Silverbased

Projects and ponderings for film photographers

Archive for April, 2008


What Are “Series” Filters?

A photographer could lead a long and happy life never using filters at all. But eventually, many of us find we need a bit of color correction when shooting slide film, or want to try a red filter to give more drama to sky and clouds when shooting B&W.

Nowadays when you shop for filters and other lens accessories, it’s universal for their sizes to be listed in millimeters—reflecting the influence of metric-speaking Japanese and German optics manufacturers.

Yet if you flip through 50-year-old photo magazines, or root through the odd-parts bins at a vintage camera sale, you’ll start seeing accessories cryptically labeled Series V, Series VI, Series VII, etc. What are these weird sizes, and are they good for anything?

A Series Filter has Three Parts

A Series filter has three parts: An adapter to fit the lens; a standard filter disk; and a retaining ring

“Series” adapters were the most common American system for lens accessories in the middle decades of the 20th century. And they were actually a very cool, totally modular way of doing things. My googling has not turned up much history about Series accessories. So I’ll share the information I’ve been able to put together—but I’d be grateful to hear from anyone who can steer me towards a definitive source.

My suspicion is that (as with many other photographic standards) it was Eastman Kodak who established the Series system. In any event, Kodak became a major supplier of Series filters and accessories.

The idea of the system was this: Colored filters, close-up lenses, etc., were manufactured in a few standard diameters—as “drop-in” disks, without threads. You chose the Series that would cover your largest diameter lens. Then, a multitude of different adapter rings were available, sized to fit all your various cameras and lenses.

Each particular Series had one standard-sized retaining ring, to hold the filter disk into the adapter. Some retaining rings had both male and female threads, allowing you to stack additional filters. Conveniently, the retaining ring could also be replaced with a lens shade having the same standard Series thread.

Mix and Match Modular Parts

Mixing and matching modular parts. At right, a Series-threaded lens shade; can also be used without a filter

A few manufacturers put threads on their lens barrels that were “natively” standard Series sizes—thus no adapter was needed, just the retaining ring. Several Argus, Kodak and rangefinder Canon lenses adopted this system (and no doubt other brands I haven’t come across yet).

The dimensions of the system were specified in inches, not millimeters (this may resolve some mysteries you have with weird unidentified lens or filter threads). The different Series sizes were designated with roman numerals, and ranged from quite tiny (e.g. for cine lenses) up to moderately large. But Series V, VI, and VII seem to be the most common (and useful) sizes.

I measure their dimensions as:

Series V — filters 1-3/16″ (~30mm) — retaining thread 1-1/4″ (~32mm)
Series VI — filters 1-5/8″ (~41mm) — retaining thread 1-3/4″ (~44mm)
Series VII — filters 2″ (~51mm) — retaining thread 2-1/8″ (~54mm)

Different Adapter Attachments

Series adapters to fit different lenses: TLR-style bayonet mount, unthreaded push-on, and threaded styles

Colored filters in Series sizes were available from many manufacturers—both names that will be familiar (like Tiffen) to others that faded away decades ago (like Omag). Some useful black and white filters might be found under unfamiliar, older color designations, such as deep red (formerly designated “A” but now #25), green (formerly G, now #13), and yellow (K2, now #8, or X1, now #11).

Kodak Portra Close-up Attachments

Kodak sold “Portra” close-up lenses in the common Series sizes, in strengths of +1, +2, and +3 diopters; but with non-reflex cameras you need a table of corrections to find the distance for proper focus. It’s nicest to get Porta lenses together with their original yellow Kodak containers, which include the table as a handy decal inside the lid.

Among the other Series oddities you sometimes see are Kodak’s “Telek” attachments: These were lenses with negative diopter powers. While it’s a bit non-intuitive, adding one in front of a lens and then racking its focus outwards has the effect of lengthening its effective focal length—yielding a quick & dirty telephoto lens. (The strongest -4 Telek can almost double the focal length). Unfortunately these are really only practical for cameras offering groundglass focusing, e.g. a Press camera.

Now, for most of my photographic youth, I used Japanese SLR systems, whose manufacturers tried to stick with a single filter diameter across most of their lens lines. For Olympus, it was 49mm; for Canon, 55mm. You just bought a couple of filters in the right size, and were done with it.

But, as my fascination with vintage cameras grew, somehow more and more of them began appearing in my home. And I had a problem—it seemed that each one used a different filter size!

