Soft focus filters, demystified

Diffusion, fog and soft focus filters: How do they differ?

Today’s cameras, lenses and sensors have gotten so good that images can now appear too sharp, almost too perfect. As a result, photographers have sought out ways to achieve softer, more evocative images.

This being the age of digital photography, there has been a shift to software solutions for softening effects, and there is no end of third-party programs and Photoshop techniques to break down an overly-sharp image. Nonetheless, there is an argument to be made for shooting digitally with lens filters from the get-go, because let’s face it, who wants to spend more time in front of a computer screen if you can get the same result, or an even better result, from a filter placed over the camera lens.

Now it can get confusing. The softening filter world has become almost too nuanced, with manufacturers selling so many subtle effects it’s hard to keep it all straight. But if you break it down into the three categories of diffusion, fog, and soft focus the whole panoply of filters will fall into place. Let’s take a look.

Diffusion filters

A diffusion filter is an equal-opportunity softening effect; it breaks down the image regardless of tonal differences. The typical filter has a glass surface whose clarity has been cut down by sandblasting or other mechanical abrasion or scoring. This has the optical effect of diverting incoming light rays to a greater or lesser degree, thus blending fine details. At tonal borders between light and dark, the image will halate, with the light portion bleeding over into the dark portion.

Another approach is to impose a random pattern of opaque pinpoint dots across an otherwise clear glass surface. This breaks up the incoming rays in roughly the same way, without causing halation. i.e., pure softening without the bleeding effect. Keep in mind that black dot diffusion filters cut down the light slightly and thus require a small exposure compensation. 

Because the visual effect of diffusion depends on subject matter, these filters are often offered in graded sets, with the intensity of the effect varying in steps. The idea is to offer a filter that has almost no effect to a filter whose effect is extreme. In my own experience, the filters “in the middle” are going to be your “go-to” filters; for a graded set ranging from 1 to 5, you are most likely to use grades 2 and 3, for example. Inasmuch as the cost of a full set is not minor, this approach makes a lot of sense.

Knowing which grade to use on a particular shot is a knack learned from experience; it’s hard to make clearcut rules. When I shot food for commercial clients, a touch of diffusion with a lower grade was really not noticeable, and added a slight enhancement by cutting the sharp edges of food. For a portrait of an older woman, on the other hand, a stronger grade eliminated small wrinkles in the skin and saved retouching time. For an utmost painterly effect, what I call the “Hallmark card look”, you would choose the highest grades.

You can mimic commercial diffusion filters with any number of improvised home-brew techniques, and yes, smearing vaseline onto a UV filter will diffuse the image. So will wrapping the front of the lens with a plastic bag, held on by a rubber band. I’ve tried many of these things, and offer no critique as long as you get a pleasing result. However, it’s not the same as using a repeatable, tested lens filter from a reputable manufacturer, and gaining knowledge of how they work time and time again with various subjects.

I photographed Beatrice in the studio using a Harrison and Harrison #2 diffusing filter. It breaks up details just slightly, and never intrudes on the image or looks like a focussing error. Halation at the edges is barely visible.

Fog filters

A close cousin to diffusion filters are fog filters. A fog filter is a diffusion filter added to glass that is not clear but infused with a slight white cast. The slight cast eliminates solid blacks in the image and thereby creates the look of an enveloping fog, hence the name. It’s all about the halation rather than the blurring itself. Fog filters are also offered in graded sets of varying intensity but in general their effect starts where diffusion filters leave off. There is no mistaking their effect on the image, so caution is advised and there is no way to undo the effect in post production.

Soft focus filters

Soft focus filters are an attempt to mimic the optical performance of soft focus lenses that were commonplace in the days of film photography and large format cameras. The goal of soft focus filters, and lenses too, is to blend (soften) slight tone differences while not touching areas of the photograph with great tonal difference. In a portrait of a female, for example, a soft focus filter would blend skin tones, minimizing pores and irregularities, but maintain the sharpness of eyelashes and hair.

In landscape work, a soft focus filter would blend sky tones but leave foreground details sharp and well defined.

A true soft focus filter is a lot more involved than simple diffusion and involves proprietary manufacturing technology; the two are not directly comparable. I use the Zeiss Softar in grades 1 and 2 and the design has been licensed to other companies. Cost is higher than the typical diffusion filter because of the optical innovation.

Hear is Beatrice again, only this time photographed with a Zeiss Softer #2 filter. The difference between the diffusion filter and the soft focus filter are subtle in these studio portraits, and may not show up on your screen image.

