To create an image, a digital SLR camera (or DSLR) will need the following 3 elements:
- ISO (ASA)
- Aperture (Diaphragm)
- Speed (Speed)
This combination of the three elements will make an image. With the right combination, we will be able to create a perfect photo. And conversely, if it is not right in combining these 3 things, then we will not reach the correct exposure or lighting. Let us consider more about these three things deeper, in order to find out more about how a digital camera works:
ISO
ISO is the sensitivity of the camera sensor to light. This sensor is useful for recording light, and makes it an image. The light around us has different intensities, so to capture an image in very bright light requires a different ISO if we take pictures in a dark room.
During the cliché, each film roll has an ISO specified. So for example we will do a photoshoot outdoors during the day, so usually we will install a film roll with ISO 100. If we plan to pass photos in the room, usually we will be advised to buy ISO 400 film roll.
But in today's digital world, photography is greatly facilitated by digital cameras. A photographer is now able to change the ISO or sensitivity of the sensor just by pressing a button. We no longer have to replace the film roll if we move locations from outdoor to indoor, and vice versa.
Digital cameras now have an ISO range ranging from 50-25,600, even the latest technology allows a higher ISO, so it is helpful to capture images in very minimal light conditions. But naturally, what is used is ISO 100 to 1600.
The higher the ISO is used, then:
=> The higher the 'noise' in the image. This 'Noise' is a spot that is obtained in an image, which often appears when taking a photo in a dark room using a cellphone.
=> The image will become brighter - because the sensor becomes more sensitive to light.
=> Image quality is decreasing. Due to disturbing noise, taking pictures with a high ISO will reduce the detail of an image.
So, as a standard rule, use the lowest possible ISO that can be achieved. If you do a photo session outdoors in the hot sun, use ISO 100-200. For shooting in a room with sufficient lighting, use ISO 400 - 800. And when you pass the photoshoot at night or in a dark room, use ISO 1600 - 3200. Don't be afraid to use a high ISO, because digital cameras are now very sophisticated and able to anticipate excessive noise.
APERTURE (DIAFRAGMA)
Aperture or diaphragm is the "opening" of the lens that we use. These openings are measured by the term "f stop", for example "f1.2, f2.0, f8.0, f11, and so on. The smaller the f-stop number, then:
=> openings will be bigger
=> more light is allowed to enter the sensor
=> the image will be brighter
=> "Depth of field" or the focus space will narrow.
Each lens has a different f-stop. For example, the 50mm f1.8 lens means that the 50mm lens has an f1.8 diaphragm in the largest opening. Zoom lenses such as the 18-55mm f3.5-5.6 mean that they have the largest openings at f3.5 when using them at 18mm, and have the biggest openings f5.6 when zooming at 55mm.
Large openings will allow more light to enter the camera to be recorded by the sensor. Not only that, the focus space will also be affected. "Depth of field" which is good for shooting models is a narrow one, so that the model is in focus and the background is blurry. So that is, use a large opening when the photo model or where you want to separate an object from its background. For landscape or landscape shooting, the photographer usually wants to capture the entire composition sharply, then use a small f-stop, which is f8.0 or f20
SPEED (SPEED)
The speed in question is how fast the camera shutter is to expose the light into the sensor on the camera. This speed is measured in seconds, for example 30 ″ on the camera means 30 seconds. For faster speeds, the camera will usually be written 125, which actually means 1/125 seconds (0.008 seconds). The ability of digital cameras now usually reaches 1/8000 seconds, which is often used to take pictures of an action such as a sports game.
The slower the speed, then:
=> the more light recorded by the sensor
=> the image will become brighter.
Human hands are usually able to hold the camera without a shake at speeds of 1/60 - 1/200, so if you take pictures by holding the camera (without using a tripod), try to make the speed at 1/60 - 1/200. If you want to be able to record actions or movements that are fast enough, like someone kicking a ball, use a speed above 1/200.
Conclusion
So are the 3 elements used by a camera to create images. With a combination of ISO, speed and aperture, we can produce perfect photos. Don't be afraid to experiment with combining these three things, because each has an impact that can make your photography even more impressive.
Tip: Always try to use the lowest ISO that can be achieved, so that the quality of the photos obtained is maximum with minimal noise.