Few Filters, Many Cameras

But this is exactly the situation where the Series system shines. A friend had inherited a garage-ful of assorted series adapters and accessories; and by sifting through his heap, I was able to find adapters for about nine of my favorite vintage camera lenses—allowing me to use a single set of Series VI filters for everything.

Okay, I admit you could approximate the same thing today with one set of (oversized) threaded filters plus an arsenal of different step-up rings. But another advantage of the Series system is that many “slip-on” adapters were sold—making it possible to use accessories even on lenses that have no filter threads. (Or, ones with damaged threads, or impossible-to-find sizes… ) One Kodak 42mm push-on adapter turns out to be a perfect fit on vintage Diana cameras.

Push-on Adapter Fits Odd Cameras

Slip-on Series adapters let you use filters with threadless oddball cameras

Admittedly, one place where this clever scheme falls apart is with polarizing filters. A polarizer needs to be rotated to a particular angle to be most effective, something that wasn’t practical with the Series drop-in disks. (In fact, there were clever threaded polarizing attachments manufactured for the Series system—you looked through a separate auxiliary polarizer while rotating a control handle—but it may be tough finding one today.)

It’s been decades since Series accessories were being widely produced. Yet if you dig around on eBay you will still find sellers offering series adapter rings and drop-in filters. (Note that some listings use Series 6, Series 7, etc., instead of the roman numerals.) Also, some specialist mail-order firms may be able to help.

If you need to track down every little odd Series filter component one at a time, the process might not be worth the effort. But if someday you’re as lucky as I was, and stumble onto some vast forgotten cache of Series accessories, just remember—it’s a neat system that’s still completely useful today.

Classic or Dinosaur?

Since this blog has been known to trumpet the virtues of fifty- or even ninety-year-old camera designs, perhaps a few words are in order about “progress” in photography.

Of course, camera technology has been going through continuous evolution since the get-go. In particular, George Eastman’s flexible roll film ‘Kodak’ of 1888 ignited rapid development in amateur-oriented cameras, a process which has never stopped since.

The overarching trajectory of these changes has been to reduce the number of technical details the photographer needs to keep track of. Today we’ve stopped noticing interlocks that prevent us from accidentally double-exposing or shooting blank frames (until we use a camera without them!) We take for granted light meters which read through the lens, offering accurate exposures without tedious calculations for filter factors or lens extension. Yet at one time, both innovations were much-trumpeted, newfangled breakthroughs.

Digital cameras are just the next chapter in this process, with today’s top models basically being sophisticated small computers—evaluating white balance; weighting light readings from multiple zones; computing the optimum point of focus with moving subjects, etc.

If you are a manufacturer of cameras, you can hardly be blamed for keeping this cycle of innovations churning. Unless consumers have some incentive to replace their older (and presumably still functioning) models, your company simply goes out of business.

Yet the essence of making an image has scarcely changed since the first handheld cameras became available. And at some point all photographers must ask, where is the line when technology and automation start to encroach on our own creative process?

Few of us would want to go back to coating our own collodion wet plates (although there are a few!) Yet controlling focus and exposure for specific effects could be essential to our own specific vision—not a choice to be left to the camera’s electronics. And learning to master those steps manually brings its own pleasures.

Thus, each photographer chooses where to step off the speeding express-train of technological progress, at whatever level of technology feels most comfortable.

For some it’s a 1980s manual-focus SLR with (optional) auto-exposure. For others who need to work quickly, it’s the latest 12-megapixel auto-everything wonder. For an eccentric few, it’s a completely metal, mechanical, 1950s rangefinder requiring a separate light meter (or even—gasp!—guessing the exposure). But this is one reason Silverbased often celebrates camera designs that are well past their 50th birthdays.

In connection with this, it’s interesting to note a few film-camera brands which have attained classic status—models which have spent decades in production, with only a few minor changes to their original design. How can a camera achieve such “rightness” that it remains viable in the marketplace for 50 years or more?

One classic is surely the Hasselblad medium-format SLR. The first model 1600F went on the market in 1948; but problems with its original focal-plane shutter led to the introduction of the 500C in 1957. This modest redesign allowed the use of several excellent Zeiss lenses, each carrying its own individual Compur leaf shutter.

1952 Advertisement, Hasselblad 1600F

Advertisement for Hasselblad 1600F, featuring a Kodak Ektar lens; U.S. Camera, November 1952. Click to view larger

The quality of this lens lineup, and the high level of finish and durability of the Hasselblad body, earned it many admirers and professional users (including Ansel Adams). In later decades, the 500-series went through minor evolutionary changes; but the fundamental design (and in most cases compatibility of the modular accessories) remained faithful to the original—even its lack of an instant-return mirror. While production of the series appears to have finally ceased, new-old-stock 503CW bodies remain available today.

