Color Balance in Film Is Not a Creative Choice 

The basic five-color palette extract for Kodak film stocks from Lomography.com public images collection. Note strange looking palette for the most common, most used movie stock Kodak VISION 500T.  

The relative intensities of red, gree, blue components in a light from different sources. Illustration by author. 

This is where things become more interesting, and where a bit more nuance is needed.
When we talk about color film, it helps to clearly distinguish between two types of stocks: slide film and negative film.

Let’s be Transparent About Slides and Negatives

At first glance, these two types seem very similar. Both rely on the same basic idea: three light-sensitive layers responding to red, green, and blue light. In both cases, the film records those signals at the moment of exposure. The obvious difference is what you get at the end — either a ready-to-view transparency, or a negative that still needs another step before you can see the picture.

What actually defines the final form of the image is the chemical process used to develop the film. Slide films are developed using a so-called reversal process (most commonly E-6), while color negative films use C-41 or, in the case of most motion-picture stocks, ECN-2. You don’t need to know the details of these processes yet, but if you’ve heard these names before, they serve as useful mental reference points.

At a deeper level, slide and negative films do differ in many ways. Still, to emphasize how closely related they are, it’s worth noting that you can develop slide film in a negative-film process and still get an image to appear — albeit a very poor one. That alone shows that the basic recording mechanism is similar, even if the intended use is not.
What matters most for us is this: once slide film is processed, it is the final image. Nothing can be adjusted afterward. What you see on the film is exactly what was recorded at the moment of exposure. When a slide is projected onto a big screen — as it was meant to be — that image is complete and fixed.

The Joy of Slides

In fact, this exact property is what makes slide film so enjoyable — and so hard to replace. Light is recorded and played back with remarkable fidelity, often with a richness of color that even the best computer displays or laser projectors struggle to reproduce.
At the same time, when the balance between red, green, and blue changes, slide film records those color shifts with scientific precision. When the light is no longer midday sun but a cloudy sky, the image turns cooler and bluer (because that kind of light contains proportionally more blue than direct sunlight). When the scene is lit by incandescent or halogen lamps, colors shift strongly toward warm oranges. Nothing is compensated for at the film level.
In many cases, photographers deliberately use these shifts to create a specific mood or narrative. Strategic use of mixed light — daylight and tungsten illuminating different parts of a scene — can produce extremely impressive and colorful images. But if the goal is simply to record the scene the way your eyes perceive it, those shifts become a problem. Under artificial light, that goal is impossible to reach with slide film unless you -photographer — take very deliberate compensating steps during the exposure (more on that later).

When Two Negatives Make A Positive

Now, if the medium is color negative film, the recording of light is essentially the same as with slide film — remember, the films themselves are constructed in very similar ways. The key difference appears later. When working with negative film, the photographer has access to a powerful color-correction tool: the enlarger, or today, the scanner (though we’ll avoid stepping into the digital realm here to keep things strictly analog).

Because the negative is not the final image, many color shifts that would be unavoidable on slide film can be corrected during printing. This gives the photographer much more freedom. They can decide how closely the final image should reflect the character of the original light, or how much that character should be blunted or exaggerated.

But there are natural limits to what can be corrected. The most pleasing color images come from film, where all three color layers end up with roughly similar strength (what we call density). That balance is not accidental. As discussed earlier, the layer sensitivities are designed around the typical ratios of red, green, and blue light in the illumination.
The next image illustrates the difference between daylight and artificial halogen or tungsten light.

Under normal sunlight, the ratio is close enough to 1:1:1 that all three color layers can work comfortably together. Under halogen or incandescent light — which still appears white to our eyes — the balance shifts strongly toward something closer to 4:2:1, with much less blue present.

Both slide film and negative film will still record the scene faithfully to the best of their ability. But when that image is presented to a human viewer, the imbalance becomes hard to accept. The slide appears overwhelmingly warm, often dominated by orange and yellow tones.

As noted earlier, negative film does allow some correction during printing, but that correction has clear physical limits. Large imbalances between layers mean that pushing the image back toward neutrality often leads to clipped highlights, blocked shadows, or weak color separation. Unless the scene has very low contrast, the result is usually compromised.

Bluer White and Redder White Walk Onto a Movie Set

From a historical perspective, it was the need to get rid of very hot, very expensive, and very noisy (!)— though sunlight-like — carbon arc lights that pushed Technicolor, around 1950, to introduce a new system designed for low-level, unfiltered incandescent lighting. This shift allowed movie sets to quite literally cool down, since carbon arc lights produced immense amounts of heat.

This move had nothing to do with the notion of color temperature. Color temperature is simply a shorthand for the spectral composition of light emitted by very hot metals or gases. A value of 3,200 K corresponds to the filament temperature of a bright incandescent lamp. Halogen lamps typically operate with filament temperatures slightly higher than standard tungsten, often around 3,400 K. To the human eye, this light appears bright and white — but from the film’s perspective, it is still significantly redder than sunlight.

