How to make a point-and-shoot camera in 1961
Today I’d like to show you what might be my very favorite camera. This is an Olympus Pen EES-2. It’s a 35mm point-and-shoot camera from the late 1960’s and there are two remarkable things about it. The first is that this is a half-frame camera. Rather than expose the typical 36 by 24mm section of film (the standard 35mm still image) it splits that in half and shoots an 18 by 24mm frame.
The upshot of doing this is a slightly smaller camera (?) and supposedly the Pen name comes from the camera’s diminutive size. [said ever-so-skeptically] I mean it’s not that small in the grand scheme but I... I guess I’ll roll with it. Oh, citation needed. Interesting. Anyway, my favorite consequence of halving the frame is that you get double the exposures on every roll of film. That’s pretty neat! You’ll see that the exposure counter goes to 72 rather than the typical 36.
However many exposures are on the roll you’re putting in the camera, this camera will let you take double that! Half-frame cameras were something of a fad in the 1960’s, but the fad would quickly die out. Frankly, I’m not sure why. You’d think people would appreciate getting double the exposures with every roll of film, even if it meant a slight reduction in quality. I mean, for basic family photos and snapshots a half-frame still holds plenty of detail. These are some of my favorite shots I've taken with this camera; I’ve enlarged them to 8X10 size and they’re still sharp-as-a-tack.
Actually, as a matter of fact, the sideways film frames this shoots are the same size as a 35mm motion picture frame. And back in the day we were regularly blowing those up to movie screen sizes. Because, ya know, movies were shot on this film stuff.
If I were to guess what caused the demise of the half-frame concept, it would be that unlike virtually all cameras which orient the frame so that it matches the camera’s orientation, this one is backwards! Holding it up in the natural camera-holding position produces... a portrait frame, and if you want landscape frames you need to turn the camera sideways. That’s a bit awkward, and since people tend to want a wider-than-tall image, this may have been seen as quite a downside back in its day.
There were some half-frame cameras that got around this by running the film vertically through the body, but as a result they had wildly different form factors from what people were used to in a camera. There’s really no way to get around this basic shape, so while you might be able to move controls around and make this its more natural orientation... that would still be weird. For what it’s worth, I find this pretty interesting from a creativity perspective. It’s easy to overlook turning a camera sideways for a portrait shot, but that’s this camera’s natural orientation so you almost have to consider it.
As it happens, Kodak recently released a point-and-shoot half frame camera so I suppose the idea might be coming back in vogue with the resurgence of film. Especially since it’s getting kinda pricey. One thing people like to do with this format is plan images in pairs and print them together like this, though frankly I’ve never really considered that and just treat them as individual images when I’m shooting. I think that got started because most film processing labs and scanners really don’t know what to do with half-frames — despite the fact that the film edge markings clearly accommodate them and have since forever ago! so the roll gets scanned or even printed as 36 pairs of images. But c’mon, folks.
You can crop them. Anyway I’m still talking about the half-frame part, and that’s not nearly as interesting as the fact that this camera has fully automatic exposure control, yet it doesn’t need any batteries. In fact there’s nowhere to put them because this is a light-powered camera. OK, powered might be a stretch - you still wind the film manually with this thumb-wheel, uh, this crank is for rewinding at the end of a roll... basically the film-handling bits are all human-powered.
But the shutter speed and aperture are set automatically. It will even prevent you from taking a picture if there’s not enough light - a little red flag pops up in the viewfinder, and a mechanical interlock prevents the shutter from releasing. This is a true point-and-shoot camera, completely automatic (aside from focusing) despite not needing a power source and being entirely analog.
[shutter clicks] You might be wondering how this works. Good thing you clicked on this particular video ‘cause I’m gonna tell ya! But first, a one-paragraph explanation on camera basics. Photographic film has a certain sensitivity to light, and to form images correctly on the film, you need to control how much light hits it during exposure - too much, and the image will appear bright with little detail, not enough and an image may not form at all.
A camera has two means of controlling the exposure: a variable lens aperture which changes how much light is allowed through the lens, and how long it keeps the shutter open and exposing the film to that light, known as the shutter speed. Adjustments to these values are made in what are called stops, with each stop doubling or halving the amount of light allowed onto the film. For example, a 1/50 of a second shutter speed allows one stop more — twice as much — light compared to a 1/100 second shutter speed. That can be compensated for by closing the lens aperture down by one stop, which allows half as much light through it. Professional photographers might want to do that to increase the depth of focusing field, or they might want to open the lens wider and use a faster shutter speed to reduce motion blur.
This camera, though, well it handles all that for you. Most of this camera’s exposure control is done with the aperture. In its resting state, the aperture is closed all the way.
