How to choose the settings of the camera to get good portraits (either with natural light or with flash)
Achieving a good portrait is not a simple task, especially for beginners. These must not only have a certain mastery of the equipment and the necessary technique , but they must also face the challenge of managing the portrayed model . To make the first part a bit easier, here are some tips for newbies on how to adjust the camera to achieve a portrait with good results.
Because we have certainly talked many times about how to improve our portrait photography , but perhaps we lacked an article where we explained the most basic : What are the best values of diaphragm, speed and ISO, how should we focus, what kind of objective is better, etc. That is, a series of practical tips for novices on what are the most appropriate settings for portraits, whether we want to make use of natural light or if we are going to resort to flash .
Portraits with natural light
We started with what is undoubtedly the most common option ( and also recommended ), use natural light, seeing how to configure the camera to achieve good portraits with this type of lighting. Of course, first of all we have to say that we talk about doing it in manual mode , which will allow us to have a complete and creative control of the exhibition.
Focal length and focus
Of what are the best targets for portrait Yes we have spoken, and it is common currency is best to use a short telephoto lens, on the order of 90 to 135 mm (35 mm equivalent). In addition, it is convenient that it is a luminous objective , since it allows better defocuses. And if it is fixed it will be ideal, since its image quality is usually greater than the zoom .
Even so, we can also use the variable focus lens that usually comes in the camera kit (adjusted to those focal lengths), since well used can be very profitable .
Be that as it may, it is recommended that we adjust it in manual focus mode so that the focus point is well fixed in the eyes of the portrayed , which (unless we look for some special effect) will always be recommended.
As for the values of the exposure triangle (you know, diaphragm , shutter speed and sensitivity ), it is best to start by adjusting the ISO to the minimum value that the camera allows to achieve the best image quality and avoid possible noise, which can also be very pernicious in this type of photos. However, depending on the light in the scene we can compensate the exposure by raising the sensitivity if we see it necessary (eye, always within values that we know will not give problems ).
The following is then the diaphragm , which we adjust depending on the depth of field we want to have in the photo. A very common example is that we want to blur the background (as in the photo above), for which we must use a diaphragm as open as possible, ideal values between ƒ1.4 and 2.8 . If, on the other hand, we want everything that appears behind to be focused (as long as it does not distract from the protagonist of the photo) we will have to do just the opposite: close the diaphragm.
In between we have the option (highly recommended) to choose the sweet spot of the objective that will be the setting where the optics offer its best performance . This point is usually two or three light steps above the maximum opening; so for example, a goal ƒ2.8 will have its sharpest point around ƒ5.6 and ƒ8.
Finally, it will be time to decide the shutter speed , which we will choose according to the other two values following what the photometer tells us, whether it is the camera (the most usual) or an external one . Of course, you have to pay attention to the value to avoid possible trepidation , so it should be at least 1/125 sec (and going up) to achieve the desired clarity , unless we are using a tripod .
Certainly for this type of photos it is advisable to use the center-weighted measurement mode , which gives more importance to what is located in the middle of the image where, logically, the face of the person portrayed is usually located. Only in very specific cases (like the one below) would it be advisable to use the point mode, to measure the light in the eyes, and in principle the matrix is not recommended.
Portraits using flash light
We now talk about making photos using artificial lighting , a somewhat more complex practice that requires different adjustments to the previous case. Of the flashes we have also talked long and hard because they are a very useful element but that, certainly, has its complication and its peculiarities .
It is true that if we want to get a professional portrait we have to know that there are many types of flashes and lighting equipment , and use configurations with several studio flash , but as this article is aimed at beginners we are going to limit ourselves to talking about how it would be to use a simple external flash (the kind of pop-up that many cameras include, we discard because of its low power).
Settings for portraits with flash
There is nothing to comment on the focal length and the focus mode, since in this case nothing changes with regard to taking photos with natural light. As for the exposure settings, we talked again about exposing in manual and also using the flash in this way . It is true that if we have a flash with TTL , which varies the power of light according to the scene, it will be easier, but what we want is to learn to use it in manual mode so that the use of other configurations will be even more simple.
When exposing shooting with artificial light, our settings will depend on the guide number of the flash in question. A figure that serves as a guide (hence the name) to know the extent of its light and which determines the diaphragm that we should use based on the relationship Diaphragm = Guide Number / Distance . Since we are working in a controlled environment, we can measure the distance to which the subject will be photographed and divide that number by the guide number to obtain the diaphragm value that must be placed in the camera for a correct exposure.
Now, you may be wondering what happens with ISO and speed . Well, these are values that, in principle, will be fixed . The sensitivity for two reasons, the first because again (and this time with more reason) we are interested in the lowest value that the camera allows to obtain the highest quality and the least possible noise. The second, and more important, because that guide number we are talking about is calculated based on a standard sensitivity value, normally ISO 100 , and will only vary if our camera’s standard is ISO 64 or 200.
As for the shooting speed, as you know in principle you have to leave it fixed taking into account the synchronization speed that allows the camera and flash binomial. A value that usually (in non-professional models) is usually 1/250 sec (and below), to ensure that the flash is captured in our shot.
“Fine” settings for portraits
Now, this we have told is the theory to expose correctly with flash, but since what we are talking about is to get good portraits, we must point out some specific considerations . The first related to that, as you already know, the flash light is very intense and powerful which can have strong reflections on the faces as well as deep shadows on the face and backgrounds.
Since our intention is to use the flash without looking like it , there are several possible strategies to follow. The first use some type of diffuser to qualify the light that comes out of the torch, so that the one that reaches the portrayed is softer and more nuanced. Another is to lower the power of the flash (if possible) to use it more as a filler than as a main light in the case that we are in an environment where there is some natural lighting.
In both cases, as you can understand, we will have to adjust the exposure according to the amount of light that is lost when using these two resources; and although you can not say a fixed value (especially if we use homemade diffusers ), in principle to open the diaphragm one or two steps of light should be sufficient.
On the other hand, if we want to be able to use an open diaphragm to make the background unfocused, we can resort to the latter (lower the power of the flash) and also to another interesting resource: Use a neutral density filter . For example, if we use one that subtracts three light steps, this should allow us to shoot at ƒ2.8 instead of ƒ8.0 without touching the rest of the exposure values.
In any case, the great advantage of the immediacy of digital photography will allow us to adjust the values in situ and verify that the results are adequate . And we hope that with these tips you have clear how to choose the settings of the camera to get your portraits level up.