When a smartphone click can capture a moment instantaneously, the appeal of film photography, with its tactile sensations, rich textures, and anticipation of developed prints, seems like a nostalgic echo of a bygone era.
Photography industry marketers have cleverly implanted in the minds of ordinary people the notion that “grain” in a photograph is a great evil that digital cameras are designed to eradicate. Meanwhile, they instill in professionals the idea that the noise produced by the sensors of high-end digital cameras is analogous to the “grain” of film.
Any critical analysis of these advertising slogans immediately reveals the contradiction. Amateurs are persuaded to abandon film in favor of new digital cameras to solve “grain” problems, while the problems of sensor noise are conveniently omitted. Then, after getting hooked on “modern digital technologies,” they’re offered the opportunity to upgrade to a “cooler” camera to get the very same “film grain” they were trying to escape in the first place.
In reality, there is no contradiction; it’s all about cleverly manipulating terminology and hiding the full truth. Let’s delve into the true nature of film grain and digital noise in photography, whether they are beneficial or detrimental, and what to choose when striving to create an artistic portrait: a photo without “grain,” one with simulated “film grain,” or simply a photo taken on film that has “grain” without any imitation.
Understanding the Essence of Film Grain
The concept of “grain” in photography predates digital imaging, and its origins lie in the very nature of film technology. For many, the following explanation may seem like a statement of Captain Obvious. However, it’s crucial to begin with this fundamental concept.
In film photography, the nature of noise is intimately related to the silver halide crystals that are converted to silver granules during development and form the basis of the photosensitive emulsion. When an image is captured on film, the picture is created either by nano- and microcrystals of silver in black-and-white photography or by long molecules of organic dyes in color film photography. These discrete particles are randomly distributed throughout the light-sensitive layer.
In general, the higher the sensitivity of the film, the larger the “grain” particles. In some cases, these particles can grow so large that under magnification (which is essentially what happens when you scan or print an image from film onto photographic paper), you can see this very image structure called “grain” with the naked eye.
Next, I would separate the concept of “grain” for color and black and white photography. The thing is that in color photography, film grain appears not only as a texture of the image, but also as multi-colored dots on the monochrome parts of the image.
Film Grain in Black and White Photography
Without getting into historical details, it’s worth noting that modern black-and-white negative film has been around for over a century and shows no signs of retiring anytime soon. While materials, emulsion quality, and grain size have evolved, new layers have been added, light sensitivity has increased, and new formats have come and gone, the basic principles of black-and-white film remain unchanged. Let’s acknowledge the undeniable fact: the black-and-white silver negative is a classic and a cornerstone of photography.
Black and white film consists of a cellulose base coated with a layer of photographic emulsion. This apparently homogeneous emulsion is composed of individual grains separated by gelatin in which halogen silver is dispersed in the form of submicron to micron sized crystals. Halogen silver is an ionic crystal with positively charged silver ions and negatively charged halogen ions at the nodes of the crystal lattice. It consists of 94-99% silver bromide and 1-6% silver iodide. The photographic emulsion is coated with a protective anti-halation layer, which also prevents the film from curling.
Light’s Interaction with Halogen Silver Crystals
Upon exposure to light with open camera shutter, a portion of the halogen silver crystals in the photo emulsion are activated, creating a latent image within the emulsion. As photons interact with the halogen silver crystals, neutral silver atoms are formed on the surface of these crystals, detaching from the structural components of the ionic crystal. This alters the structure of the emulsion layer.
The intensity of the light exposure determines the number of activated crystals in a particular area of the photographic emulsion. The more light that strikes a specific area of the photosensitive emulsion, the more activated crystals it contains, resulting in a darker area on the film. If a single halogen silver crystal receives enough light during the exposure process, it will be transformed into a visible silver granule during development. From a photographic perspective, this granule represents a small black dot or speck of a particular shape. This process creates a latent (hidden) image on the film.
The Formation of a Latent Image
A single grain with an average size of 1 μm (micrometer) contains approximately 32 billion silver ions. To form a latent image, at least 4 silver atoms must be released on the surface of the grain. During development, the grains with more than 4 silver atoms on their surface undergo a reduction process in which all the silver ions in the grain are converted to atomic silver, facilitated by the electron-donating properties of the developer.