What you’re seeing in the center of the lens is the opening made by the aperture blades. This camera has a square aperture which is a little weird but it works just fine. The itty-bitty almost-pinhole is the lens in its most stopped-down state, ƒ/22. The aperture is mechanically linked to the shutter button, and as you press it in, the aperture opens up. When it’s all the way open, the camera lets as much light through as it can. In this case the widest ƒ-stop is 2.8.
Just to be clear, this is not the shutter. That’s behind the lens and we can’t see it here. The shutter remains closed, preventing light from hitting the film, except for that fraction of a second when you actually snap a photo. You can manually select different aperture values with this ring. You’ll notice that when I pick a value somewhere in the middle, the blades start to open with the shutter button as before, but now they stop opening mid-way.
This here is ƒ/5.6, a fairly typical setting. But, watch what happens when I switch this to auto mode. The aperture is back to opening all the way with the shutter button. But if I shine a little light into the camera's lens and press the button, well now the aperture doesn’t open all the way. If I make the light very intense, the aperture hardly moves at all.
Somehow, this is reacting to more light hitting the lens and reducing how much the aperture opens to compensate and produce equivalent exposures on film. That’s pretty wild. To understand how this works, first I want to show you something else. When using a fully-manual camera, to know what aperture and shutter speed settings you should use a light meter is awfully handy. This here is a simple handheld light meter which consists of a light sensor here, a dial with a buncha numbers there, and a simple display down below. The needle in that display moves depending on how much light hits the sensor, and by turning the dial so that the little red-circle-on-a-stick thing surrounds the needle, you end up with a chart of acceptable shutter speed and aperture settings.
Changing the film speed setting simply moves the aperture values independent of the rest of the mechanism which effectively factors in the film’s sensitivity. The reason I wanted to show you this particular light meter is that this also doesn’t use batteries. The sensor here is a selenium light cell, an early photovoltaic cell. Think of it like a really old solar panel. When light hits it, it generates a voltage and that’s what’s moving the needle. Basically all this is is an old-fangled solar cell hooked up to a voltmeter that’s been repurposed alongside a clever slide-rule-like chart handy to photographers.
The characteristics of the cell’s output are very useful in photography because it’s logarithmic; each doubling of light that hits the cell moves the needle the same amount. So if there’s twice as much light it will move the needle one ƒ-stop over, which of course realigns the chart by one stop once you move the circle-on-a-stick thing. A quadrupling of light would move the needle two stops over, an eight-fold increase would result in three stops of movement, and you get the idea.
The honeycomb lensing in front of the cell makes it most sensitive to a camera’s general field of view. I don’t know what exactly the frame is this guy’s looking for, but the idea is that you can just point this in the general direction of where you want to take a picture and it’ll give you decent exposure settings. It’ll be a scene average so more particular photographers would want to take that into account for high-contrast scenes, and might even want to bring this guy up to something in the scene that will register as a middle-gray and take a more selective reading. Oh and you definitely want to shade the sensor from direct sunlight as that will absolutely skew the reading. Now, you might have already noticed that the lens of the Olympus Pen is surrounded by a similar-looking honeycomb stuff. Intriguing, right? Now might be a good time to mention that the EE in EES-2 stands for Electronic Eye.
Let’s go ahead and assume that the honeycomb stuff is some sorta light meter (because it is). How could we design a camera which uses the mechanism of a conventional light meter to automatically set an exposure setting? Well, remember how the aperture functions? It starts out all the way closed, and it’s opened by the shutter button. But when enough light lands on the lens, something stops it from opening all the way. What could that something be? Well, through the Magic of Buying Two of Them, I have an already taken apart one right here which I can show you! Here is the light meter and viewfinder assembly from an earlier variant of this camera, the Pen EE-S. We have the selenium light cell here, and a couple of itsy bitsy wires connect it through a resistor to this… thing. Notice there’s a needle sticking out of it? Well, watch what happens when I shine more light onto the cell.
That needle moved! This is the same exact concept as the hand-held light meter, but rearranged, miniaturized, and stuck into a camera body. But hang on, how does that translate into an exposure setting? Surely there must be more to it. Well, through the Magic of Buying Three of Them, I have a not-yet-taken-apart-one right here! This is another EES-2, but in grey, and I need to disassemble it because the shutter blades are sticking and need to be cleaned. This process is fiddly and finicky, involving tiny little screws and also removing the lens’s front element.
Which is a pretty precarious proposition as focusing is accomplished by rotating that element and thus slightly unscrewing it from the body, so before you take it apart you absolutely need to set focus to infinity and mark the lens position somehow so you can put it back exactly where it was. If you mess that up, all your pictures will be blurry as heck. Ask me how I know! Anyway, once we’re to this point we can see the needle — barely. It’s tucked right up here.
