aperture

MORE DEPTH WITH THE PHOTOGRAPHY EXPOSURE TRIANGLE

Andrew Shu · 16 August 2021 · Leave a Comment

In the previous article, “The Three Most Basics A Beginner Photographer Should Know”, there are graphics and explanations on Aperture, Shutter Speed, and Film Speed/ISO scale. In this article, I would like to share more depth about them. All three are represented by numbers. In the photography world, the interval from one number to another is called a “stop.” Either stop up (increment) or stop down (decrement) — for example, an Aperture of f/5.6 to f/4 is one stop up, and f/5.6 to f/8 is one stop down. The same applies to Shutter Speed and Film Speed/ISO. Shutter Speed from 1/125 to 1/250 is one stop up, and 1/125 to 1/60 is one stop down. For Film Speed/ISO, 200 to 100 is one stop down, and 200 to 400 is one stop up. Just to avoid confusion, “up” and “down” refer to the [amount, time, and sensitivity] of light going into the film plane [in film photography] or digital sensor [in digital photography], not the numbers themselves.

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There are terms in film photography: push and pull. The term “push” is used when taking pictures using ISO 400, but the camera is set to ISO 800, known as “push one stop.” The reverse situation is when ISO 400 is set as ISO 200, aka “pull one stop.”

Why did old-school photographers push or pull the Film Speed? A couple of reasons, from my experience: sometimes photographers, during an important moment, ran out of the preferred film stock. The only film stock available was ISO 400, while the shooting took place at a music concert where the light was low and inconsistent. The ideal ISO for that situation might have been ISO 1600. So, the photographer set (pushed) the ISO to 1600 in the camera while using ISO 400.

During development, the photographer or the lab developed the film for ISO 1600. The result: the film developed at ISO 1600 produces more noise, maybe a bit more than true ISO 1600. However, the result gave an artistic feeling — that’s another reason photographers sometimes pushed film.

Although in all three (Aperture, Shutter Speed, and Film Speed/ISO), if we look closely, each number to the second next number is exactly a doubled multiplication. In the most common lenses, the biggest aperture is f/1.4, which stands next to f/2, and the following number is f/2.8, which is exactly f/1.4 times two. The number f/2.8 stands next to f/4, and the next after f/4 is f/5.6, which is exactly f/2.8 times two. Do you get the idea?

manual-lens-with-aperture-settings — Manual Focus Lens

In digital photography, the Aperture has more increments and decrements than in film photography. Thanks to technological advancements, digital cameras (DSLRs) have increments up to 1/4 stop. Not only does the Aperture have more increments in stops, but Shutter Speed and Film Speed/ISO do as well. All of these offer more creative freedom to photographers to explore the making of stunning photos. Not all DSLRs are created equal; some have more capabilities than others. However, the basic principles are the same across the platform.In digital photography, the Aperture has more increments and decrements than in film photography. Thanks to technology advancements, digital cameras (DSLRs) have increments up to 1/4 stop. Not only the Aperture has more increments in stops, Shutter Speed and Film Speed/ISO have them as well. All offer more creative freedom to photographers to explore the making of stunning photos. Not all DSLRs is created equal, some have more capabilities beyond others, however, the basic principles are the same across the platform.

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CALIBRATING THE EXPOSURE READINGS

As I mentioned earlier, the three basics (Aperture, Shutter Speed, and Film Speed/ISO) must correspond in conjunction to achieve proper exposure. Before setting the Shutter Speed or Aperture, the Film Speed/ISO must be preset, and the White Balance must be assigned for a DSLR.

For example, when taking pictures outdoors in daylight, ISO 100 is advisable. White Balance can be set to either Auto White Balance (AWB) or Daylight. When using the Daylight setting, always remember to check it if the location changes—such as moving from indoors to outdoors, or in cloudy or nighttime conditions. Occasionally, I forget to change the White Balance when changing locations. Although I can correct it later when shooting in RAW using software such as Adobe Camera RAW or Adobe Lightroom, I usually set my White Balance to AWB. From my experience, Auto White Balance is not entirely accurate, but it is still preferable to setting it to Tungsten while shooting in daylight.