How to: Lighting up a pool at night

On a recent vacation trip to Aruba, I was fascinated by the underwater lights on the main swimming pool. I knew I could use a time exposure to burn in the filtered lights, but that would have left little detail elsewhere. I had to add some light, and also add visual interest in the form of a model at poolside.

So off I went with a lightweight tripod, a Really Right Stuff travel carbon fiber. I posed my model in the foreground, which was virtually pitch black, and set my Contax G2 for a time exposure, on Fuji Velvia 50 film. To add light, I used a Vivitar 383 flash set on an auto exposure at f/4. The rangefinder on the Contax was useless in the darkness, so I used a manual focus setting of about 20 feet, which was within the range of the flash automatic range. I tripped the shutter and counted off seconds, and within the middle of the exposure I manually fired the flash. I made a series of exposure ranging from a few seconds to about ten seconds, and picked the best result for the picture displayed here. If you look closely, you might notice that the model moved ever so slightly during the time exposure, but still the photograph seemed effective and interesting. 

What has happened to commercial photography?

There is always a danger in longing for the "good old days" of this thing or that, and the world of commercial photography is no exception. Nothing is more tedious than hearing some old wag complaining about the new way of doing things, usually accompanied by no small amount of self-importance, and moral superiority about how things have gone downhill.

So at the risk of falling into precisely this same gripe, I have to ask: what has happened to the technical and artistic standards of commercial photography?

I think the answer has to be that standards have gone down, often to a dreadful degree. It is not uncommon these days to see photographs of products in which significant surfaces are out of focus. It is not uncommon to see photographs in which the critical plane of interest--the front surface of a slice of cake, to take just one example--is not lit well at all, your eye forced into looking at the wrong part of the picture. More generally speaking, it seems that many images of products don't make the products look very good. Indeed, I have seen some food photography in which the food itself looks downright disgusting.

In my many years of shooting products, the above-mentioned flaws would have not only been considered unacceptable, they would have never even shown up in the first place in any studio of modest reputation. The question comes to mind: Why the change in standards? And then the next question: Is there anything we should do about it?

I think the answers to these questions resides in the transition from analog (film) photography to digital photography, from the years 1995 to the present. For the commercial shooter, this a tale of the switch from 4x5 sheet film used in a view camera, to dslr's with small (in comparison) image sensors. I don't think we realized all the unintended consequences of this transition, and the results have often been not so pretty.

Those of us who spent decades laboring under the dark cloths of a view camera, mastering the fine art of swings and tilts, never realized how much technical and creative excellence we were bringing to the apparently trivial job of photographing a simple object on a piece of white paper or other surface. Typically, you would spend minutes, sometimes hours, moving the lens and film standards of the camera, stopping down the lens and testing for image sharpness with a loupe on the ground glass, then taking Polaroid tests for light balance and overall composition.

With a ground glass image measuring 4x5 inches, it was simple enough to examine every square inch of the image, 20 square inches in all, and through a 5X loupe, no image detail would escape your eye. Focus on image surfaces could be controlled at will; using swings and tilts, critical surfaces could be brought tack sharp, and other surfaces deliberately left soft, thereby directing the viewer's eye. Then with the aid of Polaroid proofing film we could establish lighting quality and ratios, again, to any degree of precision and subtlety. In all these efforts, the large ground glass image, seen upside down, made composition a breeze, and it was common to place overlays on the glass itself to cordon off parts of the image that would receive type. All in all, the resulting image was a study in exactitude and precision; nothing was accidental about it.

Now let's spin off into the world of dslr product shooting, and see how much of this precision has been lost. For starters, there can be no comparison between the aerial projected image of the dslr and the ground glass of a view camera. The viewfinder of the dslr is such a chore, such a strain on the eyes. You've got to get your eye right up against it, and make sure the diopter of the optical system matches your own eyes. The image field is tiny compared to the view camera; details are difficult or impossible to see.

But perhaps the biggest impediment to quality with the dslr is the lack of swings and tilts. In writing this, I am putting aside for the time being the use of digital backs on view cameras, as this combination is a different beast altogether; nor am I writing about tilt/shift lenses. These are at best partial solutions.

Lacking swings and tilts, the images off dslr's can only rely on depth of field to control focus. I will not get into a technical treatise about attempting to control focus this way, but the simple optics of the matter is that stopping down is a crude solution compared to the use of swings and tilts. The only real thing you can do is adjust the focus from front to back. As a result, it's impossible to direct the viewer's eye in a deliberate fashion, causing confusion to the viewer. You can see this over and over again in product photography, wherein only the thinest sliver of an image is actually tack sharp, often of focus planes that are not central to the product itself.