During development, the activated crystals are reduced to metallic silver, causing the emulsion to darken and the latent image to become visible. Consequently, such a grain appears black when viewed through light. If the grain is not exposed to light, the halogenide remains unrecovered. It retains its milky white color and turns into a transparent area during fixation. Grains with fewer silver atoms on their surface will not be developed, but will instead be dissolved and removed from the emulsion when the image is fixed in the fixing bath. In essence, development magnifies the latent image up to 32 billion times.
Film Grain Visibility in Different Tonal Ranges
The total area of “exposed” halides relative to “unexposed” halides determines the semitransparency of a given area unit of the image. The maximum concentration of exposed crystals corresponds to the maximum opacity of the image on the negative film, while the minimum concentration corresponds to the maximum transparency. Between these values are intermediate densities of grain concentration corresponding to varying shades of gray.
Film grain is minimally visible in the brightest highlights and deepest shadows. By comparison, grain is most noticeable in a fairly wide range of mid-tones (due in part to the nature of human perception). Obviously, the higher the local contrast within a given area of the image, the more noticeable the grain. To confirm the complete absence of grain in the shadows, let’s examine the inter-frame space of an unexposed piece of film.
Some landscape photographers still prefer to use film for night or long exposure photography because of the characteristics of film, such as minimal grain in deep shadows. Aside from the fact that digital photography suffers from noise in the shadows, which is amplified by the thermal noise of the sensor during long exposures, film photography does not experience these problems. As a result, we can achieve relatively clean deep shadows, which often make up the majority of the image area in night photography.
Grain is Inherent in Film Photography
Film grain, akin to digital noise, introduces a seemingly “parasitic” structure that visually overlays the photograph. In reality, it’s not superimposed, but an inherent part of the image, because the film itself is made up of grain particles. Let’s take a closer look at the grain of black and white film.
The larger the average size of the crystals, the more sensitive they are to light due to their increased surface area. The size of the crystals determines the ISO speed of the film under the same conditions. Therefore, the higher the sensitivity, the larger the average cross section of silver halide crystals that form the image, and the better the human eye can see it in the final photograph.
Crystal size also determines how much detail we see. We will not see smaller details in the photograph if the size of the details captured on the film is comparable to the size of the crystal. The larger the size of the crystal, the less of the fine details will be visible in the photograph because they will be “covered” by the grain of the film.
Film Grain in Color Photography
The history of color photography is a fascinating subject worthy of a full-length book. Without delving too deeply into the intricacies of its development, it’s worth noting that color film, both negative and reversal, appeared in the mid-1930s in the United States and Germany. While it was being used for filmmaking, its widespread adoption by the general public was still a few decades away. It was not until the second half of the 20th century that color photography became truly accessible to a wider range of professional photographers.
Color film comes in two primary types: color negative and color reversal (diapositive, slide or chromes). The processes involved in color film are analogous to those in black and white film, with the key difference being the presence of three emulsion layers. Each layer is sensitive to a specific portion of the visible light spectrum: red, green, and blue. Additionally, each layer contains a dye that is complementary to its corresponding light spectrum: cyan, magenta, and yellow (CMY). After the restoration of silver around its crystals, dyes are formed, and another step, bleaching, is added to remove the silver from the film.
During color development, the exposed silver halide crystals in each layer are reduced to metallic silver, while the unexposed crystals remain intact. The interaction between the developing agents and the exposed silver crystals produces oxidized products that react with the complementary dyes in each layer. This reaction results in the formation of colored clouds around the developed silver grains.
Next, the bleaching process dissolves the metallic silver grains, leaving behind the colored dye clouds. The final step, fixing, removes the unexposed silver halide crystals and ensures the permanence of the color image. The tonal variations in a color photograph are determined by the density of the colored dye clouds in each layer, which in turn corresponds to the density of the developed silver grains. These dye clouds typically form clusters that are significantly larger than the individual silver halide grains.
