Actually, it isn’t a bad question, and there was a book dedicated on the subject about 35 years ago. (Sorry I don’t remember the book title.) But the fact of the matter is that any comparable lens with the widest possible front element is best, with a solid emphasis on speed. (f:1.0-1.8). The reason is that in B&W you are picking up IR and UV light that translates into visible aspects on the print. (see above notes on red filters.) What that translates to, is that in B&W the lens needs to be as high quality as you can possible afford. IR and UV refraction takes a huge back seat to color, and isn’t as obvious in color as one would think. the reality is that B&W is sensitive on both sides, and has a problem with putting them in focus. (Hence the IR position on older lenses). Anyway, the fact of the matter is that with slower B&W film and slower B&W apertures, ISO's etc, the IR side can actually cause a ghosting effect. (keep in mind this is really high end stuff), but when printed, especially on the old Kodak Metallast paper and the latest equivalent, the IR spectrum can show up. To the trained eye, it does make a difference. But if you’re not interested in perusing that level of B&W snobbery, then stick with pp in Photoshop for now until the manufacturers hit a true B&W system on the digital.