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Land and the SX-70

An incredible man and the unbelievable camera he built.

by Julian Edgar

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This article was first published in 2002.

To tell you the truth, while I have been an interested photographer since being given a Kodak 126 Instamatic at age 11, I never saw myself getting too excited by old cameras. I mean, sure, like old cars, old cameras reflect the technology and society that gave birth to them, but as to actually collecting them to admire, well, no - not me.

But when my partner Georgina decided that she wanted to start a collection - of anything, basically - I nominated 'cameras' as one of the categories she could consider. And she did more than just think about it - right now she's got 28 cameras awaiting the (yet to be purchased) display case.

And while I like many of the cameras in her new collection, it's the Poloroid SX-70 Land Camera that just blows me away. Not only is it a masterpiece of styling and technology, it also was a camera simply freakishly advanced for 1972. And incidentally, like all of the cameras in her collection, it can still be picked up for chickenfeed at secondhand stores, garage sales and through the classifieds. I think her SX-70 cost her (actually, when I remember, I paid for it!) about thirty bucks.

The nearest equivalent of the SX-70 in automotive terms is probably the NSU Ro80 - that marvellous sedan that would have had sufficient impact on automotive design history just for its aerodynamics alone... an influence that could be clearly seen in sedans in the following 20 years after its 1967 release. But the Ro80 was far more advanced than in just in its body design - it also had front-wheel drive rotary power, in-board front discs brakes and a semi-auto transmission.

Unfortunately the Ro80 sent its company broke - but with the revolutionary SX-70, the same fait was not to befall Polaroid and its incredible driving force, scientist and inventor Edwin H Land.

From Polarising Sunglasses to Instant Cameras

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Edwin Land was one of those rarest of individuals in the 20th century - he was both a scientist and an inventor who had a public profile. Making his achievements almost unique was that his inventions also earned him money... large sums of it.

Land was born in 1909 in the USA, and died in 1991. He attended Harvard College but had little interest in a traditional education. Instead, he intensified his learning at the New York Public Library, a path also adopted by that other most famous of American inventers, Thomas Edison. (In fact, Land and Edison hold the records for the most US patents ever granted.)

Land, while still a physics freshman, decided that the area of polarisers could be explored. (A polariser aligns all the rays of light in the same plane.) Together with a Harvard physics instructor, George Wheelwright III, he patented a new plastic polariser dubbed Polaroid, the beginning of Land's lifelong interest in how light behaved.

It is said that Land saw a great safety use in Polaroid material: if car headlights were fitted with Polaroid sheets, the glare affecting oncoming drivers would be much diminished, allowing pedestrians and other road obstacles to be seen. However, for the headlights equipped like this to still throw the same amount of light, bulb wattages would need to be doubled, increasing fuel consumption and no doubt raising other associated costs. That ended the idea.

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However, low-cost polarising material did find a very effective use - in sunglasses. Still the best sunglasses available today, Polaroid sunglasses substantially reduce reflections from roads, glass and water, allowing the wearer a much clearer view. The effect was actually discovered by accident, when a colleague took a piece of polarising material along on a fishing trip. He found that by using the polarising material, he could see straight through the surface reflections on the water, allowing him to see the fish he was trying to catch!

In 1935 the American Optical Company licensed the use of polarisers from the Land-Wheelwright company for use in the manufacture of sunglasses. Kodak also started using the material in polarising filters - photographic devices that would reduce reflections. (These days, polarising filters on cameras are most often used to saturate colours, but then there were of course no colour films.)

In 1937 Land set up the Polaroid Corporation, located in Boston, New England. The company concentrated on finding uses for polarising materials - some of the products included anti-glare desk lamps, dermatology lamps, and variable density windows. Later he produced aviation goggles - by 1944, WW II products included the polarising filters used in gun-sights, rangefinders and binoculars. (After the war Land also helped develop the camera used in the famous US spy plane, the U2 - a camera that could perform the equivalent feat of detecting a golf ball at about 2 kilometres...)

But it was in 1944 that Land conceived the idea of instant photography.

Instant Pictures

Land's 3-year-old daughter, asking why she couldn't see the photo that had just been taken of her, prompted the concept of instant photography. Said Land, "As I walked around.... I undertook the task of solving the puzzle she had set me. Within an hour, the camera, the film and the physical chemistry became so clear to me."

