What is Photography

Photography Basics

When light falls on an object and reflected to our eyes, we can see the object. When this light is, by proper mechanism, directed towards the sensor of a camera or a film, an image of the object can be recorded.

f/3.5, 1/400 sec., iso-250, FL-26mm, Nikon d810, Tamron 24-70mm f/2.8, Location: Pushkar, Rajasthan, India 2016.

Table of contents:

• ● What is photography
• ● Image formation inside a camera
• ● Under-exposed and over-expose image

Photography is an art, it is science too. The science of photography is related to OPTICS, a branch in physics which deals with light. We begin to learn the technical aspects of photography, and in time, may master some techniques of photography, at least to some extent.

f/13, 1⁄250 sec., iso-400, FL- 24mm eqv., Nikon d810, Tamron 24-70 f/2.8, Location: Jaisalmer, Rajasthan, India 2015.

But the Art of photography is different thing. It is related to how a photographer visualises his surroundings. An ordinary person does not see this world as a poet sees; in this way a true photographer also differs in his/her visualisations. It is the process of developing our eyes, and all the senses towards the happenings of this world.

Then and now

The earliest saved photographic image (Heliograph on pewter plate) from 1826 or 1827 by Joseph Nicéphore Niépce, taken at Le Gras, France.  Source: Wikipedia

Joseph Nicéphore Niépce (French:7 March 1765 – 5 July 1833), was a French inventor and one of the earliest pioneers of photography. Niépce developed heliography, a technique he used to create the world's oldest surviving product of a photographic process: a print made from a photoengraved printing plate in 1825. In 1826 or 1827, he used a primitive camera to produce the oldest surviving photograph of a real-world scene.  Source: Wikipedia

Science of photography has travelled through a long way since then. Today, the James Webb Space Telescope developed by NASA can see objects over 13.6 billion light-years away by using infra-red technique.

The first anniversary image from NASA's James Webb Space Telescope displays star birth like it's never been seen before, full of detailed, impressionistic texture.  Source: https://webbtelescope.org

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It is said that "A picture is worth a thousand words". When a photograph is displayed along with a description, no doubt that the photograph will attract us first, even before we read the description.

f/8, 1⁄200 sec., iso-100, FL-152mm eqv., Nikon d7000, Nikon 18-105, Location: Simla, HP, India 2013.

Image formation inside a Camera

A true story-telling photograph is really worth a thousand words. A description may be indecipherable, due to unknown words or language; but a photograph may communicate feelings instantly, without any hardles of language etc. Does the image above tell you some story?

A camera works in the same way as our eyes work. Light rays reflected from an object travel through the lens of a camera, then bend towards the focal point due to refractive properties of the lens. The refracted rays then reach the sensor or film to form an image of the object flipped vertically.

There are innumerable points like A & B which are spreading light to the sensor in the same way as points A and B.

Light is the fundamental requirement to make a photograph. If an object does not reflect light, it cannot be photographed. The basic properties of an image, like brightness, contrast, colour-saturation, colour-temparature(or white balance), tone and mood, all rely on the quality of light present in the scenario.

Light travels through a straight line. When it hits an object, it is reflected back. Light can also pass through transparent objects, like a piece of glass. When light-rays pass through the lens of a camera, they bend and meet at a point on the sensor or film. This change of path of light happens due to the refractive property of the lens. If the rays hit the sensor at correct point by proper focusing technique, we get a sharp image in the form of a digital file.

Under and over exposure

In the following image, proper light has been captured, so we call this a "properly exposed image".

f/8, 1/200 sec., iso-125, FL-32mm, Nikon d810, Nikkor 16-35 f/4, Location: Near Leh, Ladakh 2018.

But, in the following two images, the first one is having less light than required; the second image has more or excessive light than required. So we may call them "under-exposed image" and "over-exposed image" respectively.

In general, the word exposure in photography means the overall brightness of an image, and henceforth, the term will be used frequently.

Except in some special cases, we usually want our images to be properly exposed; not under-exposed or over-exposed. The key to shoot a properly exposed image lies in setting a correct aperture, shutter-speed and ISO through the buttons/menus of the camera before we finally press the shutter. The above three terms together may be defined as exposure triangle of photography.

f/22, 15 sec., iso-64, FL-24mm, Nikon d810, Tamron 24-70mm f/2.8, Pushkar, Rajasthan, India.

An under-exposed or over-exposed image can be corrected [only to some extent] through post-processing with photography softwares, but it is always better to use correct exposure settings in the field itself. Also, if you shoot in raw format, the processing part will result in a better image than shooting in jpg format.

f/11, 1/50 sec., iso-100, FL-10mm(15mm eqv.) , Nikon d7000, Sigma 10-20, Location: Badarpurghat, Assam 2015.

In the next page we shall discuss exposure triangle which mainly consists of three important settings contributing to the overall exposure of a photograph, namely, aperture, shutter-speed and ISO; though the first two (aperture and shutter-speed) are directly related to gathering of light on the sensor.

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