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.

TOMIOKA

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.

Domiplan pair
The background is quite busy and showing bubble highlights
Industar pair
Smoother background. This is a lens I like.
Ricoh pair
Nice – I’ve had this lens a long time and I can see why.
Helios pair
The background is getting a little swirly.
Yashinon pair
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.

Self critique through scanning

Like a lot of people, I’m at home rather than commuting to work at present. I’m lucky in that I can do a lot of my job from home, so I’ve been spending more time than I’m used to sat in my study. Yep, I call it that. We must maintain standards.

Just to the side of my desk is an old PC that runs my scanners. I didn’t take long for me to realise that I could poke a negative carrier along by one notch and hit scan, with no interruption to the day job.

I have rather a backlog of scanning. There were times past when I didn’t have the kit, the free time or the inclination to sit and feed a scanner. But now I have to sit next to one for eight hours a day.

It turns out there is some joy from discovering photos I knew I’d taken but lost track of. There is also some learning to be had in reviewing what I used to take pictures of. I have noticed that in the early days I used to take two shots of the same scene, from the same viewpoint, with the same exposure: basically two identical shots. I was so unsure of my technique that I was giving myself an extra frame in case of scratches, holes or other disasters. Totally unnecessary – I had quickly got past the stage of physically damaging the film by accident. I wish I had used the second frame to vary the exposure instead. How could I be so worried about damaging the film and yet so sure that I had nailed the exposure?

I can also see my photographic history through scanning. There is the black and white when I first started. It was cheaper to buy and I very quickly learned to develop it myself. Then I got a bit up myself and went all quality. There is a long period of slide film with just a few mono negs. I think these must have been the days when slide film was reasonably affordable. Of course, Real Photographers only shot colour slides, never colour negatives, and I so wanted to be good. It did leave me with an abiding love for Agfachrome 50s though. Then I probably realised just how far I had walked away from sociability and started shooting only colour print. I basically became a best friend of TruPrint. Does anyone remember them? You sent them a film in a plastic envelope, they developed and printed it and sent it back with a new film and envelope. It’s like the scene in Brazil with Sam Lowry and the message transport tubes.

Then we go through a digital period with hundreds, probably thousands, of pictures that only exist in my computer, with a few having made it onto the walls. Then the black and white reappears, but edgy and experimental. Or shite and forgotten how to work it. I never really left film photography, but it dropped back to a minor sideline for a while. One thing I do remember is asking for Agfachrome in a photo shop, to be told that it was no longer made (not since 1984 – eek!). I suppose I should be glad that they had even heard of it. A bit of a Fly Fishing moment. [And I have just realised that all the references here are to the 1980s. Not deliberate and certainly not nostalgic.]

But, unlike some, I don’t think I have ever thrown a set of negatives away. Well, not that had any sort of visible image on them. So I am working my way through boxes of badly-labelled slides and negatives. I can only think that, at the time, it was so obvious to me where and when the pictures were taken that I thought labels were superfluous. I admit to having completely forgotten some of the places I have been. Tunisia was one. I recognised the pictures, but the label on the slide box was a puzzle until it came drifting back. Yugoslavia? I definitely remember going, but I had no idea what it looked like or where I had been. And things keep turning up in the pictures that I thought were in completely different countries. A large stately home turns out to be in Ireland and not Northumbria. A decorated column is in Leningrad, not Rome. The camel was not in a zoo.

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But this is not about my focus being much more on the present than the past (a polite phrase for dodgy old memory), or on my former globetrotting (well, stumbling). The pleasure here is looking at the old photos and being mostly very glad I took them. The interesting thing though is how the importance of pictures changes with time. Scenery that was spectacular to be in results in (usually) meaningless pictures with nothing in them. Snapshots of people and places become fascinating. Friends grow old, children grow up, cars become classic. If only hair grew longer and waistlines slimmer.

Fun though. Plus I have discovered some excellent pictures of people that I will use again, especially one of my sister which awaits her next major birthday. The things I shoot have altered a little, probably for the better. There is less of the dull landscape in recent times and more interesting stuff. In the early years I seemed to hose the world with my camera. Since then I have learned (and occasionally practice) that a picture of everything contains nothing, so there is more of the detail or single item that stands for the whole.

75

The other thing I noticed is that, despite what people say about the archival permanence of film, some of my old colour stuff is not holding up very well. It’s probably a good idea to get some of these old negatives and slides scanned as they are showing some odd colour shifts. The slides seem to be in better shape than some of the old colour negatives, although even some recent (2005) colour negative is showing some strong colour casts. All the better to get them scanned then. And what a good time to be doing it, when I’m locked in and getting distinctly Oscar with the wallpaper.