Right now it’s free-floating, and you can see it react to incoming light. It really is just like the light meter we were looking at. But when I depress the shutter button, well the magic happens. An intricate series of linkages cause a pair of feelers to move upward towards that needle. The first feeler touches the needle and jams it against a stop right above it to keep it from moving. Then a second feeler with sloping, stepped teeth approaches the needle.
That second feeler is connected to the aperture mechanism of the camera, and where it stops along its journey upward determines how far the aperture will open. And the needle is what stops it. See where this is going? When there’s less light hitting the camera, the needle is farther to the right, which is among the skinnier parts of the feeler. That allows it to travel farther upward - notice how the thicker parts of the feeler are now above the needle. With the feeler in this high position, it opens the aperture blades a great amount. But as more light hits the camera, the needle is pushed farther to the left, so the feeler’s thicker parts will hit it first and thus it can’t travel as far upward.
That prevents the aperture from opening as much, reducing the amount of light that can travel through the lens to compensate. Each doubling of light hitting the lens pushes the needle one stop over, which in turn restricts the opening of the aperture by one stop, thus the amount of light that makes it through the lens remains consistent no matter how bright the scene is. Pretty clever, huh? A simple integration of a selenium light cell and analog meter mechanism into a camera body’s aperture mechanism allows for automatic exposure control. But you might have noticed that the aperture feeler has two sections to it.
What’s going on with that? Ah, well, this camera actually has two shutter speeds. It will either shoot at 1/200 of a second or 1/40 of a second, and that first feeler which traps the needle is what determines which one it will use. Oh, by the way, this arrangement is often called trap-needle metering. Probably should have brought that up earlier. Anyway, you might have caught that the first feeler itself had two steps to it.
If the needle is far enough to the right that the higher part of the feeler hits it, the shutter will engage with a delay mechanism which holds it open for just an itty bit. That’s the 1/40 of a second speed. Here’s how that works: winding the film puts the shutter mechanism under tension. When it releases, this small cam will quickly make a complete rotation, which rapidly opens and closes the shutter blades through this linkage. On that cam is a protrusion which will hit this piece of metal and stop its motion.
That piece of metal is attached to this spring-loaded brass weight, which right now I’m preventing from moving. When I let go of it, the force of the shutter’s spring will push the weight out of its way, and the shutter closes. The function of the lever and weight is to deliberately (and literally) get in the way of the shutter mechanism’s movement, with the mass of that weight providing a calibrated delay that slows it down.
But if the needle is beyond that first step, the feeler will travel a bit farther upward - just enough so that this lever will travel beyond this linkage and allow it to move. Now, as the shutter button is depressed, the weight and its stop are pushed out of the way by the linkage. With the delay no longer in the picture, the shutter mechanism fires in one swift motion. Let’s look at that again. With moderate light levels, the needle stops the feeler here so this lever prevents this linkage from moving with the shutter button. When the shutter fires, the shutter cam will slam into the weight, briefly holding it open.
But if there’s enough light, the needle stops the feeler here. And now that lever out of the way of the linkage, so it will actually push the weight out of the way as you press the shutter button and therefore bypass the delay. Take a listen to what those shutter releases sound like - the difference is a bit subtle, but see if you can hear it. At the slow speed, you can hear the shutter open and close as two discrete clicks. [two discrete clicks] But at the fast speed, you only hear one click as the shutter is opened and shut in one smooth motion. [one click] The transition between steps in the shutter feeler lines up perfectly with the aperture feeler’s little kink.
And this is designed to prioritize the higher shutter speed. The farthest right position represents a 1/40 of a second exposure at ƒ/2.8. That’s the widest-open lens at the slowest shutter speed. But as soon as there’s enough light to make a 1/200 exposure work, the aperture scale resets and we start again at ƒ/2.8. This won’t mean much to you if you’re not familiar with cameras, but for a consumer camera this design makes perfect sense as a 1/40 second exposure requires a fairly steady hand, but 1/200 is much more forgiving.
Best to use the faster shutter speed whenever possible. Ah, but what about that red-flag shutter interlock doohickey? How’s that work? Well, if there’s not enough light to take a photo, the needle won’t even reach the position of the feelers. That means they’ll go right past the needle when they start moving upward, and that jambs the shutter mechanism while lifting the little red flag up into the viewfinder. One of the things I really like about this camera's design is that its lens cap covers the light sensor so if you left that on it won’t let you waste the frame. Very nice.
Oh, and to explain the manual aperture settings, they’re marked “for flash” as that’s their main purpose. On manual settings the sensor is ignored and the shutter will always fire at 1/40 of a second. Using a chart on your flash unit and estimating the distance to your subject, you’ll set the aperture accordingly. The hot shoe on top was one of the things added for the EES-2. Now, you might wonder how the camera compensates for different film speeds.
