Pho­to: pixabay.com

Aper­ture is a dark horse for begin­ners in pho­tog­ra­phy. Many of them get con­fused in the val­ues ​​and do not under­stand what specif­i­cal­ly changes because of them (“f / 1.4 or f / 5.6 — what’s the dif­fer­ence??”). In this arti­cle, we’ll explain, with­out get­ting too tech­ni­cal, how aper­ture works, as well as a few inter­est­ing uses for it.

What is a diaphragm: in simple words about the complex

To make it eas­i­er to nav­i­gate when set­ting the para­me­ter, it is enough to know about the tech­ni­cal device of the aper­ture only that this is a hole in the lens that trans­mits light to the matrix. The diaphragm works like the human eye: when we look at some­thing in the dark, our pupils dilate, while in the light they con­strict.

The aper­ture in the lens is almost like its pupil, which can be adjust­ed man­u­al­ly based on the spe­cif­ic sit­u­a­tion. The val­ues ​​​​of this para­me­ter are capa­ble of intro­duc­ing a novice pho­tog­ra­ph­er into a stu­por, since the low­er the num­ber, the wider the hole is open.

The thinnest “petals” are respon­si­ble for chang­ing the size of the diaphragm, which are dis­placed and form a mul­ti­fac­eted hole for trans­mit­ting light to the matrix. Pho­to: adobe.com

For exam­ple, f/1.4 is much larg­er than f/8. This is a lit­tle incon­ve­nient, but there is one ele­men­tary expla­na­tion that will make the indi­ca­tor more under­stand­able. Imag­ine, for exam­ple, that f/10 is a frac­tion of some­thing whole (like 1/10). It turns out that at f / 10 the aper­ture in the lens will be small­er than at f / 2 (after all, 1/10 of the cir­cle is much small­er than 1/2).

We fig­ured out the aper­ture val­ues, so you can move on to the meth­ods of using it in prac­tice.

1. Exposure, shutter speed and aperture — how to set

Adjust­ing the aper­ture changes the expo­sure. The wider the petals of the lens are moved apart, the more the light-trans­mit­ting hole in it is open and the more the matrix will be exposed. As a result, we get a brighter frame. Try it out by tak­ing a series of shots of the same sub­ject under iden­ti­cal light­ing, chang­ing only the aper­ture (shut­ter speed and ISO sen­si­tiv­i­ty). In this case, you will see how brighter pho­tos are obtained with small­er aper­tures.

Accord­ing­ly, the wider the aper­ture is opened, the slow­er the shut­ter speed must be to achieve the cor­rect expo­sure. It is also nec­es­sary to select the ISO sen­si­tiv­i­ty (ISO val­ue), although the rule always applies for inex­pen­sive lens­es: the low­er it is, the less grain­i­ness and noise in the pic­ture. It is bet­ter not to set the ISO above 200–400 units. With pro­fes­sion­al lens­es, you can work at high­er val­ues ​​with­out notice­able dete­ri­o­ra­tion in qual­i­ty.

Thus, the expo­sure is con­trolled by the aper­ture, although this is not its main pur­pose. The main prop­er­ty of the aper­ture is to change the depth of field, or DOF.

2. DOF and camera lens aperture — how to achieve the desired blur

Depth of field (DOF) defines the areas of sharp­ness and blur­ring from the fore­ground to the back­ground. Have you seen por­traits where the back­ground is com­plete­ly blurred? All of them were shot with a shal­low depth of field (or processed in a graph­ics edi­tor, but that’s anoth­er sto­ry). When both the fore­ground and the back­ground are clear­ly vis­i­ble in the pic­ture, it means that the pho­to was tak­en with a high depth of field.

To achieve bokeh, where the main sub­ject is sharp and the back­ground is out of focus, you need to open the aper­ture as wide as the lens can. This is espe­cial­ly appro­pri­ate for por­trait pho­tog­ra­phy, when you need to “blur” the entire envi­ron­ment and focus on the main char­ac­ter.

The back­ground blur effect is suit­able not only for por­traits, but also for prod­uct pho­tog­ra­phy. Pho­to: stuckinplastic.com

But there are also reverse sit­u­a­tions when a small aper­ture is required (remem­ber, these are high val­ues). For exam­ple, it is nec­es­sary when shoot­ing archi­tec­tur­al objects or land­scapes. We will talk about this fur­ther.