So here I am, like all of us, making a benefit out of a necessity.

Stay safe.

What did you do during the lockdown, daddy?

So, cheerfully, here we sit, hunkered down and hoping to reduce the rate of infection to something the health service can barely cope with. I work in IT, so I could say that I’m used to social distancing. I’ve also spent the early weeks working flat-out to equip the previously desk-bound part of a business with home working tools. It’s going to be interesting in the future when people realise that buildings, commuting, fixed hours and physical presence might be worth less than outputs. I wonder what sort of society we will become?

Anyway, enough of the nascent revolution. What can someone with basic film developing skills do when they are only allowed out for their one hour Boris break each day? Make beer.

A tea urn, a picnic cooler, some jugs and pots and a few ingredients and magic happens. This is not beer from a kit: this is home-built beer. I was lucky that I was given a day’s course in brewing as a gift a couple of years ago. The process itself is quite leisurely, with periods of waiting, so I must admit the entire course got totally canned while we were at it. So last year I bought a year’s worth of ingredients and knocked out a batch every three weeks. This year I bought another bulk load of grains and ingredients without realising that they would arrive shortly before the virus started spreading. So while I may not be stood at the sink inverting a tank, I’m still sloshing water about and measuring ingredients. It also scratches my creative itch – there’s much fun to be had inventing or adapting recipes. I’m not shooting enough film at the moment to be doing much with photography, but I have so far made:

  • Czech lager
  • Old Peculiar
  • An amber IPA
  • A dark IPA
  • A malty pale ale
  • A citrus pale ale

Yes, I do like my IPA, but I’ve also got two lots of porter and a Russian Imperial stout planned.

Beer
Two hobbies in one – a photo of beer

I think my main problem could be, come VC day, that I won’t want to leave the shed. I may not be able to find the shed door, either.

Stay safe everyone.

(Normal service will be resumed next week)

Awkward focus

How do you focus a camera that doesn’t tell you when it’s in focus? That’s really awkward.

If you can learn how to do this trick, there are loads of interesting old cameras that you could use. They can be reasonably cheap too, as people do prefer things you can focus. And yet, you may have heard the pundits talking about magical solutions like zone focussing or hyperfocal distances. What’s a poor boy to do when you thought zones were something to do with exposure and hyperfocals were what old people went to opticians to get?

Focusing a lens means moving it nearer or closer to the film or sensor, so that the light from your chosen subject is brought to the least fuzzy point. There was some stuff about it here. Many lenses have a built-in screw thread so that turning them moves them in and out, without letting light leak past. Other arrangements are possible, but they mostly all do the in and out thing.

Now, our eyes are not perfect and there is a lower limit to the size of things we can see. As you get older, that might be grandchildren. Grant me though, that we can’t see atoms, or even molecules. So when an image is projected onto the film or sensor by a lens, there will be a range of distances where everything appears sharp. If you could look closer, perhaps with a microscope, you could see that that amount that was truly sharp was less than it appeared to the eye. This is why small prints or pictures often look sharper than they are when you make them bigger.

But for practical purposes, there is a range of distances in front of the camera between which stuff looks sharp. This is the depth of field. Where this zone falls and how deep it is depends on several things. Let’s assume for now though that these things are outside your fine control: you can make a basic choice like the camera you are using, but you can’t change the lens on it. Let’s also assume that your camera might have one of the two forms of focusing: controlled and guess, where guess includes fixed and not adjustable. If your camera provides accurate and adjustable focusing and that is what you want, then move along – there is nothing to see here. But there can be good reasons why you might want to use your adjustable camera as though it was not. The main one is often speed of use. Focusing takes time.

So, how do you make best use of either what you are stuck with or what you choose to adopt? According to type is the answer. Guessed focusing comes in three forms: fixed, zone and scale.

Fixed is where there is no adjustment possible. It’s not autofocus – it means the focus of the lens is fixed and you do your best to put the subject in the sharp zone. If you are lucky you may be able to find out from the manual or t’interweb where the focus distance is, or what the depth of field is. I have a fixed-focus camera, and the manual lists the range of sharp(ish) distances for each aperture setting. Without this information you may have to find out, or just live with it. It’s a fair assumption that a fixed-focus camera will be set to somewhere around the distance where you can get an adult in the frame, around mid-length. My own fixed-focus camera is set for about 8 feet. You could leave it at that and just work with it, or use a bit of film in testing. What you need is a long fence or railings that you can shot at an oblique angle so that your picture shows it from close to far. Before you shoot, pace out some distances and mark them with chalk or a stone. Then examine the developed image to see where it is sharp and how far away that is. Then get someone to stand that far away and look at them using the camera, to get an idea of what that distance looks like. Or make a simple version of the card rangefinder. Then shoot everything at the sharp distance.