At that time, and as now with normal film cameras, before a picture could be viewed the film had to be processed, fixed and then printed, with the resulting pieces of exposed photographic paper then also developed and fixed. But it was only three years later - in 1947 - that Land demonstrated his one-step camera and film at a meeting of the Optical Society of America. The assembled experts were stunned.

Less than two years after that momentous event, the Polaroid Camera Model 95 and Type 40 Land film were on sale at a cost of $89.50. The camera weighed 1.8kg(!) and produced sepia brown silver images. While still a very expensive camera, the sub-$100 pricing was a strategic device. Said Land later, a product "must retail at just under $100. You see, you can't make money selling to the very wealthy, there are too few of them. You can't make money selling to the poor either."

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The camera was an immediate success; by 1950 a million rolls of instant film had been manufactured.

As implied by that massive weight, the first Polaroid cameras were monsters. These cameras continued in an evolutionary procession until the early 1960s - Georgina has the one shown here in her collection, a Model 800. Closed-up it's a relatively petite 250 x 150 x 70mm - but unfold it and it's a huge 250 x 200 x 150mm... a very impressive sight! Each film roll produced eight 7.2 x 9.5cm prints.

And, while 'packfilm' cameras (including those with colour film) replaced the early 'rollfilm' designs, none of the models were quite as revolutionary as that first camera... until the SX-70.

The SX-70

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Released in 1972 and discontinued in 1977, the SX-70 was in many people's opinions Edwin Land's masterpiece. It was the world's first Single Lens Reflex folding camera - let alone, instant photography SLR - and it packed into its sleek lines a simply awesome amount of technology and brilliant design.

Firstly, despite producing prints 7.9 x 7.9cm, it folded away into a package very close in size to a paperback book - 18 x 10.5 x 4cm. (Incidentally, the print size is important because in a Polaroid camera, no negative is formed - the print size is what you get; no further arguments.) It was said that one of the SX-70's design criteria was that it fit inside a suit coat pocket; additionally its prints had to be self-contained (ie not need the peeling apart of layers as previous Polaroids had required) and be able to develop in full daylight.

The film pack had to contain a thin but powerful battery (so that every time you loaded a new film, a new battery went in as well), the camera had to focus closer than any normal camera would, and the SLR design required that the photographer see the image moving in and out of focus as the lens adjustment was made. Additionally, an automatic exposure program needed to be used, one that required an electronic sophistication not seen in any contemporary mass-market camera.

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Using the Polaroid Corporation's words, "The Polaroid SX-70 Land camera was the first fully automatic, motorised, folding, single lens reflex camera which ejected self-developing, self-timing instant colour prints".

The SX-70 didn't just embrace one or two new idea - there were literally dozens of breakthroughs needed for success.

The camera used a 4-element glass lens that gave a minimum focusing distance of just 26.4cm. The electronic shutter (an unheard of advance in consumer cameras of the early Seventies) gave a programmed auto shutter speed from 10 seconds to 1/175th of a second with an aperture range of f8 - f22. Curiously, the first model didn't have a tripod socket, although an accessory giving this function was available to clip around the camera body.

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The SX-70 that is in Georgina's collection is this very first model. When we discovered it in a junk shop we weren't even sure if it was a camera. Folded up, it looks a little like an early transistor radio - but without any dials, markings, or even brand name. With leather inserts in its chrome-plated body, it is well-made and at 700 grams, is quite heavy for its size. You can feel its quality... even while not knowing what it is.

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By looking at the shut lines and hinge pins that were visible, it could be seen that the box should open - but how to do that? Eventually we realised that pulling on the upper rectangular section popped out a piece - but even that didn't reveal much.

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But lifting that section again gave the trick away - the camera suddenly unfolded itself. Up popped the front panel revealing a red shutter release button, focus wheel, lens and exposure adjustment button. Above that, the section that first lifted now revealed itself as the viewfinder, while rubber bellows between the now displaced camera sections appeared, making the interior of the camera lightproof. A lever is used to lock the camera into its opened position... and that's about all that can be seen. However, press another small lever and the front of the camera drops open further, revealing the space into which the film pack is inserted.

