EFORE the days of TTL (Through The Lens) metering and automatic exposure systems, amateur photographers seemed to be obsessed with knowing what exposure was used for a particular picture. Back in the 1950s and 1960s most of the UK photo magazines included under the pictures they published details of the shutter speed, aperture and film used. Such details were required of contributors. I suppose it might have helped some people, but the chances of meeting the same lighting conditions to use the same exposure must have been pretty remote.
     I knew several freelance contributors to these magazines some of whom admitted to me that when they were sorting out prints to submit they couldn’t remember what speed and stop they had used, so they used to look at the general lighting of the picture, the depth of field, and make a guess. As far as I know, what they put was never queried.
     Back in the early days of photography when photographers lugged big wooden cameras and tripods around with them on an outing, exposure was very much a hit or miss affair. Even when dry plates appeared many of these didn’t even have a speed rating, they were labelled just Rapid, Standard and so on. Speed could vary between different makers, sometimes between different boxes of plates from the same maker, and even the ‘Rapid’ ones were painfully slow by today’s standards. There weren’t any shutters on the earliest cameras, though add-on shutters appeared fairly soon. Photography was a leisurely business. After focusing on a ground glass screen and inserting a plate, the photographer put a lens cap over the lens and selected his stop. His fastest was usually f/8, but many preferred f/11, f/22, f/32 or even f/64 if the lens stopped down that far, to get good depth of field in the scenic landscapes that were the most popular subjects. He then removed the dark slide, removed the lens cap, counted seconds or looked at his pocket watch till experience told him the exposure was about right, and then put the lens cap back on.
      The emulsions were completely insensitive to red light, and darkrooms were lit by a red filter in front of a lantern, or by a piece of thick red cellophane or red dyed cloth over a window pane, and development times were ‘by inspection’. When the negative looked dense enough it was washed and popped into the hypo bath to fix it.
      By the 1890s, the speed of emulsions had increased to the point where 1/25 sec at f/8 gave a nicely exposed negative on a bright day. Removing and replacing a lens cap was far too slow

A selection of exposure meters from the 1930s, electric, extinction and, at the bottom, a couple of actinometers from Watkins and Wynne.

unless you used a tiny stop, so shutters of various designs appeared. Emulsions were given speed ratings, in Europe usually to a system worked out by Hurter and Driffield and shortened to H&D, or to the Scheiner system.
      This put the poor photographer in a bit of a dilemma. A few ticks of the watch either way in an exposure of several seconds didn’t make much difference, but now emulsions were fast enough to make exposures in fractions of a second. Experience still counted, and some compensation was still possible with development by inspection. Many photographers with darkrooms still stuck to the older methods and carried on with open trays and development by inspection even as late as the late 1920s when the first panchromatic films came on to the market.
      But gradually, with increasing production of cheaper cameras, there grew up an army of amateur photographers who were a few steps above the family snapshotter but hadn’t got a darkroom and weren’t interested in the chemistry side of photography. They made use of the increasing number of chemist shops that offered a D&P (Developing and Printing) service, forerunners of today’s High Street one-hour labs. In large towns and holiday resorts these chemists were often agents for local large D&P firms who processed a dozen or more films at a time using huge tanks of developer, so development by inspection was out. All negatives were treated the same which meant that photographers needed more guidance about exposure.
      The first guidance came in the form of tables and calculators, either slide or circular. Yearbooks and magazines published tables of average exposures for different times of the year, at different times of day and under different conditions of lighting such as Bright Sun, Hazy Sun, Open Shade, Overcast and so on. They were usually based on the speed of a ‘standard’ plate or film. If you used a ‘rapid’ plate or film you cut the exposure by half. Tables and circular calculators were cheap and remained very

Three Westons, a Bertram and a Russian Leningrad 4

popular right up to the 1950s. Used intelligently they could give good results, but from the 1890s onwards magazines and books on photography were gradually urging keen amateur photographers, as distinct from family snapshotters, to measure the light, and this needed some form of exposure meter.
      Appearing at more or less around the same time in the 1890s were the actinometer and the extinction meter. The actinometer was an incident light meter. You put a piece of sensitised paper inside a container, many of which were shaped like a pocket watch for ease of carrying. You inserted a piece of sensitised paper and watched through half a split window till the paper darkened to the same shade as a reference tint in the other half. You timed how long it took, and then used tables to convert this time into shutter speeds and stops, taking into account the speed of the plate or film you used. Like exposure tables, actinometers had to be used intelligently, but they were capable of very good results. What’s more you could use them in open light or in the shade, and it didn’t matter whether the sky showed bright sun, hazy sun or was overcast, nor what month or time of day it was.
      Numerous manufacturers offered actinometers, and early in the field was Alfred Watkins. Some people claim he invented it. His first actinometer was quite expensive but he sold more than 1400 in the first year. Then he came up with a cheaper version, his Bee actinometer. This was immensely popular, and sold by the thousands right through to the late 1930s, together with its main rival Wynne’s Infallible meter which looked very similar and used the same principle. Watkins wasn’t happy with plate and film makers who didn’t publish emulsion speeds on the boxes, possibly because one maker’s Rapid was slower than another maker’s Rapid. Also, he didn’t altogether trust the speed rating methods used by some other makers. Watkins ignored what the makers said was the speed and tested just about every film and plate available on the UK market using, it’s said, empirical testing with his own meters and not laboratory test equipment where his findings might be open to scientific argument by film makers with whom his speed findings disagreed. Not terribly scientific maybe, but very practical, and it appealed to a lot of people.
      He must also have had quite an altruistic attitude because he realised that many people starting to take an interest in photography hadn’t got much money to spare and might not be able

