Depth of field plays an important role in photography because it determines the areas of clarity and blur in a photo. Strictly speaking, objects can only appear clear at a specific distance. However, people cannot accurately judge the clarity of objects, so a range of distances is needed to ensure that objects within that range are clear. This range is known as the depth of field of an image.

(Photo by jmbernicle)

The depth of field scale (hereinafter referred to as the DOF indicator) is a rough measuring tool that calculates in centimeters or feet to help photographers predict and calculate depth of field ranges under different combinations of focal length, aperture, and shooting distance. To provide photographers with a more accurate estimate, the DOF indicator is designed with scales and indicator lines.

The depth of field scale is a prominent feature of Simera lenses (Simera 35mm and 28mm), sparking enthusiastic discussions among photographers who have shown great interest in these lenses. We can find similar designs (DOF indicator) on other vintage film lenses.

To demonstrate how the depth of field indicator adds elegance to photography, this article will explore some innovative cases with you.

★★★ How to Determine Depth of Field?

First, we need to understand the three rings on the Simera lens. (Simera 35mm and 28mm)

1. Aperture Ring

As shown in the following image, the front ring is the aperture ring, marked with aperture values such as f/1.4, f/2.8, etc.

2. Focus Ring

As shown in the following image, the rear ring is the focus ring, marked with focus distances.

3. Depth of Field Scale Ring

Between the aperture ring and the focus ring, we can see some cut-out spaces that will be illuminated (filled with red dots in the holes).

The following is the usage instruction for the DOF indicator on the Simera 35mm.

-- If the aperture is set to f/1.4 and the focus distance is 0.7 meters, then the two filled red dots will align with the 0.7 meter focus distance. This means that objects falling within this range can be focused, while objects outside this range will be blurred.

-- If the aperture is set to f/16 and the focus distance is 0.7 meters, all points will be marked in red. The vertical correspondence for these 16 points to the focus distance is 0.45-0.91 meters, meaning that if an object falls within this range, it will be clear, and if it is greater than 0.91 meters, it will be blurred.

For users of film cameras, the depth of field scale has practical uses. With the depth of field scale feature on Simera 35mm and 28mm, photographers can predict the approximate range for objects to be clearly displayed and create satisfying photos when inspiration strikes.

★★★ Creative Use of DOF Indicator -- Hyperfocal Shooting

1. What is Hyperfocal Distance?

Hyperfocal distance is usually represented by H. Its precise definition refers to the distance from the lens to the closest point that is in focus, when the lens focal length and aperture factor F are fixed, and the lens is focused at infinity.

(Source PetaPixel)

2. How to Calculate Hyperfocal Distance?

As illustrated, H is the hyperfocal distance, f is the focal length, N is the aperture value, and c is the depth of field coefficient (dependent on sensor size and format).

For example, if you are using a full-frame camera with a 35mm lens equipped with an f/11 aperture, the hyperfocal distance is approximately 3.7 meters. This means that when your camera is focused on an object at 3.7 meters, all objects from 1.85 meters to infinity will be in focus.

Depth of field has been calculated according to the formula. When you fix the aperture value and focus distance, the clear range will be presented on the Simera 35mm f/1.4 and 28mm f/1.4 lenses.)

3. Practical Applications of Depth of Field

The purpose of using depth of field is to increase the depth of field in photos. The greater the depth of field, the stronger the sense of layers and three-dimensionality in the photo. This is very useful for photographing landscapes, architecture, street scenes, and other wide-angle scenes, enhancing the attractiveness and expressiveness of your photos. But ultimately, the depth of field depends on the subject you want to photograph.

A more interesting play on depth of field is "capturing moments," commonly used in street photography. Determine the shooting distance and depth of field range, wait for the right subject to pass through the estimated shooting range, and you can take pictures without looking through the viewfinder. This is how you capture the "decisive moment" in an instant.

Below is a set of interesting cat photos taken creatively with hyperfocal distance by KOEKKOEK (Instagram account).

There must be even more innovative ways to use the depth of field scale to enhance your photography experience. Feel free to explore and share on our social media accounts. (Facebook Group or Instagram)