For instance, if you are shooting a bowl of soup from an angle, the critical focus plane is the surface of the soup itself; it should be tack sharp from the front of the bowl to the back. With a view camera and a simple tilt, this is achieved easily, even at wide f/stops. With the dslr, the job is impossible, even stopped down as far as the lens will go. And so we are now seeing many images of soup bowls with sharpness in the front, and then falling off to the back, or worse, the other way around. The viewer's eye tries in vain to bring it all in focus. The luminescence of a liquid surface, the smooth gradation of light from an overhead softbox, the sheer tactile sense of the food itself, are all lost; the food just does not look as appetizing.

I've even seen focus and lighting working at cross purposes. The brightest part of an image will be out of focus, with the sharpest part getting too little light. Again, the eye strains to know where to look.

Using a medium format sensor on a view camera, or a tilt/shift lens on a dslr are partial solutions, but only partial solutions. Both lack that ultimate viewing experience of the large format ground glass.

And so, with this new technology, with all the advantages of speed and low cost that it provides, we have seen diminished image quality. I am skeptical that the precision of large format photography will ever return because print media are no longer central to marketing. The images on websites just don't have to be that fine, just good enough. As the years pass, and outlets for ultimate image quality become less and less, no one will care about it any more and the whole visual memory will fade away. Those ultimate view camera still life images will become quaint antiquities, like fine calligraphy. A visual loss, I would say.

Eastman Kodak eulogy

A Photographer writes a eulogy for Eastman Kodak

I think I share the feelings of photographers around the world that there is something incredibly sad about the recent bankruptcy of Eastman Kodak. Companies large and small go out of business every day, it is the way our system works, and for the most part, nobody pays much attention. But this time it’s different. There just seems to be something wrong about it. It almost feels as if an aging patriarch has been taken down, after a long and valiant struggle. We know these things happen, we know nothing lasts forever, but somehow our lives seem diminished by the loss of “the great yellow giant”, a photography company that once stood astride the whole world of images--imperturbable, reliable, ageless.

And it was once so. For roughly a hundred years, an eternity in the business world, the forward march of Kodak was taken as a foregone conclusion. The company seemed unstoppable, indeed was attacked as a predatory menace by government and competitors early on, as George Eastman bought up businesses, drove others out of business, and brought light-sensitive coated materials to every corner of life. By the 1920’s, the simple act of taking a picture, something we take for granted today, emerged as one of the great lifestyle activities for people rich and poor, and Eastman’s huge chemical complex at Kodak Park could not turn out the product fast enough.

By the 1930’s those coating lines in Rochester were rolling out mile after mile of film, printing paper, motion picture film, x-ray and other medical film, not to mention chemicals, cameras themselves, and there did not seem to be any aspect of modern life that was not touched in some way by the miracle of photography.

I got my first taste as a boy of about 11. I was living in a suburban town outside of New York City, where my father had a government job. One day I wandered into a section of the house attic that my parents used for storage; my brother and I slept in a finished section. Buried in that storage section were the components of a darkroom, equipment my father had purchased and used before my brother and I had come along, and the darkroom dismantled. Fifty years later, I can still remember how mysterious and fascinating the pieces seemed to me: the enlarger, the funny orange “safelights”, yellow processing trays (probably Kodak brand), and those brown glass bottles, some still filled with exotic liquids, and wrapped with that familiar yellow Kodak label and logo, for decades (and still) among the most recognizable brand identities.

I was blessed with a father who encouraged me always, so when I asked him about the treasure I had discovered in that dusty attic, he told me what it was used for. When I asked him if I could set up the parts again, and make a darkroom for myself, he agreed to help me out. Before long I stared in amazement as a black and white print emerged from beneath the clear pool of developer liquid, and from that point on the products of Eastman Kodak sealed my destiny. Like so many others, I fell in love with photography. It became my hobby as a boy, and later my profession as a grownup, and now fifty years later, I am mourning the death of the company that got me started.

Anyone who bothers to study the company’s history knows that Kodak was the lengthened shadow of its founder George Eastman, a pretty decent man overall. He is one of America’s least familiar industrialists, largely unstudied and somewhat mysterious, yet it can be said fairly that the company he built changed the world. The only close comparison today might be Steve Jobs or Bill Gates.

