Simple lenses and choppy bokeh

Remember the film title Things to do in Denver when you’re dead? Well this is things to do in the house when you are trying to not be. In the house I mean, although not being dead is important too.

Despite all the therapy and support, in times of idleness one’s fancy can turn to things of bokeh. Or the unimportant bit, as we used to call it. That’s when you realise you have several lenses of the same focal length but different construction. And you wonder why, and what the difference is between them. And if the really clever or expensive lens is actually better than the cheap one. And what better means. And if this means you need to buy more lenses. Or find better backgrounds.

So you find the adapter that mounts your cheapo nasty analogue lenses on your digital camera. This takes two hours and uncovers more interesting old lenses. But you only have one version of each of them. So when it gets dark and eBay closes for the night you come back to the plan. One focal length, one aperture, one scene: the ultimate shoot-off. But is it fair to compare a lens that can do f1.2 with a lens that has a maximum aperture of f3.5? Do you compare them all at the same aperture or at their widest? More time passes.

After a few more beers you decide that the reason you started this (and it is totally your fault) is to see what the backgrounds looked like. Kind of an aide memoire of which lens to use to get which effect. So it’s fully open aperture on all lenses to get the best of their aberrations. But to use a scene where the point of focus is close, so that we get lots of the fuzzy. And we reassure ourselves that we haven’t gone all Photography With Classic Lenses and that we still have a sliver of pride and self respect. And then we laugh and drink more beer.

So – big question: what sort of fuzzy does it for you?

Me? I’m a smooth guy. I like the out of focus areas to just look less sharp. I want my background to be background. Smooth tones. No magic circles or swirly. Nothing that looks like the subject is stood in a whirlwind or bubblebath. The only reason to use the weirder lenses might be that the pattern in the background somehow adds to the shot. Otherwise it’s the background. But that justifies the other lenses, right?

Now, some of the theory to this is that the rendering of the background is affected by how well-corrected the lens is for spherical aberations. And a simple magnifying-glass lens gets better corrected for other aberations by adding more elements to the design along with different types of glass. It’s fairly easy to make a reasonable lens at small aperture sizes, but the wider you want the lens to be the more clever the design has to be, which often involves yet more bits of glass. So the argument is that a simple lens ought to have more textured out of focus areas than a more complex and better-corrected lens.

So where does that leave me on a Sunday afternoon? I have, in the same focal length, lenses with from 3 to 7 elements. I have lenses that span the all famous design formulae. To be honest, I have a sufficiency of lenses. And I have time.

So, the simplest lens is no lens. But I have no pinhole cameras at the moment so this is out. Same with a simple meniscus (but been there, done that on medium format) or a doublet. Got a triplet though.

So I’ve got:

• Triplet – a Meyer-Optik Goerlitz Domiplan 50mm F2.8.
• Four elements in three groups (Tessar) – an Industar 50-2 50mm f3.5.
• 6 elements in 4 groups and probably a Planar design – Rikenon 50mm f1.7.
• 6 elements in 4 groups, but a Biotar design – Helios 44 58mm F2.
• 7 elements in 6 groups, probably a version of the Planar – an Auto Yashinon 55mm F1.2.

This is what I had to hand – I am not spending time on eBay looking for a five element lens.

Now, everyone buys the Domiplan lens because it does bubble bokeh: out of focus highlights turn into circles. With only three lens elements, it doesn’t really correct for much at all.

At the other extreme, the Yashinon has seven elements, not so much to make the lens sharper but to manage the aberations in a design that is more than two stops wider than the Domiplan. Somewhere in the middle might be the sweet spot of fast enough and smooth enough – the Goldilocks lens.

My first idea was to shoot them with a nearby lamp as my subject and a window behind to give me some highlights. That didn’t really work, as they all looked quite similar. The only one that stood out was the Yashinon. This was because the design that was pushed to work with a front element almost two inches in diameter caused some crescent-shaped highlights away from the centreline of the lens. This is the downside of pushing a lens design this far.

So instead of dithering indoors, I persuaded Wilson‘s cousin Gilbert to stand in as my model in the garden. He’s a rugged fellow with plenty of skin texture, so ideal.

The background is quite busy and showing bubble highlights

Smoother background. This is a lens I like.

Nice – I’ve had this lens a long time and I can see why.

The background is getting a little swirly.

What background? Was it foggy?

So, what do I think?

Well, one thing was that some of the lenses had noticeable field curvature. In each case I focused on the B in the centre of the lens than reframed the shot. In some, like the Domiplan, the sharpest point has moved nearer the camera. Something to be aware of – I can’t just reframe some of these lenses if I use them wide-open.

The Domiplan is a cheap lens that does the bubble trick on background highlights. It’s OK for that but it can make the background look quite busy.

The Industar 50-2 is great – I really like this lens. It’s tiny and it renders backgrounds smoothly. A bit of a pain to use though, as the aperture is manual.

The Ricoh/ Rikenon is the standard lens that came on my first SLR camera. It does a good job and doesn’t intrude. It works on my film kit and on the digital and gets the highest praise: it just works.

The Helios is a real cult lens because it can make backgrounds look swirly. It’s slow to use, as mine is one of the older ones with a preset aperture. Given the choice I would usually take the Industar, because it is so much smaller and lighter than the Helios.

The Yashinon is bonkers. It does crescent-shaped highlights, it does completely fogged backgrounds, it can see in the dark. On digital it also gives coloured fringes and a bit of a glow to things – see the shots above. Unless you want to shoot at F1.2 all the time it needs to be used on a proper M42 mount, so I use it for film work.

My conclusion? The Domiplan and the Helios are special effects lenses. The Industar is a superb pancake lens with good rendering. The Ricoh is a rock-solid standard. The Yashinon is there for when you really do need to separate the background or to take pictures in the dark. And your mileage may vary.

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