Here's part 1 of the photography basics - simplified.
To know before taking a photograph:
Aperture : a bladed mechanism that closes and opens to define the amount of light going through the lens. Represented by the "f" number. Shown as f/2, f/5.6 etc... F/2 allows half the light available to go through, f/8 allows 1/8th or 12.5% of the light to go through and so on. As aperture changes, so does the essence of a photograph. The higher the aperture number, the clearer objects are in front of and behind where you're focusing. If its a low aperture number, only the object in focus is clear and the rest is blurred. This is known as depth of field or DOF.
Shutter speed : represented by 1/1000, 1/500, 1/250, 1/200 etc... When shutter speed shows 1000, it means 1 thousandth of a second the shutter is open. When it shows 3", it means the shutter is open for 3 seconds. If the lens of the camera is 50mm, the shutter speed of the camera should be atleast 1/50. If it is 100mm, it should be atleast 1/100. This is to avoid blurry pictures due to camera shake when handheld. If shutter speeds slower than this are needed, use a tripod. If you can, always use a sturdy ballhead tripod. Croma has one for about 1500.
ISO number : it ranges from 50, 100,200,400,800, 1600, 3200, 6400, 12800, 25600, 51200, 102400 etc... ... It shows the sensitivity of the sensor in your camera to light. The higher the number the more sensitive the sensor/film.
These are 2 important factors to consider when taking a photograph :
1. Framing : a well focused well lit photograph is of no use if its not framed properly. Consider sonali bendre photographed with a garbage truck in the background ... It is very important not to distract the viewer from the primary purpose of the photograph. Always try different angles before attempting to take a photograph. Anybody can point and shoot. It is in the chase of the perfect photograph that you, the contemporary photographer, have to move around trying to get the perfect angle.
2. Aperture, shutter speed and ISO number : If "f" is total light available, f/2 is half of it passing through the lens. Therefore, the higher the number, the lesser light passes through. Think of the perfect photograph as a glass full of water. Where the glass is the camera and the water is light. In essence, the camera takes light available , water, and captures it in a container - photographs. If the glass is not full, the photo ends up dark/ underexposed due to lack of light. Too much and it washes away all details giving over exposed pictures.
If the aperture is a smaller number, f/1.8 for example, it means that more light comes through the lens. That means the glass fills up faster. If the aperture is a bigger number like f/11 for instance, it means that lesser light is coming through the lens and the glass fills up slowly. This can be thought as regulating the rate of water flowing into the glass.
This is where shutter speed comes in. If the shutter speed is fast, it means the glass has lesser time to fill up and if the shutter speed is slow, the glass has more time to fill up. This can be thought of as the time given to the glass to fill up. By balancing shutter speed with aperture, a perfect combination is reached to fill up the glass exactly to the brim in just the right time.
A higher shutter speed is used when action needs to be stopped, like in a sports situation. Lower shutter speeds are used to indicate motion like when showing the stars moving on long exposures in the night.
A higher aperture is used when the whole frame needs to be clear and defined like in landscape photography. This means that lesser light is coming in. Higher apertures are generally teamed with slower shutter speeds. Therefore, landscape photography always requires tripods. Landscape photographs are considered good only when taken between 5:30 - 6:30 am and 6:30 - 7:30 pm or dawn and dusk - meaning lesser light, hence the tripod.
Lower aperture numbers are used in low light situations to allow more light in. They are also used for portraits and close ups to beautifully blur the background while having a sharp focus on the subject. In lower aperture numbers, sometimes, when light is filtered through an object such as the leaves of a tree in the blurred background, an effect called bokeh is observed which produces extremely pleasing circles of light which both enhances the beauty of the subject and artistic license of the photographer.
When tripods are not available, the best way to capture a photograph in low light from a handheld camera is by boosting the ISO number. By doing this the camera captures light quicker however image quality degrades rapidly past a certain point depending on the camera. Most digital cameras take photos well enough at 800-1600 ISO which should be enough for most low light situations. In daylight, it is recommended to use a ISO 100 - 400.
By balancing all three depending on requirement, the perfect photograph is produced. In a digital camera, all of this is processed and set automatically to allow you to point and shoot. However the eye is the best judge and a camera just cannot see what an eye can. So experiment and use the Manual (M), Aperture Priority (A) and Shutter Priority (S) modes more often.
Hope this helps, more later.
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