It's a bizarre looking piece of equipment, one which for all the world looks like it should have stayed in the design studio. But that's just a reaction from someone used to seeing a camera as a traditional black or silver box, with a shutter release button on top and a lens staring straight out from the front face. This camera looks more like a model of an avant-garde tent, or a sculpture destined for a museum of modern art...

In fact, some commentators have drawn parallels with its shape and the contemporary American technological philosophy: "The SX-70, with its angular lines, a viewfinder that evokes the subtended angles of vision itself, and its sci-fi metamorphosis, is a charming, tangible embodiment of the dated futurism of the postwar American consumer era, which envisaged a 21st century of tidy suburban homes, ubiquitous electronics (and robots!), and at-all-angles Jetsons-like interiors."

How It Works

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Before looking at how the SX-70 actually works, here's a quick guide to the light path through a conventional Single Lens Reflex 35mm camera - the sort where the lenses are normally interchangeable.

Up front is that large lens, which also contains the iris (the assembly able to be varied in 'hole' size to let different amounts of light through). When you're looking through the viewfinder, the iris is always fully open. Behind the lens - in the body of the camera itself - is a moveable mirror that reflects light upwards onto a focusing screen. The focusing screen is viewed through a system of angled mirrors on top of the camera - called the pentaprism.

When you press the button, the lens iris immediately shuts down to the selected aperture, the mirror flips up out of the way (also blocking your view through the viewfinder), the shutter positioned directly in front of the film opens, the film is exposed - then the process all happens again in reverse. The shutter closes, mirror flips back down, and the iris opens.

So even in a conventional SLR, a lot happens in the moments after you press the button. Now since all Single Lens Reflex cameras work on the same basic principles, how does the SX-70 do all of that? The answer is that its design moves some bits and pieces to unusual locations, and ingeniously arranges other components so that the camera can be folded flat.

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This diagram, based on the original US patent application for the camera, shows the approach taken. In this picture the camera is shown set up for composing the image. The lens (pink) focuses the light on a flat mirror (green). Unlike a conventional SLR, this mirror doesn't move. Directly behind the lens is the shutter (light green). During the composing of the photo, the shutter stays fully open.

The flat mirror (green) reflects the image down onto the yellow panel. This is a very tricky piece of technology - on one side (the side facing upwards in this view) is a focusing screen, while on the other side is another mirrored surface. Below this device sits the film (grey). The viewfinder comprises a curved mirror (blue) and a viewfinder lens (red).

The photographer views the image formed on the focusing screen, sitting flat on top of the film. To directly quote from US patent 3,722,389:

"A normally open shutter (light green), mounted behind the objective lens (pink), permits light to pass through the lens and across the chamber until it impinges upon the mirror (green) which is positioned to reflect the light onto the focussing screen (yellow) to form an image of the scene to be photographed. Light emanating from the image formed on the focussing screen (yellow) is reflected upward towards the planar [ie flat] mirror (green) from which it is reflected towards [the top viewing housing] until it impinges on curved mirror (blue). [This reflects] the light rearward to the eye station...which is then magnified by the eye lens (red)."

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So the large flat mirror not only helps form the image on the focussing screen, but also allows the photographer to see it - it's used in two different ways at the same time!

And what happens when the picture is taken?

First, the normally open shutter (light green) closes. Also shut off is the opening that previously let light pass out of the camera body to the viewfinder, so making the camera body light-tight. The focussing screen/mirror is then flipped upwards until it rests against the flat mirror (green). This both uncovers the film (which formerly had been sealed off from any light) and also reflects the image onto the film, courtesy of the mirror that is present on the other side of the focussing screen. The shutter then opens for the required length of time, the process then reversing itself.

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So how good is that? Not only does the optical system allow the largest film area for the smallest camera body (compared with the SX-70, even a spy camera like a Minox is huge when referenced to its film area), but it also uses a design that can be folded into a flat package! And not only that, but remember that the self-developing film was also technically unique, not to mention the motorised roller system that automatically ejected the developing picture...

I've run out of space, but take a look at this diagram from the (separate) patent for the film transport system - it gives some idea of the complexity of other parts of the camera. Not only could I write another article on this mechanism, but the chemistry of the film would be worth a series on its own!

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Truly, the SX-70 is an absolute technological marvel of engineering, a credit to the man who took such a monumental risk, a man who once said, "Don't undertake a project unless it is manifestly important and nearly impossible."

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