An even more timeless design is the Rolleiflex twin-lens reflex. Rollei used its experience building multi-lensed stereo cameras to introduce the original Rolleiflex in 1929. In 1937 Rollei introduced its crank-winding “Automat” version, introducing the styling and control placement which not only remains unchanged to the present day, but also launched countless TLR imitators.

1956 Advertisement, Rolleiflex 3.5

Detail of Rolleiflex 3.5 advertisement in U.S. Camera, November 1956

The Rolleiflex’s standard Zeiss and Schneider lenses were first-rate. And professionals appreciated that the camera offered fast handling and manageable size, while retaining a large-enough negative to insure good image quality. (Remember that the typical press camera of the mid-20th century shot a 4×5″ negative.)

The popularity of all TLRs nosedived in the 1960s; but the Rolleiflex still had enough strengths (e.g. the freedom from viewfinder blackout) that it has come back into production today—while unmistakably keeping the same design as the 1937 model.

Naturally, no list like this would be complete without some mention of the Leica series of 35mm rangefinder cameras. We must give Leica credit for making the 24×36mm image format universal today, pioneered in their earliest scale-focusing models of the 1920s. Yet the early screw-mount Leicas are more desired today as collector pieces than as daily shooters. It’s really a 1954 Leica model which became the epoch-making classic: the M3.

1954 Advertisement, Leica M3

Leica M3 advertisement from its first year of production; U.S. Camera, December 1954

Bayoneting a lens onto the M3 automatically selects the correct bright frameline, within a viewfinder of legendary clarity. Much faster-handling than its screw-mount ancestors, the M3 became the iconic camera for photojournalists and street photographers. And thereafter (aside from the much-criticized M5) Leitz only made incremental changes to the basic M3 body style. The main evolution has been growing use of electronics (the current M7 offers auto-exposure)—but all later M bodies retain certain quirky M3 features, such as film loading through the camera’s bottom plate.

And for the traditionalist, Leica even provides the mechanical-shuttered model MP, nearly indistinguishable from its offerings of 50 years ago. Leica also has the distinction that its new digital model, the M8, has the clear intent of maintaining as much continuity as possible with the film M bodies, while adapting to current technology.

Lest you accuse me of some Euro-centric bias, there is room in my list of classics for a mention of the landmark Nikon F—a 1959 introduction which set the standard for all quality 35mm SLRs to follow. However Nikon did not shy from doing “blank sheet” redesigns of their professional F series; and the current (and presumably final) F6 model shares little besides the lens mount with its distant ancestor.

1959 Advertisement, Nikon F

Nikon F advertisement from its first year of production; features such as instant-reopen aperture were radical at the time. Modern Photography, September 1959

However, I would single out the Nikon FM2 for “classic” status, particularly the final “n” version. Despite its 1983 introduction date, the FM2n swam vigorously against an industry tidal wave of more electronics, plastics, and automation. In a sturdy, modestly-sized metal body, the FM2n offered a 100% mechanical shutter, simple center-weighted metering, and manual exposure—it’s a direct descendant of Nikon’s 1970s model FM.

Nikon FM2n

Nikon FM2n, creative commons image from Flickr user Qualudez

Yet those old-technology roots were raised to an exquisite level of refinement in the FM2n: Shutter speeds to 1/4000th of a second; flash sync at 1/250th; and of course accepting the enormous range of fine Nikkor lenses. Two decades of Japanese mechanical SLR development reached its pinnacle in the FM2n, whose production continued (in new titanium and commemorative editions) through the turn of the millennium.

What all of these “classics” have in common is a sensible, well-tested control layout; reliability and excellent build quality; and access to top-quality lenses. For photographers who choose to skip entire generational jumps in camera technology, they simply represent the finest models available; and their value scarcely diminishes with time.

Thus their prices on the used market also tend to remain high, relative to other brands—one reason why even at this late date, your humble correspondent does not personally own any of the models mentioned above.

Some alert readers out there may be grumbling that I’ve forgotten another class of film cameras, ones that also enjoyed surprisingly long production runs. Far from the elite models I’ve mentioned here, these were more humble cameras, owing their success to affordable pricing rather than technical refinement.

No, I haven’t forgotten—but those cameras will need to wait for another article