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I have been using filters ever since I first shot Super 8 film with a little Kodak M-22 camera. Just press the funny-looking piece of metal into the top of the camera to drop in (or remove—I can't remember which it was) the Wratten 85 filter that allowed you to use tungsten-balanced film in daylight, and achieve the correct color balance. Over the years, my filter experience has pretty much stayed the same—I use filters to achieve a technically perfect image. Yes, there were some forays into black-and-white photography, using colored filters to control contrast, and creating the occasional in-camera effect. I remember a stunning combination of an orange grad and a purple grad held in front of the lens on a locked-off shot to create an emotionally moving sunset effect, but even when using diffusion filters, it seemed to me that I had a very limited approach to using filters, as if I were somehow missing the point.
I know that filtering the light that reaches the lens has been a powerful tool for the cinematographer, and I was hoping to develop an improved appreciation for optical filters. So, in search of enlightenment for myself and you, the reader, I recently approached Ira Tiffen, sent him a few very specific filter questions, and he was kind enough to answer them. After I received his answers, we spoke for about 50 minutes. I've combined some of his written responses with select sections of our conversation, below.
Ira Tiffen is Vice President of Motion Picture and Television Filters at Schneider Optics, Inc. In 2004, he left the Tiffen Company after more than thirty years of filter innovation, where his work there earned him a Technical Achievement Award from the Academy of Motion Picture Arts and Sciences and a Prime-Time Emmy Award from the National Academy of Television Arts and Sciences. He is the author of the Camera Filters section of the American Cinematographer Manual, as well as an associate member of the American Society of Cinematographers (ASC), and a Fellow of the Society of Motion Picture and Television Engineers (SMPTE).
My questions were focused on filter use in an era when most filter effects seemingly could be replicated in post. Is there really a reason to use filters when photographing and, if so, which filters couldn't be replaced easily? However, as we got deeper into the conversation, what became clear was that looking at filters as being incompatible or unnecessary in the digital age is selling filters short, as well as the images you can create with them.
Steven Gladstone: Since optical filter effects are essentially baked in, isn't it better in this day and age to do the basic filter color effects in post?
"If you used the appropriate filter(s) to help the camera record everything you needed, your post-production task is made much easier, and you can accomplish what otherwise might not have been possible."
Ira Tiffen: There are many variations on this theme. Color, as a category, is generally simpler to digitally simulate than the broad range of diffusion, contrast, and flare-effect filters, although those have their digital counterparts, as well. Effectively applying digital color control does provide some abilities not available with optical filters. Consider, though, that such digital manipulation can cause adverse artifacts, such as increased noise that may be visually objectionable. Optical filters do not add to the noise level in this manner. Filters are an important approach in avoiding such a problem.
If you are not certain of what effect you want to employ, it will help to know that once an optical filter has been used, it may be possible to minimize some of its effect digitally in post, if not completely remove it, depending on the situation. Whether you decide to use a filter upon original capture, or leave the effect to post processing, a lot depends on how confident you may be with setting out in advance with a certain effect in mind. This can help whether you are using digital or optical means of control.
SG: Are there filter effects that can't be replicated in post? If so, what are they?
IT: The answer lies in whether the image characteristics in need of manipulation can be altered effectively in post. Some can, others present challenges, and some of the latter are currently technically insurmountable. One key effect in this last category is the polarizer. Since, in the real world, the light reflecting from the surface of water or a window is partially polarized and the light transmitted through these materials is generally not, the polarizer can selectively filter out the polarized reflections and thus make more visible what is beyond the window or beneath the water surface. Once you are left with only the recorded image to work with, this distinction between reflected and transmitted light no longer exists. You would be hard-pressed to digitally recreate the effect of a polarizer in such situations.
An important point to consider is that with original capture using filters, your source material is the infinite dynamic range and level of detail of the real world. Anything recorded with current technology pales by comparison. Even having 15 to 20 stops of dynamic range doesn’t come close. If the image information, such as shadow or highlight detail is not recorded initially, you will not be able to digitally add it back in afterward. If, on the other hand, you used the appropriate filter(s) to help the camera record everything you needed, your post-production task is made much easier, and you can accomplish what otherwise might not have been possible.
|Straight, No Filter||Sunset Soft Gradient|
I had a few more basic filter questions that Ira Tiffen was patient enough to answer, but through them all, I must admit to feeling as if I were still missing the point. Therefore, rather than have this article be about the types of filters out there and their application, which can be answered by a sales catalog, I feel it is better to share with you his thoughts on why to use a filter, and why there may be a reluctance to commit to using filters, and the benefits of overcoming that reluctance.
IT: … when you're dealing with veteran cameramen, experienced photographers, people who have done this before, they generally have a sense of what they want to do and they have far less trepidation about using filters because they know what they want and they know how to use the filters to get it. However, when you're talking motion imaging, where it used to be very expensive to obtain access to the equipment and to do anything professionally, you had to have years of experience; today, with a modest amount of money you can have your own film studio—everything from production to post production—and when you can do that, you want to do what you can and, yet, getting it right can often require dealing with not knowing what you don't know.
The fact that you can shoot without lights, shoot in natural light, available light, because the cameras are sensitive enough to it to render proper exposure doesn't always mean you should. You need some experience to allow you to say, “Yeah, I think in this scene, to get the emotional content we want, we are going to diffuse it a certain amount in a certain way, and have it look like this, and to do that we are going to use a filter.” What they (filmmakers) may prefer to do, when they don't have the experience to say that, is to shoot it clean, leave their options open as much as possible and experiment afterwards in post. But that takes time, and that means that you are limiting yourself, whatever you're going to do, to working with what you’ve recorded. This issue is important, because there is no camera out there today that has the ability to capture all that there is in the real world. 15-to-20 stops of dynamic range, even 30 stops of dynamic range pales in comparison to what the real world can dish out. So, if you want to give yourself maximum latitude for creative alteration and manipulation, you want to do it when you are originally recording—and that takes experience. It takes some knowledge and it may be more difficult for the people who don't have it because they were able to graduate to being a cameraman or a producer/director much faster than it used to take without the requisite experience—they’re going to have a harder time. But one of my goals is to help people understand what optical effects can do for you, so that it becomes easier to relate to how filters can work toward the end result as they can be applied to any given production, so as to get the most emotional content and impact into your images.
