As modern cameras are all the better in automatically determining the parameters needed to get quality photos, manual controls are still what you need to use if you want to get the photo you want instead of the one you want the camera.
The situation is simpler if you have a compact camera that does not allow manual control – only you can leave it in automatic mode and concentrate on things like finding a good motive, composing learning, and so on. However, if you’ve been busy purchasing a D-SLR camera and holding it on an automatic, you can say that you have thrown money into the trash. How to record in manual mode are books written, but for starters you need to understand how only three parameters – shutter speed, blur and ISO speed are working.
Although it is not technically correct and actually indicates something else, the shutter speed is usually used as the exposure time, so we will use it as well. Thus, the shutter speed or exposure determines how long the light will fall on the camera sensor. The longer it is, the more photons fall on the sensor and you get a brighter picture. The situation is very simple – if you have a camera that does not move (say it’s on a stand) and shoot immobile objects, then you can freely let the camera set the exposure because every one you decide to give is a properly exposed photo. However, you will not usually take pictures of the tripod, but of the hand, and since no one has a perfectly stable hand, what exposures do you have to use?
The rule of the era of analogue appliances that is more or less valid today says that if you want a sharp photo when shooting from your hand, the slowest exposure must be the reverse of the focal length of the lens. And what does that mean? Well, let’s say that on your DSLR you have the lens you’re likely to get with it, a standard 18-55mm kit. If you shoot at its widest end (18mm), then the slowest exposure should not be slower than 1/18 seconds. If you shoot at the longest, this number speeds up to 1/55 seconds.
If you put a 70-200mm telephoto lens on the camera and shoot it at 200mm, then the slowest exposure can not be longer than 1/200 seconds. Things are even more complicated if you take photographs of fast moving objects – in short, if you are at a sporting event, do not go slower than 1/500 seconds. Against the problem you have if you intentionally want to get a blurred motion, eg for blurred waterfalls or a perfectly flat surface of the sea, you need exposure for a few seconds, and to capture traces of stars in the sky, it also works with exposures that last all night.
When we say “blend” we mean the width of the aperture in the lens through which the light passes, and we denote the f-number. The F-number indicates the relationship between the focal length of the lens and the diameter of the aperture through which light enters, but a more detailed explanation of this will be neglected this time, all you need to know is that a smaller f-number means more light coming on the sensor and that is why the lenses with a smaller f-number are faster. But except the amount of blur light controls another important thing: deep-eyed. Want to know how to make a portrait with a blurred background? No, in practice it does not work with Photoshop, but with a lens that is as long as you can and has as much aperture as possible (or as fewer f-number as you want). Of course, the longer the lens usually means the higher the price and the distance from the person you are shooting, so that the ideal lens for starting portraits will be 50mm with a f-1.8 f number. If you want the opposite of the blurred background, ie the entire scene in focus such as on some landscape, you need to expanding the lens and the larger the f-number, somewhere in the range f / 16 or f / 18, and you should focus approximately one-third of the distance to the horizon.