With that in mind, the term tungsten-balanced (3,200 K) just tells you that this film expects red-heavy tungsten or halogen light, not the bluer balance of daylight.

So, for example, an ISO 100 color film might have its blue-sensitive layer behaving more like ISO 400, the green layer like ISO 200, and the red layer like ISO 100. Under red-rich, blue-deficient halogen light, that design allows all three layers to record light within the useful range of their characteristic curves. After processing, the image matches how our eyes — adapted to tungsten light — would experience the scene.

Let’s pause and summarize

Film stocks record light directly and scientifically. They do not adapt like the human eye. Because of this, we need different film stocks for different kinds of light. We have daylight-balanced film for roughly 5,500 K sunlight, and tungsten-balanced film for roughly 3,200 K artificial light — each designed to produce colors that feel natural to us under their intended conditions.

Slide film follows a strict rule: what the film sees is what you get. Negative film records light just as honestly, but allows for some correction during printing. Large mismatches between film and light, however, still cause unacceptable color shifts in the final image.

As a historical aside, there have been attempts at compromise. One example is the consumer-grade ORWO NC21 from the 1980s, balanced around 4,000 K. With skilled printing, it could produce decent results under artificial light, flash, or daylight — with the help of an experienced master printer.

Compilation by author from public galleries on Lomography.com 

So now let’s look closely at the reference image placed at the beginning of the article. We all know the excellent Kodak VISION3 500T film stock, widely used in movie production on sound stages under artificial light. But when it makes its way to photographers — either as bootleg hand-spooled rolls or as remjet-less CineStill 800T — it often appears in online galleries as bluish and, frankly, not very inspiring. You can see this clearly by comparing the five-color palettes shown above the images side by side.

In Real Life vs. In Post

So why does this stock become a trap for so many people? Most often, it comes down to a persistent — and rather poisonous — notion that in our digital age everything can be “fixed in post.”

Personally, I find it hard to understand why someone would choose to shoot film only to subject it to heavy, Frankenstein-style surgery on a computer afterward. Film excels precisely where digital still struggles. Shooting film and then undoing, in post-processing, what film does best feels like a strange trade-off. But I digress.

So it appears to be a common pattern: people buy tungsten-balanced film like Kodak VISION3 500T or its derivative, CineStill 800T, without a clear plan for when and how to shoot it.

The funny thing is, it’s not that hard to effectively convert this stock into a daylight-friendly film. In the same way, it’s also possible to make VISION3 250D behave comfortably under tungsten light. What you cannot do is turn either of these stocks into something that truly loves fluorescent or low-CRI LED lighting — but that’s a different story.

So what’s the trick?

The solution is to modify the light before it reaches the film. Widely available color-conversion filters do exactly that. Below is just a small sampling from B&H, but many manufacturers offer equivalent filters. 

Wratten filters are widely available and can compensate for almost any difference film type and lighting type as long as those differences can be expressed in Kelvins. A bit unusual, but works well because that’s just a physics. 

A warming filter like an Wratten 85 removes excess blue light from daylight, making it suitable for tungsten-balanced film. A cooling filter like an Wratten 80A removes excess red from tungsten light, making it suitable for daylight-balanced film. You do lose some light in the process — typically one to two stops — so the film becomes effectively less sensitive. That is a small price to pay for letting the film work the way it was designed to.

It’s important to note that these filters are not special effects. They are part of exposure, just like ISO or aperture. Used this way, color fidelity stops feeling like luck and starts feeling predictable. In many cases, the same correction is applied with colored gels placed on the light sources instead of on the lens — this is standard practice in motion-picture production. Filters and gels also come in different strengths, allowing fine-tuned color correction when needed. For more complex scenes with mixed illumination, a portable color meter can analyze the light and recommend the exact filter required for a given film stock.

Of course, we are steadily moving into a world where tungsten lamps barely exist anymore. Indoors, they have been replaced by various LED sources; outdoors, by sodium and other discharge lights. That’s a separate problem — and a harder one.

So this is a fairly simple, fundamentally analog solution that can fix most of those blues and oranges. With the right filters, you can shoot all day under daylight or under halogen/tungsten light and let the film behave as intended.

These filters don’t take the joy out of film photography. They give you control and confidence at the moment of exposure — something no amount of computer work afterward can truly replace.

Optional addendum — can be skipped on first reading

You might reasonably ask why we don’t need separate digital cameras for daylight and tungsten light. The answer is simple: while a digital camera also breaks incoming light into red, green, and blue channels, it can do math.

Because the usable sensitivity range of a digital sensor far exceeds that of silver-based film layers, the camera can apply numerical multipliers — often in the range of 1× to 5× — to each RGB channel. With that, white balance is corrected automatically and invisibly to the photographer. And if you shoot RAW, you can change that balance later, as many times as you like, without penalty.

That flexibility, however, belongs to the digital world. It sits outside the strictly analog story we’re telling here.