Random Crystals in Multilayered Emulsion
Unlike digital images, which are composed of discrete pixels arranged in a grid, the image on film or photographic paper is formed by a multitude of randomly dispersed crystals of varying shapes and sizes, not arranged in a single layer, but occupying the entire thickness of the photoemulsion. To use the analogy of a wall, a film image would not resemble a brick wall, but rather a Mayan temple wall composed of stones of various shapes and sizes. The crystals themselves are quite small, so the eye cannot distinguish the individual crystals that make up the image on photographic paper. However, when printed from a negative, the image is magnified many times and we begin to notice the images of the film crystals – film grain.
The size and distribution of these dye cloud clusters play a critical role in the overall grain structure of the color negative film. Larger and more densely packed clusters contribute to a more noticeable grainy appearance, while smaller and more dispersed clusters result in a finer and smoother grain pattern.
Strictly speaking, visible grain is an inherent limitation of film manufacturing. Print a photo at 36 dpi and you will see a pixelated grid on the print-the “grain” of the digital age, a printing imperfection. So why don’t film manufacturers make film with grains so tiny that they are impossible to detect? The answer lies in the fundamental relationship between grain size and film sensitivity. The smaller the grain, the fewer photons it can capture and the lower the probability that it will be activated under the same exposure parameters. This, in turn, results in lower film speed. At a certain point, it simply makes no sense to reduce the size of the crystals.
Combating noise in film and digital photography
A wise man said: “If violence is inevitable, relax and enjoy it.” This sentiment aptly captures the evolution of the perception of film grain. Initially considered an unavoidable imperfection, a flaw in the photographic process, photographers have come to accept and appreciate the unique aesthetic qualities of film grain. Once considered a bug, it has evolved into a feature. Many photographers still yearn for the nostalgic charm of film grain in today’s age of advanced optics, high-sensitivity sensors, and sophisticated noise reduction software. Like music lovers who appreciate vinyl’s crackle and hiss, photographers find that grain adds authenticity, warmth, texture, and depth to their images.
Just as camera manufacturers and popular RAW converters (Photoshop Lightroom, Capture One, RAWTherapee, DxO PhotoLab) strive to minimize color noise in digital images, film manufacturers have also sought to address this issue in their products. Chromatic noise, perceived by the human eye as a colorful dithering effect, can be distracting and detract from the artistic appeal of an image. As a result, photographers typically focus on minimizing color noise rather than embracing it as an artistic element.
The situation is different in black and white photography. In this context, film grain can be deliberately introduced as an artistic technique. The monochrome nature of black and white images allows for a more subtle and controlled application of grain, adding texture and depth without introducing unwanted color distractions. While film grain can be applied to color photography, it requires careful consideration to avoid introducing color casts or disrupting the overall color balance. Neutral colored grain is usually preferred to preserve the integrity of the original colors.
Grain in Color Positive (Slide) Film
The image formation process in color positive (slide) film is identical to that in the negative process. However, through a process called “second development,” the film is reversed and becomes positive. In essence, positive film differs from negative film in its more complex development process and certain technological characteristics, particularly the absence of an anti-halation layer. For instance, any negative film can be developed as a positive, and vice versa. Such “incorrect” developments are called cross-processes and are used for experiments with color shifts.
A random grain structure is formed in each emulsion layer based on silver halide crystals. For positive films, the process is more complex, and the dyes are different, but the essence of image formation, as we have already mentioned, is exactly the same as in the case of negatives. Due to the randomness of the grain structure, in each individual point of the image, it can manifest as several closely spaced colored grains. This determines the chromatic, or in other words, color noise, which is very similar in nature to noise in digital photography, but manifests to a greater extent in other areas – not in the shadows, but in the middle and light ranges. The grain character of negative and positive film is the same. Accordingly, the conclusions we made above will also apply to slides.
It is quite impossible to directly compare silver halide technology and CCD (charge-coupled device) image acquisition technology because the principles of image formation are very different – no less than inkjet and thermal diffusion printing techniques.
The Impact of Crystal Shape on Film Grain
In addition to crystal size, the shape of the crystals also plays an integral part in film grain appearance. Until the 1980s, film emulsions were thicker and crystals were more voluminous. The images obtained under these conditions correspond to the prevailing aesthetic perception of film grain. In other words, for most people familiar with the concept of film grain, the term “film grain” evokes images taken with traditional emulsions.
