Ah, this old thread is back to haunt us, it will not be ignored...
Thinking in terms of specific equipment for black and white sounds ridiculous to me. I'd be surprised to hear from any photographer who reaches for a certain lens when considering a black and white composition.
Be surprised! And when you've picked yourself up off the floor you will realise that you were right all along...
When shooting *film* there were lenses that *worked with B&W* and showed a far poorer performance with colour. As @stevo23 states there are aberrations due to colour so with old ortho-chromatic film, or pan-chromatic in conjunction with a yellow filter, you remove a lot of this. So *good for B&W* generally meant *useless with colour*...
But I'm not supporting the idea that a lens with high CA or LoCA is good for BW - on the contrary. BW doesn't hide fringing, it just turns it monochromatic, but it still appears as a loss of perceived sharpness.
Ortho-chromatic silver halide film is only sensitive to the blue end of the spectrum and so even if the lens fails to focus the entire spectrum of visible light in one spot at the edges of the image then it becomes less of a concern if the film is only sensitive to a narrower band of wavelengths. This is the same when using stronger filters for B&W film, if you only allow to pass a part of the visible spectrum through the lens then you reduce aberration due to the different refractive indices of different wavelengths.
But there are also older lenses that have remarkable properties when combined with B&W *film*... I reach for them when using film, because of the way the film responds. With digital I wouldn't dream of using them, useless...
You're associating BW with film somehow - that doesn't make any sense for at least the past 70 years.
It is inherent in the nature of film that it has a threshold, or a level of light that must be absorbed before a reaction takes place and a latent image is recorded (the film speed). It is also in the nature of a lot of very old un-coated optics used exclusively with B&W that they had a level of flare that often sat below the threshold of the film. This basically had the effect of *pre-sensitising* the film as in it applied a universal level of light (energy) across the whole film. The end result is that although you had an increased level of fog on the film the details in the deep shadow when combined with this flare actually had enough light energy to create a reaction in the film and so record some detail, where without the flare they were below the threshold (sensitivity being a log scale this had no effect on the highlights). I have one such lens from around 1910 and though remarkable when used with care of B&W it is useless with colour because of the way the silver halide/dye layers work with the orange filter layer.
As I explained, the language that is used to describe a lens as a *good B&W* lens relates to the film days. You can't just view things from a current understanding of digital and apply it to film, film simply doesn't work in the same way.
I still use these lenses and techniques with modern B&W film so your a little more recent than your *70 years* estimate...
[ATTACH alt="FP4 Plus, 5"x 4" sheet film. With standard development keeping the detail outside the window placed the shadow values on and below the threshold of the film, pretty much pure black. At f22 the indicated exposure was 2 seconds so allowing for reciprocity failure a 4 second exposure was indicated just to keep the shadows pretty much pure black, but would've pushed the highlights (the level of light was above reciprocity and so no failure) up another stop and so forced a *stand* development to maintain some highlight detail, and subsequent loss of contrast. What I was after was the impression of light and maintaining the highlights against shadow. So I used my 1910 Tessar at 2 seconds with a yellow filter because in cases like this the level of flare from the window means I can ignore reciprocity and just expose for the highlights and the shadows will still record with some detail. In the scan and finished print I bring the shadows down and the finished is below. It is what I call a *good B&W lens* because it's properties suit B&W film but are detrimental to both colour film and digital as to render it quite useless."]2323595[/ATTACH]
FP4 Plus, 5"x 4" sheet film. With standard development keeping the detail outside the window placed the shadow values on and below the threshold of the film, pretty much pure black. At f22 the indicated exposure was 2 seconds so allowing for reciprocity failure a 4 second exposure was indicated just to keep the shadows pretty much pure black, but would've pushed the highlights (the level of light was above reciprocity and so no failure) up another stop and so forced a *stand* development to maintain some highlight detail, and subsequent loss of contrast. What I was after was the impression of light and maintaining the highlights against shadow. So I used my 1910 Tessar at 2 seconds with a yellow filter because in cases like this the level of flare from the window means I can ignore reciprocity and just expose for the highlights and the shadows will still record with some detail. In the scan and finished print I bring the shadows down and the finished is below. It is what I call a *good B&W lens* because it's properties suit B&W film but are detrimental to both colour film and digital as to render it quite useless.
I do actually know what I'm talking about in this instance.
;-) ;-) ;-) ;-)
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https://timtuckerphoto.smugmug.com/Scotland-1/
Thank you for the suggestion.
