by Ira Tiffen
Ever imagine how nice it would be if you could get optical filters custom made to your unique specifications, have almost immediate delivery right to your location, and at a price that would fit any production budget? Well, stop imagining, because, if the situation is right, you can. Here’s how…
It’s been years since I heard Robert Farber, the noted photographer, talk about his method for creating a ‘light-ray’ flare, especially in certain instances when nothing else would work. He rubbed his nose to place skin oil on the tip of his finger and applied it carefully to the surface of a clear filter. Knowing how to align the pattern he placed on the glass, he could stream light flares in almost any direction and in any location within his image. And he could do this in minutes to match the need of the moment.
The accompanying images show how this can be useful: A dead-end street at night, eerily illuminated by a lone streetlamp; all is quiet. Without warning, the lamp flares into a glowing orb, a single ray of intense light reaching out ominously toward the street below.
You could do this sort of thing later with CGI. But with a bit of patience, trial-and-error methods can have you finding just the right pattern to create your effect while still on location. The trick lies in understanding the way the pattern you make causes the light to change direction and, for situations that require it, how to make a change in the effect over time.
Our other example is that of the sun peeking through dense clouds. Here, we create two light flares streaming down at an angle from above, along with an overall glow surrounding the break in the cloud cover. The effect makes for multiple interpretations, any one of which can be supportive of an element in your story.
The basic technique used in both examples recognizes that, much like star effect filters, the flare lines extend outward from the light source in a direction that is perpendicular to the direction of the lines in the pattern on the filter; vertically oriented pattern lines make horizontally oriented flare lines.
What you’ll find is that some time spent playing around with this technique BEFORE you need it will teach you a lot and make your on-location time more productive. Practice with a clear bulb, or something that might more closely approximate the type of light you will be using, and use a darkened room or at least a dark background. This will let you see best what you are doing. Then get your filters, put some skin oil on your finger, and start ‘painting.’
Begin with making straight lines, rubbing either back and forth or in only one direction (lifting up at the end and then starting at the beginning again). Each method will have its effect on the result. Straight lines in the pattern will tend to make straight light flares. The idea is to make a pattern that, while you can see it and see the resulting light flare, is not going to appear too ‘frosted’ for your image. If it does, you can tone it down by rubbing lightly over the pattern with a clean cloth or tissue. Micro fiber lens cleaning cloth works well, but you could use almost anything safe for the filter surface. You will also do this to remove excess oil from parts of the filter you want to remain clear.
Once you have begun creating even the simplest pattern, look through it at the light, holding it close to your eye; move it around, and see what it does. Make alterations and check for differences in effect. Also, remember that the lens will see it yet differently, so using an appropriate camera, make recordings of the effects and take notes on what you did to accomplish each one. Bear in mind that differences in brightness levels between the light and its (expectedly darker) background, lens focal lengths, distance to the light from the camera, and other, similar variables will all contribute to the final result.
Also, small changes in positioning the filter relative to the light will make potentially large changes in the effect. This requires care, and is also a consideration when panning and tilting. This allows for a certain ability to ‘animate’ the effect. If you use a filter that can be reliably and consistently positioned, as in a matte box, you will find that sliding or rotating can produce intriguing effects. If your filter is sufficiently larger than the area you are imaging through, you can move from the clear part of the filter to the effect part, which is how I did the lamppost above, and how you would introduce the effect in motion imaging.
Try making patterns that are swirling or circular. They will cause light to emanate out in many directions. You can mix patterns to produce multiple effects; straight lines in various directions as well as an overall ‘glow.’ This is how I created the effects in both of my examples here.
An important note: you may find this technique an invaluable alternative for creating dramatic light rays when artificial fog isn’t possible or other atmospheric haze available.
Options: Use a larger-than-usual filter, or if optically acceptable for the situation, a piece of clear window glass (try float-quality in a thickness between 0.090” and 0.125”) and maintain clear space for before and/or after the effect, and for perhaps multiple positions for different effects to happen consecutively.
It will be hard to choreograph these changes successfully without sufficient care in the positioning, but anything is possible. You may find it helpful to ‘calibrate’ the filter at its edge, making markings you can use to help position the filter appropriately.
You can apply the effect to the surface of another effect or color filter, for simple combination effects. When an effect has been used, it is easy enough to clean the filter and create a new one for another situation. However, you may also find you want to keep it for re-use. Store and transport it in a suitable container that doesn’t contact the patterned surface; sometimes a simple paper envelope is all you need here. You can also use other materials than skin oil, like Vaseline or even clear (or transparently colored) nail polish; once dry, the latter makes for more permanent patterns.
Whatever you do, develop a means of replicating the effect reliably, using either traditional or custom-made mounting methods. With these considerations in mind, you will be most likely to get what you want when you want it. Given the longstanding notion that when looking for a combination of good quality, price, and delivery, you generally settle for getting just two, you now have something that can, under the right circumstances, truly deliver on all three.
In over 30 years of making optical filters, Ira Tiffen created the Pro-Mist, Soft/FX, Ultra Contrast, Glimmerglass, and others, netting him both a Technical Achievement Award from the Academy of Motion Picture Arts and Sciences and a Prime-Time Emmy Award. Elected a Fellow of the SMPTE in 2002, he is also an Associate Member of the ASC, and the author of the filter section of the American Cinematographer Manual.
