In photography, the lens is my eye while my eyes become the brain of the camera—the control center where the decisions about compositions and other adjustments are made. To me, the quality of the lens is more important than the amount of the pixels on my camera’s sensor. Without a decent lens, the powerful sensor in my camera won’t be able to bend the incident light rays to create an image. The quality of the lens is important enough for Canon to marry Nippon Kōgaku K.K.—the original Nikon—in 1934.
Tag Archives: aperture
From time to time, I host a café meet up and talk about photography. Today, a group member asks a very basic question that others seem too shy to bring up. He wants to know the definition of photography. ”It’s an art to capture a subject by using camera and lens as a medium,” one replies. “It’s a way to document time and space,” says another. Everybody has a different definition and they’re all correct. However, it seems that everyone in my group forget the most important ingredient in photography—light. According to Merriam-Webster, photography is defined as “the art or process of producing images by the action of radiant energy and especially light on a sensitive surface (as film or a CCD chip).”
What do you find when you look at your camera, any camera, film or digital? You find settings that regarded to light, correct?. ISO setting is used to determine the sensitivity of photographic films or digital imaging sensors to light. Shutter speed is used to control the duration of light allows to reach the negative or image sensor. While the aperture is used to manipulate the amount of light reaching the negative or image sensor. Since these settings work in conjunction with each other, they’re equally important when it comes to producing a well-exposed photograph.
Many beginners often overlook the ISO setting, thinking the Auto ISO will give them the peace of mind. I think differently. I think that the ISO is the most important setting and it is always the first I check each time I pick up a camera. When I see a sharp edge shadow—I’m a hardcore old schooler. I don’t look at the light but I look at the shadow to see my light—I would set my ISO to the lowest setting. With a soft edge shadow, my ISO would be set in the range of 250 to 400. ISO 500 to 640 would be set for shooting in shading areas while 800 to 6400 would be used for evening, restaurant and night club scenes. To control the duration of light, my reference for shutter speed settings is based on two factors—the focal length of the lens on my camera and the light sensitivity that I set by way of the ISO setting. Say, I’m using a 35mm lens and my ISO is set at 640, then I know my safe the slowest shutter speed is 1/30 and the highest is 1/640. Aperture settings are often based on the dof which I want to achieve but I rarely set the aperture at its widest f/ stop—unless I really have to. Often, f/5.6 is my choice for street shooting and f/2.8 for portrait.
Keep in mind, my friends. Photography is the artistry with light.
There is nothing new about this hyperfocal distance technique. Sir William de Wivelesley Abney¹ mentioned about the hyperfocal distance formula in his book in 1881. This focusing concept continued to develop until 1951, when Rudolf Kingslake² used the simplest formula to specify the concept. Hyperfocal distance is mostly known as a distance beyond which all objects can be brought into an “acceptable” focus³.
Hyperfocal distance is often use with normal and wide angle lenses since their focal distances are relatively shorter than telephoto lenses. For landscape photographers, this concept is the most useful technique to get everything in focus. For photojournalists and street photographers, this is the key to attain candid shots and quick focus. With the DSLR age, the depth of field scales have disappeared from the autofocus lenses and most of us seem to have forgotten or have never learned to use this hyperfocal distance technique. Some argue that it is unnecessary since autofocus lenses can perform faster and more precise focus. Some give up because they get confused with formulae, numbers and technical terms like Circle of Confusion⁴.
The concept can be confusing if we get too technical; otherwise, the formula is simple and easy to understand. Before we jump into the formulae, I’d like to clarify that hyperfocal distance and depth of field are not the same thing.
While Depth of field can be defined as the range of object distances within which objects are imaged with acceptable sharpness, hyperfocal distance is the focusing distance such that the far distance of acceptable focus is at infinity. Hyperfocal distance can also be the closest distance at which a lens can be focused while keeping objects at infinity acceptably sharp. When the lens is focused at this distance, all objects at distances from half of the hyperfocal distance out to infinity will be acceptably sharp.
Since hyperfocal distance has two definitions, there are more than one formula will be discussed in the next paragraphs. For the first definition, the formula is,
- H = hyperfocal distance
- f = focal length
- N = f/ stop
- c = circle of confusion limit
Below is the formula for the second definition,
For example, we are going to find the hyperfocal distance for a 35mm lens with its aperture set at f/8. Camera is a full frame DSLR.
For full frame DSLR, the Circle of Confusion value usually falls between .0291mm and .033mm. The value of .030mm⁵ is often used for 35mm film format and DSLR.
To convert millimeter to feet,
So what’s the meaning of this 16.9ft? This value tells us that at f/8, the depth of field from this point of focus is extended from some near distance to infinity.
That’s all about hyperfocal distance, folks. On my next post, I will blog about the depth of field scale and why it is related to the hyperfocal distance concept.
¹Sir William de Wivelesley Abney – (24 July 1843 – 3 December 1920) Born in Derby, England. Abney was an English astronomer,chemist, and photographer. Several technical aspects of photography were pioneered by Sir William de Wivelesley Abney. Dry photographic emulsion was developed by Abney in 1874, which later replaced the wet emulsions.
²Rudolf Kingslake - (1903–2003) Born in London, England. Kingslake earned a Masters degree in Optical Design at the Imperial College of Science and Technology. In 1937, Kingslake became the head of Optical Design department of Eastman Kodak.
³Hyperfocal distance – Wikipedia.
⁴Circle of Confusion – Also known as disk of confusion, circle of indistinctness, blur circle, or blur spot. The circle of confusion is used to determine the depth of field, often defined as the largest blur spot that will still be perceived by the human eye as a point. Wikipedia.