There is a film speed selector ring on the lens and this model will meter for any speed between 25 and 400 ISO. How is it doing that? Well, watch as I change the film speeds. Notice how as I get closer to 25, the numbers are getting closer together.
Understand why? To make this work with different film speeds, Olympus didn’t need to do anything fancy like incorporate a variable resistor, instead... they just cover up parts of the sensor! It’s hard to see but the actual sensor only occupies half of the circle around the lens, and turning the speed selector is sliding a cover over it. When shooting 400 speed film, all of the sensor is exposed to light so it’s at its most sensitive. The needle will move as far as it ever will with a given amount of light. But when you use 200 speed film, which is half as sensitive to light, you need twice as much light to hit the film to get a correct exposure. And as silly as it sounds, just covering up half of the sensor surface will compensate.
That will make it so that twice as much light is needed to put the needle in the same position as before. See how that works? It’s basically just fooling the light meter into thinking there’s less light, so it responds by opening up the aperture by one stop for every half of the sensor you block. Cover up half again and now only ¼ of the sensor is exposed, so it is ¼ as sensitive as it was; perfect for 100 speed film. Leave only ⅛ of it exposed and you’ve dulled the sensitivity another stop, making it work with 50 speed film. And at the slowest speed setting, 25, you need 16 times as much light so only a tiny sliver - 1/16 of the sensor’s surface - is exposed to light. Perhaps the most remarkable thing about this metering system is how well it works.
Despite being a design originally from 1961, a design which is mostly mechanical but with a selenium light meter cleverly hacked into it, this camera still functions perfectly. That is, once I gave it a little help. A common problem that pops up after 40 or 50 years is gunk on the aperture blades, which jams the mechanism.
I needed to fix that on this camera when I got it; it’s very common but cleanup with isopropyl alcohol usually does the trick. Assuming it’s mechanically sound, though, this just… works. I’ve never taken a photo with this camera that wasn’t exposed at least mostly correctly. Negatives have decent and uniform density, color or black and white. About the only thing that occasionally happens is a bit of washout in high-contrast scenes, but that’s to be expected with a meter which simply averages the frame. So long as you aren’t shooting the fastest speed one of these cameras supports, you could compensate by adjusting the ISO setting upward, causing it to underexpose the image.
But leaving it set to your film’s box speed will almost always produce decent results. The lensing in front of the sensor is apparently very good at rejecting light from areas not in the camera’s field of view. Even shooting partially into the sun results in apparently decent exposures. I mean I’m sure I’ve done it several times and yet *all* the images I’ve taken with this are workable... exposure-wise at least.
Now I should note that Olympus wasn’t the only company making cameras that worked like this. The selenium light cell made its way into loads of cameras, even movie cameras like this one. But I’m nonetheless enamored with this particular camera. Its design and simplicity are just right in that sweet spot. And apparently Olympus did such a great job with this design that they’d slap it onto full-frame cameras like the venerable Trip 35. Once you get these side-by-side it’s clear that the design of the Trip 35 was more than just “inspired” by the Pen EES-2.
These are the same camera mechanisms just with different bodies and lens focal lengths. I mean even the lens caps are interchangeable. Oh! And the Trip has the same red flag which means it doesn’t fill the viewfinder because it’s too small! Oh right, and you’ll notice that the Trip... is barely any bigger than the Pen. I mean, I guess it’s enough to be significant but I’m really not sure that making a smaller camera was the true goal of cutting the frame in half. Anyway, I hope you enjoyed this look into these cameras.
There were quite a few Olympus Pen models back in the day, but it’s the EE series which intrigues me the most. Taking the concept of the humble light meter and using it in conjunction with simple levers, feelers, doodads, and whatsits to create a fully-automatic camera is the sort of genius that we don’t often see today. Some really interesting innovation can happen when you take two different technologies — and connect them. [oof] ♫ olympically smooth jazz ♫ Today, I’d like to.. Ouhh bleglebleblbblblblberblbulbb Vooooogue. Sa, sa said that really weird. Kodak recently released a point-and-shoot...
oh yeah I was ‘sposeda pick up the camar ba GAARRGHGHHGHGHGHG Though, frankly, I’ve never really considered that and just treat them as individual shots when I’m… ppbbt! I’ve made an error in the script! Uh, so anyway the roll gets processed or even printed… eugh… [some sorta beastly snort-growl] A light meter is awfully handy. This here… I can’t grab things correctly. When it’s all the way open, the camera left as much light through… Nope, that was just me not reading. So, apparently a lot of you giggle at "Pen EE-S" I gotta be honest, I'm not smelling what you're stepping in.
That's similar to "pennies" - pen, E. Pen E. The other thing you might be thinking of starts with a syllable that rhymes with "keen." I mean, at least it does in my neck of the woods.
Y'all are weird.
2022-09-28 12:10
