Classic lenses

Classic seems to mean ‘not made any more’. I used to be interested in classic motorcycles, but classic came to mean extinct rather than good and some complete dirtburgers were given a rebore and a coat of paint and became “classic”. Never mind that the refurb would have cost more than the bike was ever worth or that people who owned one at the time were only too happy to trade it for a Honda. And the result of all the effort is that the proud owner gets to take it to shows on a trailer and have people tell him that the shade of paint is wrong for that year.

I too rode a classic motorcycle, but it had raised compression, a twin-plug head and a chain oiler, and I rode it to work. Oh dear, I’m getting into reverse willy-waving again. Let’s get back to lenses.

So – a classic lens is one that you can no longer buy new. I did ask and was firmly told that a classic lens is also a fixed focal length: zoom lenses are not classic. From what I can see, the most prized feature of a classic lens is the way it renders out of focus areas, particularly highlights. Remember the mirror lenses that were, for a while, the easiest way for mortals to afford a long lens? There were a load of 500mm f8 catadioptrics to choose from, but their distinguishing feature was the way they rendered out of focus highlights as circles. Pretty much a one-trick pony: once you had seen a picture full of bubbles you probably sold the lens and went back to refraction as your favoured method for bending light. And now people pay big wonga for Meyer Goerlitz lenses that have sufficient aberrations to recreate the effect. Want to do it for cheap? Try a longish lens with a clear filter and a disk of black paper or tape in the middle of the filter. If there wasn’t a Cokin filter that did this I’m sure I could sell you a bubble bokehlicious®️fuzzy duck filter.

A few minutes work with a marker pen and the first Fuzzy Duck filter leaves the production line

Ooh, bokeh balls, yum! The odd texture in them is due to the swirls of the marker pen

So ok, rings is a thing but not the only trick in town. The other things that classic lenses are supposed to be good for is micro-contrast, meaning low contrast as far as I can understand it, and not smoothing-out fine detail (which may be the same thing). But perhaps this only applies to CLASSIC lenses and not just any old bit of second-hand glass. From what I understand, older lenses suffered more with flare and reflections. This could mean that the overall contrast between highlights and shadows was reduced, so kept within the dynamic range of the film. If the lens was a good one and could resolve fine detail, this could be what people call microcontrast. As coatings got better I assume that the overall contrast rendered by the lens increased. It may well be that this exceeded the ability of film to capture it, and the abilities of earlier-generation digital sensors. Digital sensors now beat film on both dynamic range and sensitivity, so I would expect that a modern digital camera with a modern digital-designed lens will render both fine detail and a wide overall contrast. Stick this clever lens on a film camera and you might find it too contrasty. Stick an older film lens on a digital camera and you might find it reduces the overall contrast of the scene, so it needs less post-processing.

There are also some issues with putting older film lenses on digital sensors, in that a digital sensor prefers the light to arrive straight-on, where film doesn’t mind if the rays are oblique. This matters at the edge of the frame, and more in colour than black and white. So some film lenses on some digital cameras produce fuzzy edges or colour fringing.

The main idea seems to be though that older lenses contain magic. They don’t resolve every skin pore, the backgrounds are nicely smooth and not distracting, and the fall-off from sharp to out of focus looks nice. Sensors smaller than the original film size turn old lenses into longer focal lengths (narrower angle of view), so a fairly cheap 50mm film lens can become a very cheap wide-aperture portrait lens. This will throw the background out of focus and isolate the subject better than the zoom lens that came with the camera, and way cheaper than a sharp digital lens of the same size.

But watch what happens with mobile phones and how it will migrate to mainstream cameras. Before long you won’t need to buy a Planar or a Sonnar and deal with fungus or scratches; you will use the kit lens and dial-in your lens effect. The autofocus knows which parts of the image are sharp, so the in-camera computer can add your favourite aberrations back to the fuzzy bits. Pentax released a software developer’s toolkit for their K1 full-frame camera, so this might be where you see it first.

But this idea that old lenses were better than new lenses? Prove it. Technically better, in terms of resolving power, control of flare, sharpness across the image? I doubt it. A more pleasing rendering of the image due to design or manufacturing shortcomings? In the eye of the beholder, but apparently true if you have seen how the prices of some old lenses have risen. Come the revolution though, and I’m hoping the prices drop again as in-camera effects mean that everyone can have a Canon ‘dream‘ lens.

Update
it’s already here.

Author: fupduckphoto

Still wishing I knew what was going on

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