Exposure! Yes, you rightly heard. It’s a very pivotal part of photography. No matter how perfectly a photo is snapped but if it contains exposure issues, the photograph will lack appeal. It may contain all the necessary elements, right from subject, ambience, props, fitting background, framing, and other essential components. Yet, the photo will look shoddy due to the exposure flaws. It is very common for a photograph to come out as underexposed or overexposed one after it is captured.
Many photographers, nowadays, use and count on the automatic mode of the camera thinking that the camera would handle all the settings and result in a great photo. But the automatic mode doesn’t operate well perfectly and produce substandard photos. If you are a photographer and looking to snap photography masterpiece, you have to reflect on the 3 elements of exposure and comprehend their functionalities: ISO, shutter speed, and aperture. If you can grasp the interplay of these elements, you can certainly expect and produce photography gems.
Reliance on the auto-mode of a camera is alluring for photographers and it is perceivable. If you are a regular smartphone camera user, it will be a stiff task for you to deftly use a high-end digital camera. This is because a high-end camera boasts multiple functionalities and requires you to possess adequate knowledge on it especially on the exposure settings. Once you know the fundamentals of exposure, you are on your way to master the advanced modes of a camera no matter whether you have read the instruction manual or not.
ISO: ISO predominantly refers to the International Standards Organization. But when it comes to photography, it implies sensitivity to light. The function of ISO is to regulate how the sensor reacts to the light receiving from the shutter and aperture. The higher the ISO, the more sensitive it is to the light. Likewise, the lower the ISO, the less sensitive it is to light. Under normal circumstances, you should be looking to set lower ISO as it will let you attain correct exposure. On top of that, sensors perform better at low ISO settings recording good color depth and dynamic range. If you set higher ISO, chances are that you will have noise in the photo.
When it comes to shooting in daylight or well-lit scene, ISO should be set low, typically from 100-400. Counting on the shutter speed and aperture in these cases can give you correct exposure. On the other hand, if you are in a dark location, you have to scale up the ISO. If you intend to have a fast shutter speed and small aperture (deep depth of field), you may have to increase the ISO. Only by using flash, you can use low ISO even in the dim condition. But on-camera flash frequently produces substandard outcomes.
Aperture: Aperture is another factor that plays a key role in the proper exposure of a photograph. Aperture is basically an opening in the lens that restricts the passing of light through the lens. Depending on the size of the hole, the amount of light passes through the lens. You have the option to scale up and down the size of the hole by altering the aperture value on the camera. The value of the aperture is known as f-stop and it appears like f/2, f/4, f/5.6, etc. The larger is the f-stop value, the lesser the light can enter the lens. If you wish more light to enter the lens, you have to go for a smaller aperture value.
Along with regulating the entry of light into the lens, the aperture also determines the depth of field. DOF is something that reflects the focus of the entire scene in an image. When it comes to choosing f-stop, you have to choose smaller f-stop, meaning wide aperture if you want to go for a smaller depth of field. But if your motive is a larger depth of field, you have to go for a larger f-stop which means narrow aperture. With a larger depth of field, the focus will be on the entire image from the foreground to the background. And with a smaller depth of field, the focus will be concentrated on a specific focus plane letting the foreground and the background hazy.
Shutter Speed: Like aperture and ISO, shutter speed is another pivotal factor to determine the exposure of a photograph. Shutter speed is mainly the amount of time the shutter remains open to let light enter inside the camera through a lens. How long the image sensor of a camera will remain exposed to light relies on the length of time the shutter remains open. Both shutter speed and aperture function together. Shutter speed is normally measured in fractions of a second like 1/3000, 1/50, 1/400, etc. When you set the shutter speed, you are actually notifying the camera how rapidly or slowly to open and close the shutter. If you set a shutter speed of 1/3000 second, the camera will open and close the shutter very fast and a little light will get in. But if you set a shutter speed of 1/2 second, the shutter opening and closure will be slow and more light will enter inside.
Shutter speed not only plays a key role in photography exposure but also captures the motion of moving objects. If you use a quick shutter speed, it will freeze the motion of moving objects in their track while a slow shutter speed will track and record the movement blurring the objects. But when it comes to a steady picture, a specific shutter speed is necessary to shoot it perfectly without a tripod. One key point to be noted is, blurriness is not always unwanted and sharpness is not something that is always wanted. For example, if there is a car racing going on, some may wish to freeze the motion of a speeding car to manifest a specific moment while others may intend to record the motion around the track to create blurry effects. For the first scenario, the shutter speed can be something like 1/1000 and for the second scenario, you can set a shutter speed of 1/50.
In order to achieve a perfect exposure, all these 3 elements must be set and picked appropriately. A tweak in one of them will influence the other two elements and so they must be fine-tuned. This will result in perfectly exposed photos. To have a better understanding of the functioning of these elements together, an analogy can assist. When it comes to a correct exposure of photography, you can imagine it with a bucket getting filled with water through a hose. If you fill the bucket all the way without overflowing, it means you have nailed it. Likewise, if you can get the perfect amount of light in the image sensor maintaining correct ISO settings and picking right aperture as well as shutter speed, it implies you have correctly exposed a particular photograph.
Shutter speed can be compared with the valve of the faucet which you use to turn on and off the flow of water. If you turn on the valve for too long, the bucket will overflow. Contrariwise, if you turn off the valve too early, it won’t fill up. So, you have to regulate the valve of the faucet in such a way so that the bucket just fills up perfectly. Likewise, you have to set the shutter speed in such a way so that a perfect amount of light just reaches the image sensor. Or else, the image you shoot can be glaring or too dark.
Aperture is like the size of the hose that you use to saturate the bucket. Filling the bucket with a garden hose will take longer as compared to filling it with a fire hose. Assume that the water pressure is identical for both the hoses. But because the size of the fire hose is bigger than the size of the garden hose, it will require less time to fill the bucket. A hose carrying twice as much water will saturate the bucket twice as fast. The same theory applies to the aperture in the case of light getting through to the sensor. If you ramp up the size of the aperture, more light will get through and also vice versa.
Last but not least is ISO which is like the size of the bucket. If you double the size of the bucket, it will take double the time with the same size hose to fill the bucket. But if you want to keep the required time constant, you have to double the size of the hose. Likewise, if you lower your ISO from 200 to 100, it will require twice as much light to expose an image. In that case, you have to double the size of the aperture or double the duration of the shutter speed.
In a nutshell, we can conclude that there are a number of ways to expose photos correctly. As a photographer, it’s up to you to pick the one that will bring the best fruit. In order to bring the supreme outcome, apart from having exposure knowledge, you have to be creative as well. Based on the location and environment, you have to set and pick ISO, aperture, and shutter speed innovatively and this will let you nail your photography exposure. We hope, you enjoyed our write-up. For the time being, just cheers!