By the time I was in high school, and running the photography operation of the 1962 yearbook, Kodak “meant” photography, and as mentioned, it stood astride the entire industry. It seemed unassailable as a business, and functioned as a guiding institution for progress. Its position and dominance were so secure, the company could afford to bestow lavish benefits on its employees, and almost guarantee lifetime employment. The mainstay product of the company, coated film, sold everywhere in the world, and its quality was so high and unchanging that no one, amateur or professional, ever gave it a second thought.

By the time I was solidly earning a living as a commercial photographer, say from about 1980, Kodak was a reliable and trusted friend of the professional photographer. The company maintained a network of technical service representatives who would visit you personally if you asked, and often handed out film samples and generally tried their best to work out problems. Back in Rochester, you could call on various film experts and a library of highly informative technical publications; almost always, Kodak had the answers, and built incredible brand loyalty.

Well before the threat of digital imaging, however, Kodak received its first wound from Japan-based Fuji Film. In professional circles, in commercial work at least, color transparency product was the norm, and it was here that Kodak made a serious misstep. The world of advertising photography had by the 1980’s taken on a rather overheated and glamorous persona, in which film “looks” took on almost as much importance as the subjects of pictures themselves. Built into Kodak’s “DNA” was a feeling that film products should be technically or scientifically “accurate”, and Kodak color transparency film was just that way. It was the legacy of decades of film production and color science. Kodak marketing people did not notice that commercial photography was being taken over by art directors and other creative types who took a much more flamboyant view of how color film should look.

This opened the door for Fuji to step in with films that had a wholly new “look”, perhaps not as accurate color-wise, but which looked enhanced on a light table. It wasn’t long before many advertising professionals switched over to Fuji film, and to the company’s credit, the product was of high quality and an able competitor to Kodak. I have a hunch that we saw then the first signs of a certain Kodak hubris, a corporate attitude that “we know best”, and that the upstart film company from Japan could not possibly be smarter or make a more desirable product. In any case, it took Kodak a number of years to wake up, finally, to the Fuji threat, but by then the brand loyalties had shifted and Kodak was forced to play “catch up”.

I continued to use Kodak product and never switched over to Fuji, but heard stories about Kodak putting pressure on dealers and laboratories, which led to a decline in harmony in Kodak’s customer chain. These were, by 1990, the first storm clouds that would pass over the bright blue “Kodachrome” skies. The company was becoming insular, frozen in a bubble of overconfidence and complacency.

Still, one has to wonder why the company never took seriously the threat of digital imaging. In the mid-1990’s, I was involved in a consulting project with Kodak, having to do with some digital imaging initiatives. A group of us, including a high-level Kodak product manager, sat in an executive conference room high above Rochester at their corporate headquarters. Clocks labelled with the location of Kodak’s many international locations, lined the walls, each showing the correct time in that time zone. At a certain point in the discussion, the product manager made this observation about digital imaging: “How do we stop this thing?”  Twenty years later, I can still remember with astonishment this utter refusal to acknowledge the digital freight train bearing down on Kodak’s future. Kodak was going to hold back digital imaging and that was that.

So it may have been true that by 1995 or thereabouts, the company’s future was doomed. On the one hand it had the imaging market under its complete control, with a product that it made by the mile and sold by the inch, resulting in huge profits that kept the whole machine running smoothly. But on the other hand, this same profit machine started to have a digital wrench thrown into its works, and there was little Kodak management could do about it, or far more ominously, wanted to do about it. 

Really, it has to be asked if there was any way that Kodak could have managed a digital transition. What were they going to do, phase out Kodak Park, with its capital infrastructure going back decades, all of it based on silver halide imaging, and immensely profitable? By what marketing strategy could the company have introduced digital products without simultaneously eating into the market for its analog film products?

Nonetheless, it took 20 years to bring it all down, a testament to the inherent greatness of its film products. George Eastman stumbled onto one of the most durable of industrial products, one that remained viable and modern for 100 years, always improving, and in the process working its way into every corner of modern society.Toward the end, when the company closed down coating lines and destroyed large buildings to get them off the tax rolls, employees and retirees would come to witness the demolition. When the destruction ended, some could be seen openly weeping, as if part of their souls had been taken down. They remembered when the company was strong and good to them.

On some level, an unconscious level for sure, the name Kodak, and the company’s products, are attached to our history, both large and small, from images of space to the snapshots of a newborn baby. Kodak was there for all these events, and this accounts for the odd feeling of grief we feel over its bankruptcy. 

I think it must be a rare thing to have such feelings for a business enterprise. But great enterprises, like great people, eventually meet their end, and life goes on, for better or worse, without them. Still, it does seem a great loss.

--end--

Contents Copyright 2012 by Michael Chiusano