In the early 1990s, Kodak introduced a revolutionary new type of emulsion based on so-called “T”-shaped crystals (derived from the word “tabular” – flat). This technology utilizes flatter grains in a thinner emulsion layer.
Thinning the emulsion allowed for several advantages:
- Increased edge sharpness and resolution: reduced light scattering within the emulsion layer and less blurring of black dot contours led to enhanced edge sharpness and resolving power.
- Improved light capture efficiency and wider photographic latitude: the increased light sensitivity of the crystals due to their flat shape resulted in improved light capture efficiency, leading to a wider photographic latitude (tolerance to underexposure). This meant a greater margin for error in exposure without compromising image quality.
While tabular crystals offered several technical advantages, the resulting finer grain was often perceived as less aesthetically pleasing than the coarser and more textured grain of traditional emulsions. This more traditional grain structure was often associated with a sense of nostalgia, authenticity and emotion, qualities that many photographers found desirable.
Recognizing the enduring appeal and continued demand for traditional grain aesthetics, Kodak continued to produce films based on both grain types. This decision allowed photographers to choose between the technical advantages of tabular grain and the artistic charm of traditional grain.
Despite the artistic compromise, T-grain technology proved to be highly successful and was widely adopted by the film industry. Its advantages in edge sharpness, resolving power, and photographic latitude were widely appreciated by photographers. The technology was not only adopted by Kodak, but also licensed to other major film manufacturers such as Fujifilm and Ilford, who incorporated it into their own film products, Kodak T-Max 100, Kodak T-Max 400, Fuji Neopan ACROS 100, Fuji Neopan 100 SS, Fuji Neopan 400 Professional, Fuji Neopan 1600 Professional.
The previously discussed processes of image formation by silver granules are part of the negative photochemical process. This means that the exposure of the crystals and their subsequent development into black silver dots corresponds to the bright areas of the final photograph. Consequently, grain should be most visible in the highlights and completely absent in the deep shadows of film photography.
While the statement that grain should be most visible in the highlights is generally true, there are some nuances to consider. In extremely bright areas, the density of silver halide crystals on the film is so high that they often completely block light during printing. This results in relatively clean highlights on the final black-and-white print. Shadows also tend to be relatively clean because they correspond to unexposed areas of the film where the grain has not developed. Instead of grain, we typically see the emulsion veil, which has a random noise structure but is of a different character and less pronounced.
The most visible “grainy” areas are typically found in the mid-tones and mid-bright areas of the image, especially when the subject is high contrast. This is because grain is most noticeable in areas where there is a significant difference in light intensity. In terms of image capture characteristics, the graininess of T-Grain crystals is quite similar to that of digital sensor. As a result, T-Grain is more similar to digital noise than traditional film grain. In addition, veil noise also has a “flat” character and is more similar in nature to digital noise.
Understanding Digital Noise in Photography
Now, let’s define what we call “digital noise. Digital images have color distortions that appear as colored dots and spots due to the discrete nature of digital representation and the imperfections of the technology. This problem is inherent in every digital camera. Therefore, you can take any image from any camera and try to enlarge it. You will notice these color spots sooner or later. This is “digital noise”. Its visibility depends on the camera’s sensor, the processing algorithm, and the sensitivity set on the camera. This is where the marketing trick “hides”.
What is the trick? Marketing people somehow suggest that digital noise and film graininess are the same. Just as color grain size depends on film manufacturer, processing technology, and sensitivity, digital noise size depends on sensor manufacturer, processing algorithm, and camera sensitivity setting. Moreover, if you look at an image scanned from film, you will notice that the “grain” looks almost the same as digital noise, and at the same sensitivity levels, a photo from almost any digital SLR camera will look less “noisy”.
I can anticipate your bewilderment – where’s the trick here? So, marketers are right across the board: a decent digital camera is better than a film camera, and that dreaded film “grain” is nobody’s friend. We’re overlooking a crucial aspect: in film, “grain” forms the image, serving as the building blocks upon which the image is constructed – in other words, it carries information. Digital noise, on the contrary, carries no information; it distorts information.