Note: RAW file acronyms include CRW or CR2 for Canon, NEF for Nikon, ARW for Sony, RAF for Fuji, etc.

White Balance settings in nearly all DSLR cameras are virtually similar, with minor variations: AWB (Auto White Balance), Daylight (5600K), Shadow/Shade (7000K), Cloudy (6000K), Tungsten (3200K), Fluorescent (4000K), Flash (5500K), and Custom White Balance (where you set your own reference point). By convention, Kelvin (K) is used to measure color temperature in photography. Daylight is typically between 5000K and 5600K, where white appears truly white.

As I mentioned in the article “The Three Most Basics A Beginner Photographer Should Know” film cameras do not have a white balance feature. In film photography, white balance is determined by the type of film used. Digital cameras, on the other hand, use image sensors similar to video cameras, and the white balance feature helps to balance colors and grayscale accurately.

While some may argue that white balance settings are less critical today—since modern photo software allows adjustments in post-processing—it remains a helpful tool. It’s also worth noting that Auto White Balance (AWB) can vary between camera brands, as each manufacturer uses slightly different algorithms to compensate for ambient light.

SHUTTER SPEED PRIORITY

Once the ISO and White Balance are set, I move on to choosing between Aperture or Shutter Speed, depending on what I want to shoot. For example, when photographing my kids outdoors and I want to ensure they are always in focus during their activities, I select Shutter Speed Priority (“Tv” on Canon cameras, “S” on Nikon, Sony, and others). Choosing Shutter Speed Priority guarantees that my shots maintain focus.

What Shutter Speed should I set? For most outdoor action, 1/125s usually suffices, but I increase the speed if my kids suddenly move like “Flash” or “Superman.”

It’s important to note that lens focal length affects the required Shutter Speed. The longer the focal length, the faster the Shutter Speed needed to prevent camera shake when shooting handheld. Unless using a tripod, the Shutter Speed should generally be no slower than the lens focal length. For example, with a 105mm lens, the minimum Shutter Speed should be 1/105s or faster. This guideline, known as the reciprocity rule between shutter speed and focal length, is widely practiced to maintain sharp handheld images.

After selecting Shutter Speed Priority, the Aperture automatically adjusts to achieve correct exposure. Conversely, in Aperture Priority, the Shutter Speed adjusts to maintain the proper exposure (Exposure Meter at “0”).

Let’s explore a hypothetical practice scenario using tables below to demonstrate how these settings interact:

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When using Shutter Speed Priority (Tv), any change in the Shutter Speed automatically adjusts the Aperture to maintain proper exposure. For example:

Tv 1/125s → Aperture f/8
Tv 1/60s → Aperture f/11
Tv 1/250s → Aperture f/5.6

The same principle applies when using Aperture Priority (Av or A): changing the Aperture will automatically adjust the Shutter Speed to achieve the correct exposure.

Understanding this relationship is essential when learning Full Manual mode, where both Shutter Speed and Aperture are set manually. In manual mode, always keep an eye on the exposure meter (EXP) at “0”) to ensure the image is correctly exposed.

APERTURE PRIORITY

In Aperture Priority (Av or A), the Shutter Speed automatically adjusts to achieve proper exposure based on the chosen Aperture and the set ISO (Film Speed). The main reason for using Aperture Priority is to control depth of field and regulate how much light enters the camera to properly expose the image.

A larger aperture (smaller f-number) produces a shallow depth of field, making the subject stand out sharply against a blurred foreground and background.
A smaller aperture (larger f-number) increases the depth of field, keeping more of the scene in focus.

Prime lenses generally achieve wider maximum apertures than zoom lenses, giving photographers greater flexibility for shallow depth-of-field effects and low-light shooting.

aperture-1.8-shutter-speed-1/500 — Shallow depth of field

aperture-22-shutter-speed-0.3 — Deep depth of field

Setting Aperture Priority means switching the camera dial to “A” (or “Av” on some brands). When you adjust the Aperture to achieve your desired depth of field, the camera automatically changes the Shutter Speed to maintain proper exposure.

For example:

If the Aperture is set to f/5.6, the Shutter Speed might adjust to 1/60 sec.