Twilight Soft Gradient
We began to discuss using and removing effects filters, such as streak filters, which though interesting from a technical standpoint, only highlights another issue with filter use today, one of perception of the purpose of filters, which seems to have morphed into a physical version of an After Effects filter to be tried and removed and, if not removable, then discarded for more flexibility in post. However, giving your filtration choices as much thought as lens, camera, and lighting choices will benefit you more than the equivalent of throwing spaghetti against a wall to see if it sticks.
"The images will work, but in my estimation they won't work as well or as effectively or as powerfully as they would with filters."
IT: …is it our goal here to discuss and focus in on whether or not filters are removable or is it really a question of what is the best way to get the best image, and can you do it with confidence once you understand how the tools work? So that if you go into every creative choice with the query, “Hmm, if I don't like it can I get rid of it,” you wouldn't do anything. Think about it, you've got to decide up front what focal length to use, where to position the camera, what exposure, what you are going to light with and how, and what the ratios are going to be, and all of that. What's your depth of field going to be? How close do you want to be to the subject? What's going to be in the background? What's your composition going to be like? All of that has to be nailed down in the beginning when you’re recording.
So it shouldn’t be a big deal when you’re doing that to say, “I want to soften this image; I want to create a soft romantic glow; I want to also produce a reduction in contrast that lightens the shadow and lets us see a little bit more into it. And to do that I will use a Black Frost one-eighth and it’s going to do all of those things.” There can be a significant level of anxiety over whether you can remove filter effects when you can't do that with virtually anything else. But, on the other hand, I also acknowledge often in my filter talks that you can make movies without filters, you can make commercials without filters. They (the images) will work, but in my estimation they won't work as well or as effectively or as powerfully as they would with filters. As a filter manufacturer you'd expect me to be biased, but this is not just my understanding, it is also that of many others—that’s why we sell so many of these (filters). You're limiting yourself if you don't use filters, but you need to have lights and cameras and camera support and all of that, so you learn about those things first—that's what they teach you in school.
Down the road, if there is time, if there's justification, some people might get some exposure to filters. And many people learn how to use certain filters that they find work for their earlier jobs, and then they stick with those because they have experience with them, and they may be less likely to experiment because filters aren't easy to get, you have to rent them or buy them; there's lots of different kinds. I acknowledge it’s not such a simple thing for most people to gain the requisite knowledge and experience with filters to make them confident enough to say, “Yeah, this is the one I'm going to use for this scene because I know how it works and I know the effect it's going to give me and I know that is the effect I want. A lot of people can't yet make those statements. I think that it is on the part of B&H and on the part of Schneider and others to help our customers with the understanding that will allow them to answer those questions. What am I doing? How do I take what I have and go where I want to go? And what is it going to take to make that happen?
SG: Now digital media is so affordable, it is kind of silly to think that if you’re going to shoot a project, why not test—and I mean besides the difficulty of renting or borrowing a set of filters there’s certainly no reason NOT to test—and get experience with filters?
|Combination Sunset and Twilight Lightened||Combination Sunset and Twilight|
IT: Well, that's my belief. There are plenty of reasons to use filters because they can easily do things that make images so powerful. I often use an example in my talks of something that occurred early on in my years of almost a decade of teaching at the Maine Cinematography workshops. We had a class that was shooting a scene at night. A man walks into a living room that is lit by a couple of interior lights; he walks in the front door, closes it, and walks past a sofa. And once he passes the sofa, and it’s behind him, a sinister figure rises from behind the sofa holding a gleaming knife. Now we shot that scene through about a dozen different filters, looking for what would give us the best effect. And what was remarkable to me was there was one—one such filter—one such effect that everyone unanimously decided had created a look of such imminent evil on that gleam that none of the other filters was able to match. It changed the power of that scene. What was it?
Oddly enough, it was not the “evil gleam on a knife filter.” It was instead a black net, which was a net mesh designed to make actors look good, have skin that was more flawless and look more star-like, because nets have been used since the ’Thirties by cinematographers for that very purpose. So it was really designed to make women, especially, look their best. It was a cosmetic control filter. And yet it was the one filter that everyone in the group—some thirty-odd people watching this—unanimously decided was far and away the most effective “evil glint on a knife” effect from all the other things that we tried. Now you could not have figured that one out without having tried it, and if you hadn't used the filter, you would not be getting the maximum impact out of your image. And yet it is such a subtle thing because, bear in mind, absolutely everything else about that scene was otherwise unchanged from one filter to the next, and when compared to the un-filtered scene. The only thing that made all the difference was the use of the filter. So if you have filters available, if you have the right ones, if you know what the right ones are and how to use them, and if you have an idea of what you want something to look like and how to get it to look like that, you're going to be ahead of the game, and ahead of your competition as a cameraman.
What I gained from the conversation was that optical filters are just as valuable a tool in today's digital environment as they were before the digital explosion gave everyone with a computer and inexpensive software the ability to manipulate their images after recording them. As with any tool, the more practice you have, the more comfortable and effective you will be with it. Optical filters can help you get the most out of your images, from balancing exposure to adding an emotional impact; optical filters are too powerful a tool to be left unexplored and misunderstood.