With the digital always shooting automatically and the machine does everything alone. Can I modify something and put something of mine? [6/8]
With the digital always shooting automatically and the machine does everything alone. Can I modify something and put something of mine?
Before answering this question you have to say a couple of things about the images that are around. The first is that there are many photos "taken well", but there are also many "made and that's it.
The second is that the good photographers take photos exactly as they want them and not "how they come", even if many think the opposite ... of the frame we will talk about it at another time. For now, however, we see how to take a photo in the manual, that is, checking some parameters to obtain the desired effects.
In order for an image to be recorded, both on traditional and digital format film, there is a need for light, and it is no coincidence that the wordphotographyIt means "writing with light". Now, making a very trivial comparison with the human eye, we could say that a camera is structured a bit like him, even if obviously in our eye more complex things happen than in a camera.
Based on the light conditions, the iris, in the shape of a diaphragm, dilates or narrows the pupil by dosing the amount of light that enters the eye; Then the image passes through a lens, which in the eye is the crystalline, and finally fixes upside down on the retina, or on our film or microchip.
The diaphragm
Just as happens in the eye, when we resume a very illuminated scene we will have to close the diaphragm more to prevent too much light from investing the emulsion or sensors thus making the photo "burned", while in order to be able to record a dark scene it will be necessary to open the flaps of the diaphragm to the maximum otherwise our image will be dark.
The diaphragm also allows us to regulate the "depth of field", that is, to blur or put more focusing everything that is found before and after the main subject. The rule is that the more the diaphragm is closed and the greater the clear and naturally vice versa area.
Therefore, if for example we want to resume a field of daisies in its entirety we will keep the diaphragm closed so as to have as many flowers correctly focused.
And if instead we want to photograph a flower by isolating it from the rest of the plants we will open the diaphragm to the maximum. For more or less marked effects we will use the intermediate values.
The lowest number of the diaphragm indicates its maximum opening and also gives the idea of how bright a goal is. Remember Barry Lyndon?
To film the candlelight scenes, Stanley Kubrick's director asked Zeiss to build special objectives so bright that you can resume images almost in the dark: the maximum opening of the optics was F: 0.7! Today it starts from 5.6 upwards ...
(photo:Reduced field depth obtained with a very open diaphragm)
Another thing to know about the diaphragm is that the old photojournalists and paparazzi had no autofocus system and could not afford the luxury of taking blown photos, especially at night and outside the night clubs.
To avoid the danger of out of focus they used, as Ansel Adams taught the "hyperfocal distance".
If you happen to have an old manual lens in your hands, observing the barrel you will see beads marked, often colorful, numbered in the same way as the openings of the diaphragm.
By positioning the "infinite" symbol, engraved on the scale of distances, on the notch corresponding to the diaphragm used at that moment, the focus will extend towards us until the distance that will be read in correspondence with the other notch of equal color.
By carefully observing the scale of hyperfocal distances engraved on the various objectives, we immediately realize that with more closed diaphrams it will always correspond to a depth of greater field, and that this amplitude will also depend on the focal length of the optics used: with the Grandangoli, in fact, it will be greater and with the telephoto lenses. (Photo: A scene from the film Barry Lyndon by Stanley Kubrick shot in candlelight).
Next time we will say something else on the diaphragms and talk about the shooting times ...)
Complete photography course
- Photography course: which camera to choose?
- Photography course. The beginning: useful tips
- Photography course: sensitivity
- Photography course: blurry or blurry?
- Photography course: the circle of confusion
- Photography course: apertures
- Photography course: the drums
- Photography course: how to hold the camera
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