If you open the Aperture by 2 stops to f/2.8, the Shutter Speed will automatically increase by 2 stops to 1/250 sec, keeping the exposure balanced.

FULLY MANUAL MODE

There was a time when I questioned why I should use full manual mode when I could just prioritize one setting. It’s true that full manual mode can slow you down compared to Aperture or Shutter Speed Priority, since you must control both settings yourself. For time-sensitive situations, like documenting an important event, priority modes are often more practical.

However, full manual mode gives you complete creative control. It prevents the camera from misreading subjects with unusual contrast or exposure, and it allows techniques like time-lapse photography. Some images simply cannot be captured properly without full manual control, especially when dealing with a drastic range of contrast or exposure.

Full manual mode allows a photographer to manage Aperture, Shutter Speed, Exposure Value, Depth of Field, Focal Point, Focus, and more. These advantages are not fully achievable with priority or Auto modes. Using priority modes is like taking the first steps toward mastery, while full manual mode is where true creative freedom begins—but it requires practice and experience.

THREE MOST BASICS A BEGINNER PHOTOGRAPHER SHOULD KNOW

Andrew Shu · 17 July 2021 · Leave a Comment

When we purchase a decent or even a high-end camera that comes with a variety of features, using the “Auto” mode all the time is fubar. Knowing the basics is not a lifetime of learning — mastering photography is. Just like music, where the basics of seven notes create countless symphonies by employing the right combinations of notes, photography also has three basic elements. Using these three basics offers virtually unlimited possibilities for creating beautiful images.

Without further ado, the three photography basics that create the right exposure in an image are Aperture (F-stop), Shutter Speed, and Film Speed (ISO – International Organization for Standardization). For a brief clarification on the acronym “ISO,” it stands for the International Organization for Standardization, which established the standard to determine film speed in photography. Meanwhile, some countries use the term ASA (American Standards Association) or DIN (Deutsches Institut für Normung)** — basically, they all refer to the same concept.

THREE BASICS

Before coming to an understanding of the correct combination of those three basics, it’s necessary to know the idea behind each one. A simple explanation of these three basics can be described as follows:

APERTURE

Aperture is the setting that determines the opening of the “window” formed by the aperture blades, allowing light to reach the film plane in film photography or the image sensor in digital photography. Some say, “photography is painting with light,” because without light, photography cannot be done. In other words, aperture controls how much light comes through.

SHUTTER SPEED

Shutter Speed is the setting that determines the duration for which light reaches the film plane or image sensor. In other words, shutter speed controls how long the light comes through.

In brief, Aperture refers to the quantity of light, and Shutter Speed refers to the duration of light.

FILM SPEED / ISO

The last of the three basics, Film Speed (ISO) determines how sensitive the film or digital sensor is to light. To understand film speed, we need to look back at film photography.

In film photography, the sensitivity of film to record an image depends on the emulsion coating on its surface. This coating allows the film to capture images. The method of coating defines the sensitivity of the film — whether it can record with less light or requires more light. In digital photography, the function of the emulsion coating is replaced by the image sensor.

Without going too deeply into the technical process of making film or a digital sensor — which is beyond the scope here — the practical purpose of these three basics is simple: they allow a photographer, through the camera, to produce a correctly exposed image.

WHAT ARE THE EFFECTS OF APERTURE?

Aperture affects brightness. A bigger aperture lets in more light, producing brighter images.

The numbering of aperture can be confusing for beginners. A bigger number (e.g., f/16) actually means a smaller opening in the lens diaphragm, letting in less light. Conversely, a smaller number (e.g., f/2.8) means a larger opening, allowing more light to pass through.

Aperture also affects depth of field, which is the span of the area in focus. A small aperture (big number) produces a larger depth of field, keeping more of the image in focus. A large aperture (small number) produces a shallower depth of field, isolating the subject from the background.

colorful-bowling-pins-toy — Image by Andrew Shu

WHAT ARE THE EFFECTS OF SHUTTER SPEED?