Fence

Next up is zone focusing. This is where the lens offers a set of symbols for where it will focus. These are usually head and shoulders, group, mountains. Again, you can work with it or do the fence test to get an idea of what each setting does.

Zone focus

In the case of my camera, head and shoulders works out around 1.5 metres or a bit less than 5 feet. Groups fall at around 5 metres/ 15 feet.

Cameras like this can be very quick to use – pick the type of picture you are making, set the symbol for focus and go. Providing the aperture is around f8, you are likely to have enough depth of field to not have to worry.

Scale focusing is like using the symbols, but without the symbols. This is where the lens is marked with real distances, but you have to guess or measure the distance of your subject and adjust the lens accordingly. The lens on the camera above has both a distance scale and symbols. It sounds dreadful – how will you ever be able to estimate the distance acccurately? Use some basic rules:

  • A head and shoulders is around 5 feet, or a bit less.
  • An adult, shot vertical on 35mm with a 50mm lens, just about fills the frame at 10 feet (3m).
  • A group will be around 15 feet, or 5m.

Then use a reasonably small aperture like f8 and it will mostly work. If you are picky or nervous, make yourself a card rangefinder. It will easily fit in the camera case or your wallet.

You can even use a ‘proper’ camera with scale focusing. The street photographers do this for speed. You need to have a lens that has depth of field marking on it.

DoF

If I set this lens to f8, then everything between 2.5 and about 5m will be sharp. If that’s the most likely distance for stuff I want to take pictures of, I can set the lens and aperture and use the camera like a point and shoot. It would let me do slightly wide head and shoulders shots through to slightly tight groups without having to adjust a thing. This is what news photographers used to do, to give them the reaction time they might need to get the decisive moment (as legend would have it).

Then we come to the secret weapon of landscape photographers: the hyperfocal distance. Given a particular aperture, the hyperfocal distance is the point you focus the lens at that gives a depth of field spanning from half that distance out to infinity. It sounds like magic, and the actual point you need to focus on varies with the film or sensor size, the lens and the aperture. You don’t have enough fingers and toes to do the maths. So you either use an online resource or an app to calculate it for you, or use the depth of field markings that the lens maker gave you.

Say I’m using the lens in the above photo and I want both a group of people and the mountains in the background to be sharp. So I want a depth of field from say 4m out to infinity. I twist the lens to find a pair of aperture markings that put infinity on one side and my closest distance at the other. Then set the aperture to match the marks – the point of focus is already set correctly. Job done.

Hyper

In this case I need f11 and my closest sharp distance is perhaps 3.5m. The actual point of focus of the lens is 6m, but I don’t care.

This also works well if you are taking pictures of things that occur a bit further away, but variable. Some sports or activities, for example. Set the depth of field to cover the area of the action and concentrate on taking pictures.

So there you are – sharpness made simples, and a way to make use of the cheap end of the camera market.

In perspective

Want to start a fight? Ask a few photographers what effect the choice of lens has on perspective. Perhaps not a fight, but you will get a lot of hearsay rules and theories. But, as we know, a proper theory is one that can be falsified and makes testable predictions.

So a camera is basically a pinhole sitting at some distance from a sensor or film. The angle of view is set by the size of the sensor and how far away it is from the hole. A big sensor further away from the hole can have the same field of view as a smaller sensor closer to the hole.

Angle of view

Since the distance between sensor and hole is basically the focal length, this explains why different sizes of film or sensor need different focal length lenses to get the same angle of view. For example, a 50mm lens would be a telephoto (narrow angle of view) on an APS-C sensor, a normal lens on 35mm and a wide angle on medium format. Or, to put it the other way round, a standard lens on a small sensor would have a shorter focal length than one for a larger sensor – see A and B in the diagram above.

Let’s ignore the sensor size for now and just look at the angle of view of the lens.

Angle 1

The lens we have fitted has a wide enough angle of view to take in both the person in the foreground and the building in the background. If I stay in the same position and fit a lens with a narrower angle of view, it gets just the person’s face and a small section of the background.

