Tuesday, October 10, 2006

From the Archive:
Color Intensifiers: "Better" is the enemy of "Good" by Dr. Nye Simmons

In another article from our archives, Dr. Nye Simmons discusses color and color intensifiers. From around 1996, it predates Singh-Ray's "lighter, brighter" LB Color Intensifier, so we've updated some of the references to reflect this new development, and edited a bit for length and clarity.

The color red. The eye is forcefully drawn to it in the frame. Oriental artists have known this for centuries and used it sparingly as an accent or focal point. Red will dominate a scene, even in small amounts. As the bluish end of the spectrum approaches, the effect becomes less commanding; the emotional response "cools off" and the mood changes. "Warm" is "in." How often have we heard the term "good color" in response to a fall display or a stunning sunset? These aren't "cold" colors we're raving about. While an individual's reaction to color is affected by cultural, gender, aesthetic, and emotional factors, most of us react more favorably to the red end of the rainbow. Photographers, interior decorators, advertisers, and psychiatrists all recognize the powerful effect that color temperature (color, in everyday speak) has on the beholder.

Often these reds, oranges, and yellows in our photos disappoint us and seem less vibrant than the color we remember -- the color that was really there before the chrome betrayed us. (It was, after all, the film's fault, wasn't it?) Something that would jazz up the colors on the warm end of the rainbow seemed like a good idea.

Enter didymium glass.

Tiffen introduced a version, and with their substantial market presence, use of didymium started to catch on, although slowly -- these babies ain't cheap.

Alas, all was not well with didymium glass. While the intense reds and oranges knocked your socks off, and the yellows were often improved, it had significant color cross-over problems (the overall magenta cast taken on by the neutrals, whites, greens, and lighter pastel shades). Many found this objectionable after the novelty had worn off. The Tiffen filter was thinner, which reduced the objectionable cross-over effects, while preserving the intensified effects at the red end of the spectrum. Improved, but with a long way to go, critics felt the results were often garish and surrealistic, with degraded colors on the opposite end of the spectrum, particularly greens. Even proponents freely admitted that proper scene selection was essential for best results.

Subtle, true to life color certainly has its place, but so does bigger than life, more intense than reality, overwhelming color. The problem was how to get it without an unacceptable trade off. Everyone admitted there was room for improvement -- "better" is the enemy of good. Further developments by Dr. Bob Singh whose Singh-Ray filters are well known led to the introduction in late 1995 of the Singh-Ray Color Intensifier. This filter was designed to reduce the problems inherent to didymium. What sort of optical trickery is this? How does one use it to best advantage?

Didymium is a blend of two rare earth elements, praseodymium and neodymium, which have unusual spectrophotometric properties. These elements selectively absorb and transmit various wavelengths of light, i.e. colors. One can only manipulate the formula so much; significant change needed a new recipe which required several years of testing before a satisfactory solution emerged, which ultimately produced the Singh-Ray Color Intensifier.

The effect can be estimated by viewing the scene through the filter, although the actual effect may vary from one film to another (or among digital sensors). The magenta color of the filter itself gives an estimate of the amount of color cast that any neutral or light shades will pick up in the finished image, however this may be more noticeable on film than through the viewfinder. As a general rule, lighter pastel shades of any color reveal enhancer use more than their deeper counterparts. Colors with the farthest to go seem to get the most push; an intense red won't (can't) get much deeper. Here is an idea of what to expect from enhancers in general, and the new Singh-Ray in particular.

At left, no filter. At right, with original Singh-Ray Color Intensifier

Red is where the effect is most pronounced. They are perfect for fall scenics, and can rescue pre- and post-peak scenes where the color is weak. Anytime a hint of red or blush of pink could stand to be stronger, such as alpenglow on distant peaks, sunrise and sunset scenics, wildflowers -- you name it, put on the filter and check it out. Red can only be so red; the more intense hues get proportionately less "pump." A side by side comparison shows slightly less "pump" with the Singh-Ray, but the results are more believable. It might really have been that good and you just missed being there to see it. If the reciprocity characteristics of the film (or digital sensor) in use includes a color shift towards magenta, the filter's effects will be further intensified, with greater crossover in neutral shades.

Orange gets deeper with a slight red shift and yellows get more golden; the effect is usually beneficial. There isn't that much red in the Smokies fall color palette so to be useful for me the filter has to improve this spectrum (which it does). Again, the Singh-Ray renders the most believable colors of the bunch. Enhancers cause aspens in fall color to deepen toward gold. The surrounding colors will determine suitability for "enhancement." If you aren't sure this is desirable, then bracket filtration so you have a choice.

Greens suffer to some degree with all the enhancers I've been able to shoot with. The Singh-Ray Color Intensifier offers less weakening and a more acceptable rendition -- indeed "green preservation" was one of the aims of the new formula. How much green is in the scene, relative to the colors you want to pump up, and how faithful the green has to be in the final image will determine filtration. Shoot both ways if there is any doubt.

Blues, indigos, and violets are less affected; a slight magenta cast will be noticeable in light pale blues, such as an overexposed sky, and will be nearly lost in a polarized sky. Violet picks up a bit of red shift which is usually beneficial. Blues get a bit deeper with the Singh-Ray though the effect is subtle.