Shutter Speed affects motion. A faster shutter freezes motion, while a slower shutter blurs it. When photographing motion, the right shutter speed is crucial to achieve the intended result. Sometimes, a slow shutter speed is used deliberately to blur motion for artistic or aesthetic reasons — for example, capturing the continuous taillights of cars at night, or a flowing river that looks like smooth velvet.

Certain types of photography require completely sharp moving subjects. Sports photography, children, or any moving objects demand a fast shutter speed to freeze the action.

Shutter Speed also interacts with Aperture. In low-light conditions, a slower shutter speed can compensate for a smaller aperture to achieve proper exposure. Alternatively, a larger aperture can compensate for a faster shutter speed under the same lighting conditions.

WHAT ARE THE EFFECTS OF FILM SPEED / ISO?

Film Speed (ISO) affects the graininess of images. Higher ISO settings produce coarser grain. A higher ISO allows photography in lower-light conditions but compromises image quality. ISO becomes the solution when Aperture and Shutter Speed alone cannot achieve proper exposure. In the “Knowing The Functions In Your Camera” article, some other limited options are shared that can be employed before ISO needs to take charge.

LIGHT METER IN CAMERA

Every SLR (single-lens reflex) camera — whether film, DSLR, or mirrorless — has a light meter to measure exposure. Its position in the viewfinder may vary (bottom, side, etc.), but the principle is the same. The light meter indicates the state of exposure: when the pointer is at zero, exposure is correct for the current Aperture, Shutter Speed, and ISO settings. If the pointer moves toward the minus, the image will be underexposed; toward the plus, it will be overexposed. To correct this, one of the three settings must be adjusted, keeping in mind that changing one affects the others.

Refer back to the effects of Aperture, Shutter Speed, and ISO. Assuming the camera is in full manual mode: when the priority is set to Aperture, the Shutter Speed adjusts automatically to maintain correct exposure. When the priority is set to Shutter Speed, the Aperture adjusts automatically to follow the Shutter Speed changes.

So, before exploring more advanced techniques for combining the three basics, let’s get an SLR camera — film or digital — in hand.

BEFORE TAKING PICTURES

SETTING THE ISO

Firstly, set the ISO, keeping in mind the location where the shot will be taken. If there is enough light, or if the shots will be taken outdoors, set the ISO to 100.

NOTE: In digital SLR cameras, the range of settings for Aperture, Shutter Speed, and ISO is considerably wider than in film cameras. Aperture can be adjusted in 1/2, 1/3, or even 1/4 stops, and the same applies to Shutter Speed. ISO can range from 100 to over 100,000 in digital photography.

NOTE: Some creative techniques from film photography, such as push, pull, and cross-processing, are no longer commonly known among newer digital photographers. Some artistic aspects are missing in digital photography but are replaced with other advantages.

WHITE BALANCE

Film cameras do not have white balance adjustment because it is determined by the type of film used. Digital cameras, however, use image sensors, so a white balance feature is necessary. While white balance can always be corrected during post-processing in digital photography, it is recommended to set it before starting to shoot. If adjusting white balance feels complicated, just set it to AWB (Auto White Balance).

SHUTTER SPEED OR APERTURE PRIORITY?

Presumably, we are not shooting in full manual mode, where neither Aperture nor Shutter Speed has priority. Full manual mode allows the most creative control, but only for those with advanced knowledge and experience with the three basics.

Before choosing which to prioritize, consider the type of shots you plan to take. When depth of field is the most important factor — whether shallow or deep — Aperture should be the priority. Shutter Speed becomes the priority when capturing motion is more important, whether to freeze moving subjects or create motion blur.

NOTE: Most DSLRs, such as Sony and Nikon, use “A” on the dial for Aperture Priority and “S” for Shutter Speed Priority. Canon, however, uses “Av” for Aperture Priority and “Tv” for Shutter Speed Priority.

TAKING PICTURES

Indoor photography usually has more consistent lighting, while outdoor conditions change constantly. Clouds, shadows, reflections on subjects, and other factors make a photographer adjust the camera settings frequently. White Balance is usually a minor issue when using AWB (Auto White Balance), and ISO rarely needs to be changed under normal conditions. Whether using Aperture Priority or Shutter Speed Priority, adjustments often need to be made between shots.

Happy shooting!