Three electric meters from the Far East.

to justify even the by then fairly low expense of his meter, so he published detailed instructions in a popular magazine of the time The English Mechanic and World of Science on how to make and calibrate your own actinometer.
      Unlike actinometers which measured incident light, extinction meters measured reflected light. They were made in various shapes, some circular and some like flat boxes, but probably the most popular shape was like a small telescope. Watkins offered an early one, a beautifully made instrument worthy of Victorian quality at its best. This was also made and sold in the US by C. Reinschild in New York. These meters are quite rare however compared with the much cheaper telescope type typified by the Drem Justophot and the Practos. They rivalled actinometers in popularity with the advantage that they were much faster to use, and could be used in quite low light levels. They remained popular for about 50 years up to the early or mid 1950s. A few 1950s cameras had extinction meters built-in under the top plate. Early Paxettes are one example and I believe some models of Regula had them as well.
      Extinction meters varied in size, shape and method of use, but they all worked on the same principle. You pointed the meter at the scene you wanted to take and looked through the eyepiece. Usually you saw either a number, or a series of numbers, in light grey or green, or sometimes bright red, against a black background. With a single number you turned a control and the number got fainter. You stopped at the point where it was only just visible, and then consulted scales on the outside of the meter to find the exposure. If there were a series of numbers they got fainter as they progressed, and you chose the one that was only just distinguishable before consulting the scales. Another control was for setting the emulsion speed, H&D or Scheiner on the earlier ones, DIN or ASA on the later ones. They were robust, and there was very little to go wrong with them. Many of the early ones which have survived are still in working order.
      They had, however, two disadvantages. They didn’t allow for different people having different degrees of ‘night vision’, the ability to see dimly lit things. They also didn’t allow for the fact that the longer you looked through them the more your eye became accustomed to the dim numbers and the more numbers you could see. Nevertheless, they were less expensive than the

Two dial exposure calculators from Johnsons, one in their pocket Photographic Handbook for 1956, and the other made in white plastic.

early photoelectric cell meters and remained popular till they were finally ousted in the 1950s by a flood of cheap mass produced selenium cell meters. Another case of cheap mass production in the electronics field bringing down prices and achieving mass sales, to the benefit of the user.
      Photoelectric exposure meters came in the early 1930s. One of the earliest was the Electrophot made in America by Rhamstine, closely followed by the famous Weston range. On the European continent meters were made in Holland, France and Germany, and in the UK there was the AVO and the Chum among others.
      The early photoelectric meters all came from instrument making firms, and were made almost to laboratory standards. They were fairly heavy, and the movements were quite delicately balanced, so you had to be careful not to drop them or you broke the needle pivots. They also cost quite a lot of money. It wasn’t till the late 1930s that electric meters more affordable to the average photographer started to come in.
      In Europe, production of exposure meters for amateur photographers was stopped by the war, and though it revived again after the war, it wasn’t long before European makers just couldn’t compete with a flood of cheap selenium cell meters from Japan. They weren’t as well made, nor possibly as robust, as the earlier instruments, but they were cheap, usually reliable and, if used sensibly, gave accurate exposure readings.
      One of the drawbacks of a selenuim cell meter is that its sensitivity falls off rapidly in low-light conditions, but this was countered by the introduction of CdS (Cadmium di-Sulphide) cell meters which were much more sensitive but needed a battery. Gradually, though, separate meters became fewer on the market as more and more cameras appeared with built-in meters.
      At first these were separate from the camera controls so you had to take a reading and transfer it to the shutter speed and aperture though some, Canon is one example, had an external mechanical coupling to the camera speed dial, and with others the speed dial was turned to line up the meter pointer with an f-stop number which you then set on the lens. Later, smaller and more sensitive cells were housed in the pentaprism cover of SLRs to give TTL (through-the-lens) metering leading eventually to automatic exposure.
      Today, only professionals, and camera collectors who like using old cameras, use hand-held meters. If you like using old cameras a meter is, if not essential, at least a great help in determining the correct exposure. You can find older meters, usually at camera fairs and occasionally in flea markets and secondhand shops, quite cheaply, though many selenium cell meters begin to lose their sensitivity as the cell ages. Even so I've found that quite a few 'dead' selenium meters can be brought back to life by attention to the electrical joins inside or, where the cell makes contact by being pressed against a contact plate, by cleaning the contact surfaces with switch cleaner.
      CdS meters don’t lose sensitivity but most have the big drawback that they were designed to use mercury batteries which are now no longer available. Most will work with alkaline batteries, but they won’t be all that accurate because they were designed to run with the lower voltage mercury batteries. Zinc-air batteries will also work them, though these have the disadvantage that once the protective strip over the air hole is removed the battery has a relatively short life.
      Much the same applies to cameras from the 1950s and 1960s with built-in CdS meters, though some designs used a ‘bridge’ circuit for the meter which isn’t voltage sensitive. It depends on balancing the voltage either side of a Wheatstone ‘bridge’ so they will work quite happily with 1.5 volt alkaline batteries.
      As well finding a good meter for use, old meters, calculators and exposure tables make a fascinating sideline collection to add interest to any camera collection.