The 3-variable Equation (of photography)

I often found it weird when people told me “You take good photos because you have good gear”, but here’s the thing, gear contributes about 20% to the overall frame and the secret to great photos is 70% in your hands irrespective of which device is used to take the photo. This is a skill that is learnt and mastered which results in great photos even if you have shitty gear.

Anyone willing to spend a few minutes to understand the“three-variable-equation” can become a better photographer in no time.

There are three main variables that govern photography and I think photography is the art of solving this three variable equation. The variables encompass the fundamentals of photography and this blog post is dedicated to unwrap the variables in the simplest way. Let’s jump into it, shall we?

Behold the ‘variables‘ in their full glory:

Aperture size
ISO
Shutter-speed

Aperture-size

How much shall pass?

Every camera sensor captures the image via the light that hits the sensor after passing through a hole. This hole is called the ‘aperture’ and varying its size varies the total amount of light that is let in. The size of the aperture is measured in “f-stops, where, bigger the f-stop, smaller the aperture size.

Now that the definition is out of the way, let’s see how it affects the photo.

Lower aperture/f-stop (or big hole size) results in photos with a shallow depth of field ( the subject is focused while the background is not)
High aperture/ f-stop (or small hole size) is able to focus light from various planes and thus results in a sharp photo with most of the things in focus.

So how does this translate into application?

The lower f-stops allow those dreamy portraits with focus on the person and a blurry, bokeh background. Higher f-stops allow you to capture the whole landscape in all its glory as everything will be in focus. However, one thing to note here is that most smartphones have fixed aperture sizes owing to the phone’s thickness (usually a low ~2 f-stop) thus constraining the photographer to get more creative and work with this constant aperture.

ISO

How sensitive art thou?

( I don’t think it has a full form as I haven’t found it yet (yes, I have searched for it a lot), if you know about it contact me...)

ISO is the factor that tells how sensitive the camera sensor is. In layman terms

A high ISO means more light is observed and recorded
A low ISO means that not all the light that hits it is recorded

So what exactly does this ISO do?

On bright days, the ISO is lowered so that less light hits the sensor whereas it's bumped up in low light conditions to record more light and get a well exposed or optimal photo (Not too dark, Not too bright) It's as simple as that. However do bear in mind that a high ISO would lead to unwanted noise in the photo as the camera tries to approximate the pixel’s value in a dark spot ( and usually getting it wrong)

Shutter-speed

How fast art thou?

Shutterspeed refers to the amount of time the shutter is open to let the light hit the sensor. Think of it as a time window during which the outside world can interact with the sensor. It is denoted by a fraction, the unit being seconds. Higher the denominator, lower is the time for interaction. In a typical camera the shutter speed can vary from very short bursts of ~1/4000th of a second to long durations of 30s.

So how do you apply this?

When anything moves the light from the new position hits our eyes and thus we perceive motion.

By applying this concept and making shutter-speed\ very fast (say 1/2000th of a second) we essentially allow only the initial light from the scene to be recorded in the camera and thus ‘freezing motion‘ and obtaining crisp, static images.
Similarly, by using slower shutterspeed fast (say 10s) we obtain the light from every position the object was present in during that duration thus allowing us to capture “ghost-trails', “motion-blur '' or “long-exposure” photos.

That's all folks. Hope you enjoyed learning about the three-variables that govern photography! Try experimenting with these in the manual mode of your phone or camera (To all those who wondered why does the percentage add up only to 90% only: that was intentional, the rest 10% is pure luck :)

Happy learning!

More content about photography coming your way soon!