PHOTOGRAPHY

The term 'photography' comes from ancient Greek and means 'to draw with light'. To make this possible, the photographic technique makes use of various expedients.
By using, in particular, 'reflex' type cameras, it is possible to combine three parameters, commonly called 'ISO', 'time' and 'diaphragm'.
By 'ISO' we mean the measure of 'sensitivity', which is the ability to 'impress', i.e. to produce an image on a medium with a smaller or larger amount of light and in a more or less restricted time.
As the ISO number increases, the image will be brighter, but will capture less detail.
Exposure time is the time between the opening and closing of the shutter.
Exposure time is measured in seconds or in fractions of a second. In the latter case, cameras indicate exposure times with a whole number corresponding to the denominator of the fraction of a second considered.
The 'B' (Bulb) exposure allows the shutter to remain open for as long as the shutter release button is held down.
The 'diaphragm' is a mechanism by which the aperture of a lens can be adjusted, allowing more or less light to enter.
The larger the aperture of the diaphragm, the smaller the number by which it is indicated.
Usually, the field of view observable through the viewfinder is slightly smaller than that of the sensitive medium.
Most digital cameras store images in JPEG format. Some cameras also store images in RAW format.
The RAW format is called 'digital negative', as it saves the data from the sensor without processing it.
The advantage of obtaining images in RAW format is that it is possible to 'develop' them by means of a computer, almost always a computer, with more computing power than the computer integrated in the camera itself. The result is not only the possibility of obtaining an image with fewer defects, but also the possibility of reducing the waiting time between shots due to the absence of processing.
Many lenses allow you to switch between manual (MF) and automatic (AF) focusing modes.
Lenses are characterised by brightness, focal length and angle of view.
Brightness is the maximum aperture the lens can achieve and is denoted as 1:X, where X indicates the maximum aperture value for the lens. It follows that lower values of X correspond to higher brightnesses.
The brightness of a photo is perceived by means of the exposure meter and is measured in 'STOP' or fractions of 'STOP'.
With respect to focal lengths, lenses can be divided into wide-angle, normal (standard) and telephoto lenses.
Wide-angle lenses provide a wide view, but have a tendency to distort images.
Thanks to their focal length range, zoom lenses are able to vary focal lengths and with them magnification, field angles and brightness.
However, fixed focal length lenses offer better sharpness than zoom lenses.
There are also macro lenses that allow you to enlarge the images in your photos.
Fisheye lenses, characterised by a large field of view, can be 'circular' or full-frame.
The 'safety time' refers to the minimum time by which blurring can be avoided. This safety time can be calculated as the reciprocal of the focal length at which one is shooting.
There are various photographic techniques related to image creation. These include 'panning', 'blurring', 'B-pose' and 'depth of field'.
As rules of composition, one can mention the 'rule of thirds' and the search for diagonal lines, frames and particular backgrounds (textures). In addition, photos taken from close up, 'underexposed' and 'overexposed' photos, as well as the search for lines with typical 'golden sections' or indicating a direction of gaze, are also very effective.
Finally, in general, it may be very useful to study the scene one would like to photograph before taking the photo.