF of the SLR, but both produce very nice images.
squirrel$$$bandit
Veteran
I believe they are identical, the SLR and RF ones. The SLR is practically a pancake--the RF, if I'm not mistaken, has a fair amount of air behind the rear element? In any event, it's a killer lens. I wouldn't mind having the LTM one someday.
GRIN lenses. We've used them in Fiber Optic systems for a long time now. I think they were used in a Canon Zoom? I forget, should google it.
I have one lens based on Tangent rather than Sine, more difficult to manufacture. It was used in an Optical Computer built in the 1980s and preserved the phase of the image as it passed through the optics. All the light rays that entered the lens at the same time formed the image at the sensor. It was used to process and identify images all-optically. The optic was $40K.
The biggest boon to modern optics is molded aspherics. It allows optical designers to perform more corrections with less-complicated optics than ever before.
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ampguy
Veteran
which SLR version?
which SLR version?
The SLR versions (and there are many) are "Limited" and not "Special"
though the optics design may be similar, I guess I'd want to know which Pentax 43/1.9 SLR version you are comparing with - K mount? M42? leaded glass? non leaded glass? Does it go to F22? the Special goes to F16.
Aperture blades? This one is interesting. The brochure states 9, but mine has 8 (like the SLRs I think??):
http://www.pentax.jp/japan//imaging/catalog/pdf/l43_special.pdf
Limited 43/1.9 focuses to .45m, Special just under 1m, the "air gap" is equivalent to any good lens, like the Summilux-M, for example, and air gaps are good for digital sensors.
But the biggest difference I've seen is the rendering of certain types of lines.
Maybe an lens expert can weigh in on here, can you just take a pancake SLR lens assembly, remove the AF doodads, drop on some manual focus assembly with RF cams and all in a lengthened tube and have the same lens on an RF and SLR?
The closest I've seen have been like adapters for Contax or Nikon SLR lenses to M-mount, which all used scale focus, or re-designed lens like the 105/2.5 ltm and then the ~20 versions of F mounts later on.
which SLR version?
The SLR versions (and there are many) are "Limited" and not "Special"
though the optics design may be similar, I guess I'd want to know which Pentax 43/1.9 SLR version you are comparing with - K mount? M42? leaded glass? non leaded glass? Does it go to F22? the Special goes to F16.
Aperture blades? This one is interesting. The brochure states 9, but mine has 8 (like the SLRs I think??):
http://www.pentax.jp/japan//imaging/catalog/pdf/l43_special.pdf
Limited 43/1.9 focuses to .45m, Special just under 1m, the "air gap" is equivalent to any good lens, like the Summilux-M, for example, and air gaps are good for digital sensors.
But the biggest difference I've seen is the rendering of certain types of lines.
Maybe an lens expert can weigh in on here, can you just take a pancake SLR lens assembly, remove the AF doodads, drop on some manual focus assembly with RF cams and all in a lengthened tube and have the same lens on an RF and SLR?
The closest I've seen have been like adapters for Contax or Nikon SLR lenses to M-mount, which all used scale focus, or re-designed lens like the 105/2.5 ltm and then the ~20 versions of F mounts later on.
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squirrel$$$bandit
Veteran
There is only one Pentax 43/1.9, an autofocus K-mount lens...it is indeed a Limited. According to the bartender's site, it contains the same optics as the LTM lens.
Roger Hicks
Veteran
Dear Brian,
Absolutely. Well, that and anomalous dispersion glass. That's what I meant by my post that a modern motor-car is 'only' a 19th century Benz. Or for that matter, a Prius is a 1900 Lohner-Porsche (though I don't think the Lohner-Porsche had as many problems...)
A lot of people fail to appreciate exactly how technology evolves.
Cheers,
R.