Whites take on a variable color cast depending on lighting and brilliance, and how noticeable this is affected by the proportion of white areas to the total scene, and adjacent colors. As placement of the white passes +2 stops from middle gray, the white tends to pick up less crossover, particularly in direct sunlight. A small area of brilliant white at say +2-1/2 or +3 such as distant snow-capped peaks in a wide angle scenic in direct sunlight will take on a negligible cast, and shots with the different filters will be almost indistinguishable on the light box. With soft light on an overcast day and a longer lens, the same peaks clearly show a magenta overtone using an enhancer. The soft white in the "cotton candy" water of long exposures of moving water and the soft white of fluffy cumulus clouds fare similarly. Here the Singh-Ray gives the best results with subtle shifts, quite acceptable compared to an unfiltered control, and difficult to pick out without the unfiltered image for comparison.

Neutral grays, light grays, and "dirty whites" such as birch and aspen bark, as well as light tans readily show the color crossover cast of enhancing filters. The Singh-Ray gives significantly less pollution of the pure neutrals, and thus more leeway for including them in your scene, even if picky photographers will be critiquing the effort. The improved rendition of neutral colors and whites is the strongest feature of Bob Singh's filter. However, I suggest you bracket your filtration on important shots until you learn to anticipate the results.

Tanned skin tones tolerate the Singh-Ray well, with pale "lily white" Caucasian skin getting a bit sunburned. The Tiffen goes too far for my taste. Determine your own tolerance for skin; portraits seem less tolerant than journalistic shots.

To date I have used it extensively on fall color scenics, especially when trying to salvage rusty "past peak" color. Sunrises, sunsets, and alpenglow often get "enhanced" now, particularly if the color is weak to start with. Wildflowers get their turn in spring and early summer. Historical re-enactments (the "Redcoats" were more rusty in color), Mardi Gras, parades, Christmas decorations -- the potential utility of enhancing filters is limited mostly by your imagination. I'm looking forward to a return to the Grand Canyon next year, and you can bet the filter is going along.

Scene selection deserves some thought for best results. A blue sky day with fall colors is pretty foolproof unless there's a lot of light gray wood or rock in the frame, and all the enhancers I know of will give excellent results -- add a polarizer for extra effect. A fall scenic with tree trunks, rocks, clouds or whitewater will be much more satisfactory with the Singh-Ray Color Intensifier. This filter combines well with the Singh-Ray Graduated Neutral Density Filters to give realistic rather than psychedelic skies. A scene with a small amount of red, orange, or yellow, and a lot of greens may not benefit much, or may even degrade. Pastels and lighter shades of red, orange, and yellow get proportionately more punch than deeper more intense shades -- you can after all only get so red. If there is significant light reflecting into the scene from a colored object such as a brick wall, there may be some additional (wanted or not) effect, particularly in the mid tones and neutrals.

Enhancers combine well with other filters, particularly polarizers, but light loss becomes an issue. The Tiffen costs you about 1 stop and the Singh-Ray LB Color Intensifier about 2/3 stops. Check the reciprocity characteristics of your film/sensor for exposure and color compensation -- a magenta shift will get stronger. Used with a graduated neutral density filter, sky rendition will be a function of colors. Gray storm clouds can pick up color, more with the Tiffen enhancing filter and less with the Singh-Ray For critical usage, shoot both ways and choose later on the light box. If the graduated neutral density filter you are using in combo with the enhancer isn't truly "neutral," such as the Cokin graduated gray, an unwanted color shift may result.

I still bracket scenes that are really important to me with and without the enhancer if I have any doubt as to the scene's suitability for enhancement. In almost all cases, I find I prefer the "enhanced" version on the light box, but I do avoid scenes I think are unsuitable, particularly if there is lots of green involved. I have an assortment of enhancers to choose from because my search to solve the color cast problem was never completely solved, but other than comparative shooting the older ones don't find much use anymore. The Tiffen enhancing filter was an improvement in terms of color cast, but it still had significant problems in the highlights, neutrals and greens, so Dr. Bob Singh's developments were of special interest and great delight.

Enhancers aren't for everyone. If you are considering buying one, you have to ask yourself some questions. Do you want or need exact true to life color for personal, philosophic, or editorial reasons? If so then these may not be for you (better put away the Velvia while you're at it.) But if you punch up the colors, who will notice -- or object? Other photographers notice nuances of color that the general public does not, but they will be unlikely customers.

Do you want to intensify colors in a scene so that the final image captures the emotional reaction that prompted you to trip the shutter? Are you shooting for decor, post cards, or calendars where the color has to jump out and grab someone's attention in order to sell? My freelancing experience, and discussion with other freelancers who use enhancers, is that editors like the pumped up color, or at least are not biased against them. What about camera club competitions, where eye catching color may lift an image out of the crowd?

If you have tried a didymium filter before and found it useful, then the Singh-Ray LB Color Intensifier will be a real delight with its improved color rendition. If you have been disappointed with the results from didymium, then the Singh-Ray should be looked at closely, as the objectionable effects are significantly diminished while the desired effect is improved. Without a side by side comparison, even experienced photographers will be hard pressed to notice the manipulation.

1 comment:

John said...

I really appreciated your article on intensifiers. The side by side image was subtle enough I had to really study it. And your title is appropriate, as is your reference to the interplay with other colors with the powerful red. Well written, and informative. Thanks.
John Buck