goamules
Well-known
He's just trying to correct wrong information about optics. Spherical Aberration causes "softness". Coma along with Field Curvature cause swirl. All three are worse the faster the lens, and diminish when stopped down.
mdarnton
Well-known
I really hadn't paid much attention to these issues until a couple of years ago when I got a 5x7 camera and started hanging around large format stuff and people, when I was introduced to a whole new world of old lenses. There's a big sector of interest there in soft focus, and the lenses that do that, and I learned a lot about it that explained some things in this discussion to me.
The early SF lenses depended on both chromatic and spherical aberration. The interesting thing to me was that these result in two things: first, there's a sense of wider depth of field because with light rays of different colors or from different places on the lens focusing at different distances to the film the effect is that each specific distance in the DOF range has both out of and in focus components. That is, each detail you might look at is imaged partly in focus and partly out, over a wider range, rather than at just one specific distance. This is where the slight halo around highlights comes from, as a blurry out-of-focus bleed and that halo is the second effect on top of DOF. PeterM's shot of the singer on the first page is a really nice faking of the effect.
The other thing to know is that these effects are large aperture effects---stop down any lens and they go away. LF portraitists used this to vary the SF effect according to subject.
As many noted above, with improved computer design, many of these effects gradually disappeared and lenses became increasingly clinically sharp at wider and wider openings. Coming from 35mm, I had always thought that old lenses' lack of sharpness at wide openings was a defect, but now I understand it differently, as a way of adding a certain type of diffusion to the situation, as so many people above have noticed and prefer! So I'm slow to the party here. The other component of it is age and fogging, and in following up this topic more actively, I've found people complaining that when they send their old lenses in for cleaning the glow goes away. :-(
Anyway, modern lenses gradually "perfected" and all of this went away. In the large format world I've personally centered my buying on Tessar types, which have a special (what Leica people would call) glow when used wider, without being unsharp.
By the way, if you want to see some people who are handling the extreme of this effect really nicely, go check the Monocle (single element lens) Flickr group!
The early SF lenses depended on both chromatic and spherical aberration. The interesting thing to me was that these result in two things: first, there's a sense of wider depth of field because with light rays of different colors or from different places on the lens focusing at different distances to the film the effect is that each specific distance in the DOF range has both out of and in focus components. That is, each detail you might look at is imaged partly in focus and partly out, over a wider range, rather than at just one specific distance. This is where the slight halo around highlights comes from, as a blurry out-of-focus bleed and that halo is the second effect on top of DOF. PeterM's shot of the singer on the first page is a really nice faking of the effect.
The other thing to know is that these effects are large aperture effects---stop down any lens and they go away. LF portraitists used this to vary the SF effect according to subject.
As many noted above, with improved computer design, many of these effects gradually disappeared and lenses became increasingly clinically sharp at wider and wider openings. Coming from 35mm, I had always thought that old lenses' lack of sharpness at wide openings was a defect, but now I understand it differently, as a way of adding a certain type of diffusion to the situation, as so many people above have noticed and prefer! So I'm slow to the party here. The other component of it is age and fogging, and in following up this topic more actively, I've found people complaining that when they send their old lenses in for cleaning the glow goes away. :-(
Anyway, modern lenses gradually "perfected" and all of this went away. In the large format world I've personally centered my buying on Tessar types, which have a special (what Leica people would call) glow when used wider, without being unsharp.
By the way, if you want to see some people who are handling the extreme of this effect really nicely, go check the Monocle (single element lens) Flickr group!
Ranchu
Veteran
Word salad, man. It's just a bunch of declarations tacked together with vague semantic insinuations. I'm not buying it, anyway. I mean, everybody already knows fewer elements tends to have better 3D, you need to explain why one tessar type has 3d and one doesn't, if you're going to try to claim everyone else is 'wrong'. Right?
Ranchu
Veteran
You're currently lacking the credibility to make me think it's worth it.
Michael Markey
Veteran
I`m going to have to use that ignore button after all ...
Ranchu
Veteran
I tried. It doesn't work if you're not logged in!
enasniearth
Well-known
Lens characteristics
Lens characteristics
Any postwar coated lens will have more contrast and more flare resistance
Than earlier uncoated prewar lenses .
I shoot with lenses from the 1950's and 1960's
For most purposes any coated lens from one of the major players back then
Leitz ,Zeiss,nippon kogaku or canon will do a very nice job.
The faster the lens in maximum aperature , well there is where most
Differences are noticed ,
Take a bunch of lenses shoot f8 at a fast shutter speed and most differences disappear .
I have a nikon s2 with a 5cm f1.4 and 2.8cm f3.5
They do it for me ,
Sure there are probably better lenses but by how much ?
It's most important to get used to your lenses and your chosen film .
You can then provide consistent results and concentrat on the image in the finder.
It's what's inside you , what you see and how you record it that's important .
Lens characteristics
Any postwar coated lens will have more contrast and more flare resistance
Than earlier uncoated prewar lenses .
I shoot with lenses from the 1950's and 1960's
For most purposes any coated lens from one of the major players back then
Leitz ,Zeiss,nippon kogaku or canon will do a very nice job.
The faster the lens in maximum aperature , well there is where most
Differences are noticed ,
Take a bunch of lenses shoot f8 at a fast shutter speed and most differences disappear .
I have a nikon s2 with a 5cm f1.4 and 2.8cm f3.5
They do it for me ,
Sure there are probably better lenses but by how much ?
It's most important to get used to your lenses and your chosen film .
You can then provide consistent results and concentrat on the image in the finder.
It's what's inside you , what you see and how you record it that's important .
Ranchu
Veteran
The premise is , you should be helping the OP answer his question. But you contribute 0% in this regard. Please explain how you are being of any USE?
I appreciate that you're trying to help the OP. I'm just not making any sense of what you're trying to communicate, throwing buzzwords at me and saying THAT! THAT! isn't helpful, and it seems to me that you're not actually trying to communicate, only trying to flap around. Particularly when you pretend not to hear when I asked about the two tessar types. I also think 'dielectric capacitor' is redundant, in an obfuscatory sense.
Cheers!