Making a card rangefinder

I have referred to this a few times, with links out to pages on t’interweb where these things are spoken of. The drawback is that the web resources seem to use maths, when what we want is simplicity. So here’s my version.

What you need is a bit of card (I know, the title was a spoiler). Anything from credit card to an index card will do (ask your parents what a card index was). The main thing is that the card has one good right-angled corner. You also need a tape measure and a second scrap of card or paper.

Find a nice vertical line – a door frame or the edge of a wall. Measure a distance of say six feet from it and stand facing the target line with your toes at the distance mark. I say feet, but you might also measure the distance in meters. Use whatever units your camera lens is marked in.

Hold the card out in one hand at arm’s length. Choose the hand you will be using when you do this for real with a camera. If you are likely to be holding the camera in your right hand and using the rangefinder in your left, then hold it out in your left hand. Let’s assume you will be using your left hand. Close your left eye and line-up the edge of the card with the vertical target. Without moving the card, close your right eye and open the the left. Hopefully the vertical target will appear to move along the card, away from the edge that was originally lined-up. If it moves the wrong way, swap eyes.

That second scrap of paper is used to mark where the vertical edge appears to move to. Pinch it against the main rangefinder card and slide it sideways until your distant mark appears to consistently move to the same place. Keeping the rangefinder card and the scrap of paper pinched together, mark on the rangefinder card a line for that distance. In this example, six feet. Change the distance and repeat.

Card rangefinder
Left picture is what you see with your right eye open. Right picture is with left eye open – mark the measured distance where the yellow card joins the white one.

You can now throw away the scrap of paper and keep the rangefinder. You have built a rangefinder that works for you and your eyes and will measure close distances with enough accuracy to focus lenses using their marked distance scale.

Here’s one I made earlier. Marked in meters and made to be held in the right hand (which is why the distances come in from the left).

Go ahead and make copies of the card so that you can keep one with each camera. Laminate them. Print the scale on the back of your business cards. Get the lines tattooed on your finger or mark them with a pen before you go out.

The only time you will need to change the card is if the length of your arm changes, or the distance between your eyes. Or you decide to become a pirate.

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.

The Golden Question

Have you ever been out with a non-photographer? You know, those people who keep walking when you stop. Have you ever tried to explain to them your affliction? Have you ever tried explaining it to yourself?

Try this: as you raise your camera to shoot, ask yourself “what is it that I see?”. That’s what the picture is about, so that’s what it should contain.

If you had to explain to a friend (a very patient friend, or even your non-photographer) why you were about to take this picture, what would you tell them? Imagine your friend didn’t know an f stop from a ‘we’re effing stopping again” and you had to explain in simple terms what you could see so that they understood. What do you tell them? What is the key thing that you saw? Imagine you asked them to stand in your spot. Show them how that thing does that, and that thing does this in relation to it, or whatever you saw. Imagine showing them the scene that is to become the picture.

Would they get a sense that you see differently (or even better)? Would they get a sense that you will turn the prosaic to the poetic with something you will do to the image later? Or will they zap it with their mobile phone, grunt a thanks and walk on?

It’s an interesting question – what can you see as a photographer that non-believers can’t? The wrong answer would be that you take the same pictures as them with a more expensive camera. The better answer is that you make a better picture – something that captures more, or better, what was visible.

Anglesey, Rhosniegr
What I saw was Bill Brandt.

So – next time you lift your camera, ask yourself what you see. Then take more of that.

A dog with two tails

So, I’m a lucky dog and I have a Nikonos V with a flash. As is usual with underwater flashguns it sits out to the side of the camera on a metal bracket that screws into the camera’s tripod socket. Most water is full of suspended silt, so you want the flash to light the subject alone and not the grunge between it and the camera. So that’s why the flash is out to one side on some sort of arm.

But I wanted two.

I’ve got the flash that came with the Nikonos, and very lovely it is too. It’s controlled by the camera’s light sensor, so it reads the flash exposure off the surface of the film. How easy is that? But I also have a second flash that has a slave cell. So the cunning plan is to mount the original flash to the left of the camera where it normally sits, but to find a way of mounting the second flash to the right. With a bit of luck I would get a main light / fill light effect.

Both flashguns use the same arrangement for locking to their bracket. They have an asymmetric pin that passes through a slot in the bracket and then turns to lock against sliding back out. The bottom surface of the flashgun has a raised ridge that then engages a groove in the bracket to stop the flashgun twisting. A large nut tightens the arm down against the bracket and locks them together. It’s a robust and strong fitting – just as well, as the camera rig will often be lifted by the flashgun.

