So, you want to learn the bare essentials of photography the easy way? Nice, you found the right place. I won't waste your time with neverending essays full of details that lead to confusion instead of clarity. You'll only find the 3+1 factors that come into play to capture the moments you care about. Quick and easy.
The settings in the camera menus may be overwhelming. To handle the technology creatively though you only need to know the three main factors to operate your camera. Every image taken is influenced by these factors, even unknowingly in the background while in automatic mode. Due to their importance they should always be thought about when taking a photo.
The aperture is the eye of your camera and controls how much light comes in and hits the sensor—the smaller the aperture (be careful: but the higher the f-stop number) the darker the image.
Below you'll find the typical f-stops with full values. Step by step half of the light is passed to the sensor. Most of the lenses you'll find have additional third stop values inbetween.
Besides letting less or more light in the aperture has an important visual effect on the image: the smaller the aperture the more depth of field you get, meaning: a wider area of what you're shooting will be sharp. You've surely seen this the other way around with portraits when the face of the model is sharp while the background blurs out.
The softly blurred bush in the foreground leads the viewer's eye to the village in the background—made possible with a wide aperture of f/1.8. © Dennis Meene
Not every lens is capable of providing large apertures like 1.4 or even 1. Besides the ability for smoother background blur (called bokeh) the main reason to buy such lenses is that you can shoot without a tripod even when there's little light. The reason: The less light that hits the sensor the longer the shutter speed has to be to provide a bright enough image.
So, the amount of light is very important but so is the duration that the light comes through to the sensor. That's the most crucial interplay you need to keep in mind. The less available light or smaller the aperture the longer the shutter speed has to be. The easy rule: Double the shutter speed to get a twice as bright image.
But be careful: If the shutter speed is too slow it's impossible to get a sharp image while hand holding your camera. As a rule of thumb try to keep the shutter speed as fast as the reciprocal of the focal length you're using. If you're shooting with 50 mm for instance you should keep your shutter speed at 1/50 s or faster.
Extreme long exposures require the use of tripods but can make possible extraordinary images. This one was exposed for approx. 4 minutes to blur the clouds and to make the water as smooth as glass. © Dennis Meene
When there's so little light that your images would blur when shooting handheld even if you're at your widest aperture the third factor comes into play: the ISO. By changing this value you basically change the sensitivity of your cameras sensor to light.
If you double the ISO your image gets twice as bright. At first glance this sounds seductive. Just crank that ISO up when it's dark and everything's fine. But you guessed it, there's a downside: the higher the ISO the more interfering signals are recorded by the sensor which leads to noise and loss of details in the image.
When you want to shoot handheld during the night you have to make excessive use of the ISO, in this case it was at 6400. Noise (see the magnification of the wall at the top left) is inevitable. © Dennis Meene
You should always keep the ISO as low as possible and increase it just in case of need. The first priority are the settings for aperture and shutter speed.
Other than the three mentioned factors the choice of the focal length doesn't effect the brightness of the picture. Nonetheless it has to be considered from an artistic point of view.
What the beginner calls "zooming" is the change of focal length to effect the image angle and crop. There are three types of lenses considering the focal length: Wide angle (up to 30 mm), standard(approx. 50 mm) and telephoto lenses(approx. 80 mm and more).
The shorter the focal length the wider the angle of the image. With wide angle lenses you are able to capture more of the scene. Telephoto lenses on the other hand capture a narrower field of view and seem to move the fore- and background closer together—the image looks less three-dimensional.
A wide angle shot taken at a focal length of 12 mm. The lines of the bridges lead from the horizon through the whole image to the viewer. © Dennis Meene
Taken at 34 mm there are no distortions in this image. It looks relatively flat and geometric. This look is similar to the human's view. © Dennis Meene
Another important aspect to consider: The shorter the focal length the more depth of field you'll get with otherwise identical settings. Wide angle lenses are sharp from the fore- to the background even with open apertures while telephoto lenses, often used for portraits, are able to blur out the background smoothly.
You successfully learned about the basic factors that are relevant to take photos. Now it's time to let your creativity flow and experience the interplay between aperture, shutter speed, iso and focal length by yourself.
Even if the first results won't please you I'll recommend using your camera completely in manual mode. Just experiment. Is the image too dark? Could you open up the aperture a bit more? Could you leave the shutter speed open longer without image shake? You will realize after a short amount of time that you'll be chosing the settings more confident and purposefully.
If you liked this site I would be very happy if you shared it so that many other photography beginners could profit from the knowledge.
And now: Enjoy photographing!