Black and white imaging brings to light different lens characteristics. These are not wholly different to colour lens characteristics, but sometimes the emphasis of these characteristics changes.
Since leaving the camera industry, I have been able to shrink my world down from shelves of expensive lenses, back to just what I know and trust. My humble 25 and 45mm lenses, which were assuming near cheap give-away status are again precious and appreciated friends. Already the self inflicted therapy is showing benefits.
The primary characteristics that mono will effect are contrast, micro contrast, brilliance and Bokeh*. Each of my lenses are pretty well known to me now, but not in a black and white context, where I suspect the subtle differences will out, but maybe not as I expect.
The 17mm f1.8
This lens has always exhibited high micro contrast and gentle colour, that I suspect will manifest as nice, film like roll off of tones and pleasant highlights. This will likely match a Tri-X** film feel, which I have heard referred to as a “cold” or fast roll-off film . This type of film rarely showed much “glow” or brilliance, but rather emphasised deep and gritty textures and expanded mid tones. This characteristic suits the lenses expanded, slow transition Bokeh, which also emphasises texture.
Not strong on shiny, but good on tone.
The 25mm F1.8
This has always shown the opposite characteristics to the 17mm. This one may be the Ilford FP 4*** film look alike, as it tends towards brilliant and generally more contrasty. Fantastic for reflected light, metallic and water subjects it should produce strong, deep blacks, glowing whites and compressed mid tones. FP style films was not a favourite back in the day, but I used it when it’s unique characteristics were ideal. Bokeh with this one is pleasant in the modern sense, but a little over the top for my tastes, going to smooth mush very quickly (I know I am off trend here, but trends are just that).
Lots of abstract miss-cues work with lenses like this as they render out of focus areas smoothly and add brilliance to blurred colours.
The 45mm f1.8
This one falls somewhere in between the 17 and 25. It shows brilliance when needed, but also offers haunting subtlety in mid tones especially and when light is difficult. Like the 25, it has forgiving, beautiful Bokeh, but more highlight control and like the 17mm it has tons of character. The slight flattening effect is natural, that is to say not too flattening (see below), which adds to the very natural feel the lens offers. I think this one will perform like XP2 film, which is the C41 colour process mono film, that has the unique ability to change character as needed.
These harmonious characteristics I hope will make the 45mm the work horse of the pack.
The 75mm f1.8
Rounding out the 1.8’s is the powerful 75mm. It is by far the most opinionated of all of my lenses, flattening and separating subjects with little doubt to it’s intent. This is a lens with a task to perform and that it does with aplomb. It can be a bit of a one trick pony, so should be used sparingly or the near perfect look it has can become boringly predictable, like perfect days in the tropics. If I think of the beautiful tonality of Pan F 50, as a versatile ISO 400 film, I have maybe got a handle on this one.
This lens is so consistently good it has defied categorisation since I have tried. It shares both strong micro detail and tons of rich glow. It is sharp wide open and the colour is beautiful. The only issue it has, and the main reason I have avoided the f1.2 lenses, is it is a little too perfect, lacking character and a little unpredictability, that makes life fun. It is, and will always be, my “big look” lens.
Even though it provides a decent candid working distance, you still need to be a little careful.
*Bokeh, meaning the in to out of focus transitions of the entire image at all focussing distances and with any aperture, not just wide open and in your face.
**Tri X or the “cold” S-Curve films included (from memory), Agfa APX, Ilford Pan F, Delta and HP5 films. These films “round off” blacks and whites, strengthening mid tones. These films were often referred to as “gritty”.
***The “Hot” or steep S-Curve films included (again from memory) Ilford FP 4, XP2, Kodak T Max and Fuji Neopan films. These films tend to go into deep black and brilliant whites very quickly at the expense of mid tone range. Some even had limiters built in so they would not blow out completely. They tended to have a smooth tonal look.