Angle 2

What you will notice though, is that the relative sizes of the person and the building do not change, you just get a narrower slice of the wider version. You can test this by taking the same picture from the same position on both a wide and a narrow angle lens. Or use a zoom. Enlarge the wide-angle shot so that the central portion matches the narrow-angle picture and you will find that they match perfectly. This is the falsifiable test. This means that perspective, in the sense of the relative sizes of objects in the frame, does not change with your choice of lens if you stay in the same position. All that changes is how much stuff you get in the frame.

So what does a wide-angle lens change? If you get close to the subject, it changes the relative sizes of the nearby subject and the distant background.

Angle 3

In this diagram I shoot a head and shoulders with a narrow-angle lens (the dotted lines). It can see a narrow section of the background, so the background looks quite large in relation to the subject. If I get close to the subject with a wide-angle lens, so that I still get a head and shoulders (the solid lines in the diagram), the subject is the same size but I see more of the background and it looks smaller in relation to the subject. What changes is called the diminuition – the rate at which objects get smaller as they get further away.

This is why we usually avoid shooting portraits with wide-angle lenses. If we get close enough to fill the frame, the relative size of things near and further from the camera changes. These could be the nose or an arm or leg. But we do use wide angle lenses for landscapes, where we want to give prominence to a foreground object (like a Joe Cornish rock).

So there you have it – the angle of view of the lens only controls how much you can fit into the picture, providing you stay in the same place. You can use the angle of view of the lens to control how big the background is in relation to the subject, but only if you move nearer or closer to the subject.

What does this mean? That perspective is controlled by position, not the field of view of the lens.

Are you sitting comfortably?

If you recognise that phrase you could be as old as me, although the programme ran until 1982 so you might equally be a spring chicken.

What’s the story? Or, to poke another meme, “I’ll tell you a story, about Jack a Nory…”.

We, as a species, love story-telling. I believe this because Yuval Noah Harari says so and so do Mssrs Stuart and Cohen in The Science of Discworld II. Their argument is that it was the cohesive power of a shared story that taught us to collaborate across family and tribal borders. It also led to religion, but that’s another story.

So what the Darwin has this got to do with photography? Narrative has power and people look for a story. Even in the absence of an available story, people will make one.

The desire for a compelling tale is so strong that we will choose the embellished story over the plain and more likely one. See Kahnemann and Tversky’s Linda experiment for further details.

The expression of this in photography is when people tell you what they see in an image. I’ve heard photographers talking about people telling them what their picture is about, in terms and directions that were a great surprise to the person who actually made the image.

Fish on grass

So why should you care? Well, your pictures will tell a story whether you like it or not. If you have a particular story in mind, you should either make it very clear or add words. If you do not, the viewer will make their own story, and it may not be the one you intended. If you care, you need to make your story more clear. But if you think of how many times you see an image without a caption or description though,you might believe that the story should be in the image.

You might also think that what matters is not the story you are telling, but that there is potential in the picture for people to make-up their own story. Obviously this doesn’t apply to news photographers, social documentary and so on – these people really do have a story to tell and will work hard to do it. For me though, I can try to add elements to my picture that will lead the viewer to make a story. So I can try to show a relationship, or show someone’s doing something interesting that will make the viewer ask themselves what is going on.

Waiting for the man...

Perhaps this is the second Golden Question – the first was ‘what do I see?’. This one is ‘what does it say?’.

Does every picture have to tell a story? No. But that leads to the third Golden Question of ‘why should I care?’ Which is the realm of landscape photography.

Picture story

We – blogs, podcasts, websites – spend too much time talking about the gear and not enough about what we bought the gear for: the pictures. So here is a picture and the story behind it.

This is my dad. Was my dad. It’s not a great scan, but that’s not the point. My dad worked a lot with his hands. He was an electrician and later a maintenance guy in a large supermarket. In between he built everything we had, including (with a group) the house we lived in. I never saw my dad without some sort of injury to his hands. He would have a black fingernail, or cuts and a gashed knuckle. Shaking hands was like being power-sanded.

Later in his retirement he got sick, partly possibly due to the asbestos he was exposed to – it used to be sprayed onto the steelwork in large buildings to make them more fireproof. But he was a tough old bird and the lung damage was just a thing. He coped with more diseases then would kill a brown dog and had more come-backs than a prog-rock band. His nickname was Lazarus. This weekend would have been his birthday.

But that’s not the story. The story is a very simple one: this is my dad and these are his hands. He made stuff, he mended stuff and he held together a family.

Strong hands.