So what I needed was a bracket that had the same slot and groove arrangement on both ends. Basically a bit of bent and machined alloy; couldn’t be hard to find or expensive, right? Wrongit was more than I was willing to pay.

So plan B was to find a bit of alloy and make my own. The alloy was easy – a bit of flat bar bought cut to length from eBay. Even the machining wasn’t too hard. I realised years ago that I was incapable of drilling a perpendicular hole and bought a proper bench-mounted pillar drill. My dad, bless him, had left me a biscuit tin full of assorted drill bits. It was easy enough to copy the arrangement of slots, holes and grooves from the original bracket. It needed a large clearance hole around the main flashgun connection to the camera, but that yielded to one of dad’s hole-cutters.

The final step was to bend the bracket downwards at a 20 degree angle. Flat alloy bar turns out to be really strong. I’ve got a small bench vice but it just started turning on its base. Dad came to the rescue again with his zombie-killing spanner. This is a large and long-handled pipe wrench. This went round the vice and gripped it. Pulling the alloy bar in one direction, the spanner in the other and with a knee on the bench to stop it falling forwards, the alloy gracefully received its 20 degree bend.

For some reason I have a small tin of white Hammerite paint. It was probably on sale. A couple of coats of that and the bracket looked almost purpose-made. Glue on a bit of neoprene sheet (used for repairing drysuits) to stop the camera twisting and to stop the tripod screw from falling out of the bracket when it’s off the camera, and Bob is my uncle.

Total cost around £5.

So what I have now is the standard flash held in its usual position, plus a second slaved flash that can be manoeuvred for fill-in. Or you could call it a major tangle-hazard.

Except, now I’ve made it, I wonder if it’s too wide.

Big arm

The key thing will be whether the flashes throw shadow from the two macro-framing arms. And that I can dive with it and not break bits off or get it caught in anything. I might have to bring the two flashes in closer to the camera. One way to find out – dive with it.

Except… my next dive is off a boat, and I’m not sure I want to be handling a rig this big. It might be better to wait until August, when I’m doing a shore dive. Which, embarrassingly, gives me time to make the MkII version. I think I need to bring both flashes in closer to camera. I will get less chance of using nice cross-lighting but the whole rig will be easier to handle and there is less chance of the macro arms casting shadows. I’ll have a look at the same time at the possibility of replacing the arm on the slave flash (the one on the left of the picture) with a longer jointed arm. This will let me put the slave light over the top of the subject while keeping the main light on the left.

And this, children, is why we use old milk cartons and sticky-backed plastic. If I had spent decent money on this I would be forced by pride to keep using it. But I will get another strip of alloy for a fiver and make the new and improved model. I count this as only mildly percussive learning, which is a bonus. Never too old to make mistakes, that’s me.


This is the Mk II version. Looks a lot easier to handle, doesn’t it? That piece of white stuff with the numbers on? That’s a rangefinder card.

Mk 2

No turn left unstoned

What is the worst thing you can say on social media about photography? I think it’s “what do you think of my pictures?”. Let slip the trolls of yawn.

The best advice I heard on advice was from Abby Honold on Twitter, who said “don’t take criticism from people you wouldn’t ever go to for advice.”

This was covered in more depth, and a lot more characters, by Agnes Callard. She makes a distinction between advice, instructions and coaching. You give someone instructions on how to achieve a goal that leads to a further goal. Her example is telling someone how to get to the library. Ours could be “this is how you load film into your camera”.

She defines advice as combining the impersonal and the transformative. You could think of it as “instructions for self-transformation”. I believe that she is saying that instructions are how to do a thing. Advice is instructions on how to improve in your chosen direction. This makes coaching advice given by someone who has a relationship with you and some investment in your development.

So what does a self-professed expert in photography whom you have never met or spoken to give you instructions that develop you along your chosen path? Or do trolls seek prey? Does the Pope shave in the woods?

I think the answer, on any kind of open forum, is not to ask for general advice or criticism. If you do ask, make it specific: limit the scope. Asking “what do you think?” encourages people to do something they are not very good at and what you get is opinion, not advice. Ask a specific like “is the contrast too high in this shot?” or “does this need more depth of field?” and you are more likely to get a relevant reply. Be aware though, that unless the respondent really knows what they are talking about, you might be listening to an uninformed opinion.