3. Aperture value in the camera when shooting moving objects

By chang­ing the aper­ture, you can “freeze” or “blur” the move­ment, depend­ing on the sit­u­a­tion and the idea of ​​​​the shot. A hole in the lens opens — more light enters the matrix. As a result, the cam­era, in order to main­tain the pre­vi­ous expo­sure, short­ens the shut­ter speed. This makes it pos­si­ble to pho­to­graph fast-mov­ing objects with max­i­mum detail. This tech­nique cre­ates an inter­est­ing effect, as if mov­ing objects in the cam­era are sta­t­ic. Although it is not always appro­pri­ate, as it is not able to empha­size the dynam­ics.

There is also a reverse sit­u­a­tion when you need to “blur” the move­ment. In this case, you can use the tech­nique of shoot­ing an object with pan­ning: you focus on an object and fol­low the cam­era in the direc­tion of move­ment, and then take a pic­ture. With prop­er skill, very dynam­ic shots are obtained: the main object is sharp, and the sur­round­ing back­ground is blurred. In this case, the aper­ture must be closed in order for the shut­ter speed to increase.

4. Open aperture in the camera in low light

When shoot­ing in low light con­di­tions, the abil­i­ty to open the aper­ture wide can be very use­ful. For exam­ple, if you are pho­tograph­ing actors dur­ing a per­for­mance in a the­ater or shoot­ing indoors with insuf­fi­cient light­ing, you will need to set the aper­ture low­er.

For such sit­u­a­tions, fast lens­es are suit­able — from f / 2.8 and below. They lit­er­al­ly help the cam­era to see in the dark almost bet­ter than the human eye. With bud­get pho­tog­ra­phy equip­ment, this effect can­not be achieved. For exam­ple, the aper­ture of a Nikon or Canon cam­era in kit lens­es does not drop below f / 3.5, so it is more dif­fi­cult to shoot in dark con­di­tions with them than with high-aper­ture fix­es.

The aper­ture range for most kit lens­es is f/3.5 to f/5.6. This is always indi­cat­ed by appro­pri­ate mark­ings. Pho­to: wikimedia.org

5. How best to set the aperture and shutter speed in the camera for a family report or shooting children

If you are a begin­ner and you are faced with the task of pho­tograph­ing active chil­dren, you can give the aper­ture set­ting to auto­mat­ic. The fact is that when mov­ing objects in the frame, shut­ter speed plays a more impor­tant role. Set it so that the image of run­ning chil­dren is not blurred in the pic­ture (aver­age val­ue is from 1/125 to 1/500 s).

If you still want to con­trol the aper­ture man­u­al­ly, first achieve such a depth of field that all the actors “fit” into it. Expe­ri­ence is impor­tant here: for exam­ple, it will be dif­fi­cult for a begin­ner to shoot active chil­dren with a prime lens with an aper­ture of f / 1.4 or f / 1.8. But an inex­pen­sive whale lens is much bet­ter for this: its depth of field will be quite enough (its aper­ture ranges from f / 3.5 to f / 5.6).

6. What is the aperture value of a digital camera to choose for landscape or architectural photography

In these sit­u­a­tions, we start from the depth of field. If you need both the fore­ground and the back­ground, we select a suf­fi­cient depth of field so that it cov­ers all the key ele­ments. In this case, we cov­er the hole to f / 11 — f / 16. If set even low­er, sharp­ness may dete­ri­o­rate.

With a wide aper­ture in this land­scape, only the near part of the fence and the tree would be in focus, and the image of every­thing else would be blur­ry. Pho­to: wikimedia.org

When there is no fore­ground, and the sub­ject is far away from you, it is bet­ter not to use the widest aper­ture. Instead, adjust the expo­sure by low­er­ing the ISO. A tri­pod will also help to achieve the best result.

7. Portrait mode in the camera and aperture, or how to create a bokeh effect with it

When work­ing with a pos­ing mod­el, you can safe­ly “play” with the adjust­ments, thus choos­ing the best ones for an aes­thet­ic shot. To get a beau­ti­ful por­trait, iso­late the sub­ject from the back­ground with a min­i­mum depth of field and a blurred back­ground. To do this, on a whale lens, open the aper­ture to the lim­it f / 3.5. If you have a fast prime lens, you can even close the aper­ture a lit­tle. For exam­ple, if it allows you to set f / 1.4, even f / 1.8 may be enough for you. This way you will increase the detail and get rid of chro­mat­ic aber­ra­tions.