Does Film Grain Outshine Digital Noise?
When scanning film, we introduce the digital noise of the scanner into the existing image, and the imperfections of the scanning algorithm distort the grain (those interested can read about anti-aliasing). The result is essentially a digital photograph taken by a scanner.
Therefore, comparing digital noise to color film grain is fundamentally flawed. In essence, we’re comparing a digital image of the original to a digital image of a copy, both taken by different “cameras” using different algorithms. However, when printed, color film grain looks far more pleasing than digital noise of the same intensity. Why is that? It all boils down to the same reason: grain carries information, while noise distorts it. This can be compared to a mosaic. Looking at a mosaic image (think of Catholic churches with mosaic icons) is much more pleasant than looking at the world through shattered glasses, especially when each shard is a different color.
If comparing a scanned color image to a digital camera file is wrong, what kind of “film grain simulation” are we talking about in the case of high-end digital cameras? If color film is scanned with a “real” scanner (e.g. a drum scanner or Nikon Coolscan 9000) and processed with the right algorithms, the distortions introduced during digitization can be minimized.
Of course, we won’t get an image with information-bearing grain, but we will get a digital image with a grain texture overlay that is much more pleasing to the eye than the colored blobs of digital noise. That’s why manufacturers of professional digital cameras use special software algorithms to convert colored spots into tonal structures, which is called “film grain simulation”. Essentially, it’s a way of converting digital noise that’s unpleasant to the eye into noise that’s less noticeable.
Distinguishing Film Grain from Digital Noise
Digital noise and film grain, while both affecting image quality, exhibit distinct characteristics and behaviors. Understanding these differences is crucial for photographers to appreciate the nuances of each medium:
- Digital noise is primarily evident in shadow areas, where the lack of light amplifies the random fluctuations in the sensor’s signal. Film grain, on the other hand, is less noticeable in shadows and becomes more pronounced in mid-tones and highlights.
- On photographic film, black shadows give way to some veiling, similar to digital noise but much less apparent.
- The traditional, aesthetically pleasing (to the trained eye) grain of older film types differs significantly from modern T-Max grain. Interestingly, the grain of T-Max films has a closer resemblance to digital noise, suggesting a convergence between the two media.
- Film grain is inherently chaotic in its distribution, whereas digital noise has a more ordered structure. This fundamental difference in grain structure is a major contributor to the distinct visual characteristics of each material.
- Grain simulations tend to gravitate toward the appearance of digital noise in images intended for display on a monitor. This is because the digital nature of the display environment more closely matches digital noise characteristics.
When it comes to image quality, the debate between film and digital often centers on each medium’s aesthetic and technical merits. While both media have their strengths and weaknesses, photographers can make informed decisions about their capture and processing workflows by understanding the nuances of their performance at different viewing scales and print sizes.
When viewed at high magnification on a monitor, a photo taken with a DSLR camera usually looks better than one scanned from film or a print. This is because the “right” scanners with the “right” algorithms are inaccessible to the average person. Conversely, at lower levels of magnification, which are more common when browsing images on the Internet or viewing personal photo archives, scanned film images tend to hold their own against DSLR images, or even exceed the visual quality of DSLR images. This is because film’s inherent grain tends to blend seamlessly at lower resolutions.
When it comes to printing, compared to the digital noise produced by inexpensive digital cameras, film grain is generally more pleasing to the eye. When viewed at high magnification on a computer screen, or when printed in a digital photo lab, images scanned from film using professional equipment are generally of comparable or even superior quality to those taken with a high-end single-lens reflex (SLR) camera. This is especially true when compared to images from inexpensive digital cameras.
Timeless Aesthetic of Black and White Film for Your Interior
I hope you enjoyed this article on the nature of film grain and digital noise. Want to experience the unique aesthetic of black and white film photography, but don’t have a darkroom or the time to develop your own film? I’m happy to announce that I now offer high quality black and white fine art prints in a variety of sizes created with professional classic medium format film to suit your taste and decor, and I’m always happy to work with you on custom orders. My work is printed on museum grade archival paper using traditional printing techniques or pigment inks to ensure exceptional quality and durability.