How do you tell if an opinion is useful? The criticism should be of the work, not the photographer. It should describe what an improvement might look like. It might describe some of the difficulties you encountered, which shows the person has experienced them too.

If you want to here criticism done right, listen to some episodes of the Shutters Inc podcast. Try episode 437 as a starter. The pictures are on their website, so you can see directly what Glynn is telling Bruce. This is constructive commentary about the pictures, delivered in a form that can be directly used to make changes. There is also a comparison picture at the end where Glynn edits one of the pictures to show what he was describing. Stuff like this you can carry around in your head to use when it’s your turn to take pictures.

And perhaps a good response to anyone who does give you a piece of their mind is to ask how they did it differently and show you examples. We can all learn, but we should be learning how to improve rather than fight.

No path
So what do you think of my picture? Or does it lead us nowhere?

Or there is always the mature and considered response my old boss used to give to people he disagreed with – “go stick your head up a dead bear’s bum”. Which is completely contrary to the previous paragraph, but funnier.

Stretching Benner’s box

I’m back to talking about how we learn to be better photographers. I have seen loads of resources that will tell you how apertures and shutter speeds work (guilty) but not how to get beyond them. Knowing how the tools work is a necessary part of getting better, but doesn’t confer goodness in itself. You do need to be a master of the tools, but that won’t make you a master of the craft.

We could tell people to go off and get 10,000 hours of practice, but effort without reflection is just effort. You could just end-up being good at changing the settings on your camera. A brief aside – I was listening to a podcast (name withheld to avoid blame) with the hosts discussing cameras. Nowt new there then. Except they were describing them in terms of how nicely they worked. This one had a smooth film advance; that one had a nice finger grip. This is cameras as jewellery and nothing to do with photography. What chance does anyone have of improving their art if the lesson is that you need a ‘nice’ camera? How does a beginner feel if their camera is not on the approved list? </rant> Let’s dismiss it as camera porn.

The reasons for my thinking about this are that I helped teach a basic Photoshop course a few summers back, plus I get told by people that they would like to know more about how to do photography and want to get better at it.

Turns out that there was another skilled profession that used to be thought of as only needing a bit of craft skill. And then someone described the stages of transition from novice to expert and recognised that these people spent more time in critical situations and applied an equal amount of expertise as their previously-thought masters. Meet nursing, and Pat Benner.

What Benner described (based on the work of the brace of Dreyfuses) was the stages in development from ‘follow the master’ to ‘be the master’ (Zen and the art of professional development – my new book will be out in the Autumn). The model describes what can be expected of a person at a certain level and how they would demonstrate their expertise. If I rework these to refer to photography, this is what you get:


  • Beginner with no experience
  • Taught general rules to help perform tasks
  • Rules are context-free, independent of specific cases, and applied universally
  • Rule-governed behavior is limited and inflexible
  • Example behaviour is “Tell me what I need to do and I’ll do it.”

Advanced beginner

  • Demonstrates acceptable performance
  • Has gained prior experience in actual situations and can recognise recurring meaningful components
  • Principles, based on experiences, begin to be formulated to guide actions


  • Typically someone with 2-3 years experience in the same area or in similar day-to-day situations
  • More aware of long-term goals
  • Gains perspective from planning own actions based on conscious, abstract, and analytical thinking which helps to achieve greater efficiency and organisation


  • Perceives and understands situations as whole parts
  • More holistic understanding improves decision-making
  • Learned from experiences what to expect in certain situations and how to modify plans


  • No longer relies on rigid principles, rules, or guidelines to connect situations and determine actions
  • Much more background of experience
  • Has intuitive grasp of photographic situations
  • Performance is now fluid, flexible, and highly-proficient

The different levels of skills reflect changes in three aspects of performance:

  1. Movement from relying on abstract principles to using past concrete experiences to guide actions
  2. Change in the learner’s perception of situations as whole parts rather than in separate pieces
  3. Passage from a detached observer to an involved performer – no longer outside the situation but now actively engaged in participation

These are all well known in education. There has been much research and argument both for and against Benner, but in general these are the stages by which we progress from beginner to guru.

This is all very well, but where’s the box? Meet Dunning and Kruger. Their theory and research says that we are all incompetent to some degree. What changes is our actual level of competence and our self-awareness of how much we know within the total space of what can be known. Basically, people with less competence in a subject tend to over-estimate their actual competence. As competence grows, one tends to become more aware of how there is that you don’t know. This helps explain why people feel like imposters. It also explains why people who know just a little about something can speak with great certainty, while experts are aware of all the uncertainties and so speak with more hesitancy. Take comfort in this – if you have ever been criticised by someone who seems absolutely set in their opinion and convinced of their correctness, they probably know less than they think. Just be aware, before you call them an eejit, that your box is only slightly bigger than theirs.


So there’s the box: it’s the bounding box around what we know, within the space of what is available to know. Benner provides the framework for expanding the box. Indeed, Benner provides a method for recognising what stage of expertise you might be at, so that you don’t get trapped into thinking you already know everything.

And the title? Stolen with pride from a senior nurse and educator in health sciences who used it in a lecture to nurses.

Why should you be interested in this? You just want to take pictures, right? If you want to get better at it, then learning how to learn is an important part of learning.

Shoot back
Curiosity never ends

Enough! My box in this area is so small it approaches the Planck limit (really; no false modesty). Get out and take some pictures, but be mindful of what you are doing and what results you got. You could be stretching your own box.

10,000 hours

So, the story goes that you need to practice something for 10,000 hours to become excellent at it. The counterpoint says that if you are rubbish at something and keep being rubbish, then at the end of 10,000 hours you will still be rubbish, but older. The improvement comes not from practice, but from reflective practice.

How does one reflect as a photographer? Not with a catadioptric lens. One reflects by comparing one’s results with one’s intentions and trying to bring them together.

Have you ever looked at your negatives or the histogram of your digital files? Do you, like me, tend to underexpose? If you are shooting digital, do you push the exposure as far to the right of the histogram as you can get it?


What do you struggle with most? Movement? Exposure? Focus? How could you try one small thing to improve, so that you can see if it makes a difference? The good news is that, using digital, practice is effectively free. The results can also be immediate, so it’s easier to iterate the learning loop of try, see, think, try. The very gods of decision making, Kahneman and Tversky, say that rapid feedback of results is fundamental to making good decisions and learning. Or perhaps better stated that slow feedback leads to more errors – see people fighting with a central heating thermostat, for example.

Do you think about photography when you are not taking pictures? Not the bit where you wish you had shinier kit, but the imagining of what you would do right now with a camera in your hand. When you look at a thing, think about how you would frame it and what you would do with tones, textures and colours. What would it look like with a slow or fast shutter, or a deep or shallow depth of field? Try guessing what the exposure would be outside the window or across the street. It’s all very well talking about sunny 16, but do you know how sunny it has to be? And what happens if you are under trees or near a building? Knowing what the correct exposure would be is useful, but perhaps more useful is knowing the difference between light and shade. It means knowing that you can blow a background to white by shooting in the shade, or dropping it to black by shooting in sunlight.

This is all about readiness. It used to be knowing which way the aperture scale turns on your lens, or which way to turn it to focus closer. It meant knowing which way the shutter speed dial turned and if you could set it without looking. I suppose with digital it means knowing which of the control wheels or buttons does what, without having to search or even look. My own digital SLR has the usual smattering of controls, arranged mostly in a logical order (unlike a Ricoh Mirai), but I have still labelled two of them with white marker to make it obvious which controls the metering area and which the autofocus point.

Alongside the ready ability to use the camera is a familiarity with how to obtain certain results. What’s the best shutter speed for panning a moving object? How much fill-flash do you need in direct sunlight or in the shade? What’s the best way to capture flames or smoke or the wriggly air you get with heat? How far out of focus can a face be if the eyes are still sharp? What about fireworks or light trails?

Rally car at night, sparking as it lands at the bottom of a hill.

I guess the military parallel is that we would all like to be snipers, but we learn by firing tracer so that we can see where our bullets are really going. With the advantage that tracer can be corrected even while you are doing it. So we look at our pictures and think about what we would do differently, or we imagine ourselves to be taking a picture so that our heads get the practice even if our hands are carrying the shopping.

So I guess this is the biggest argument for using digital cameras to learn photography. I know there is this big movement to ‘really learn the ropes’ with a film camera (which has driven up the prices of ‘training cameras’ like the Pentax K1000) but I think most would be better off using a digital camera that allows manual control.

Will we be better photographers? Yes, better than we were. Will we be great photographers? Only other people can decide that. Don’t worry about it, see yourself improving and take pleasure in that.

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