Enhancing pose, marked background blur, chosen decor, portrait photography is an art in its own right and is one of the most popular practices of photographers. But before taking the shot that will transform your friend into a real photo model, there are a few prerequisites, including choosing a suitable photo lens. Let’s see together the essential criteria so as not to make a mistake when buying!
Let it be said, there is no “special” portrait focal length. Of course, the focal lengths are given only as an indication and do not represent an absolute rule . Each photographer is free to do what enchants him to sublimate his subject or convey his message. However, there are some recommendations to get a good result when starting out in photography.
We will then avoid lenses with a short focal length, sensitive to image distortion, at the risk of having an unflattering rendering of the subject or that the latter does not occupy an important place in the composition of the image.
We will then opt for an objective whose focal length is preferably greater than 50 mm . We often talk about an 85mm lens for portraits up to 135mm through 100mm for those wishing a tight framing and a background little present.
You will have to pay attention, of course, to the conversion factor linked to the size of your sensor. If you have a Canon APS-C camera for example, you will need to multiply the focal length by x1.6 or x1.5 for a Nikon APS-C , to get an idea of its equivalent full- frame angle of view. If you want a similar rendering to 85mm, then a 50mm will do just fine.
The opening of the lens
Many newbies wonder how to achieve the famous background blur, bokeh , which focuses attention on the sharp subject and blurs the background, especially when it doesn’t lend itself to the image.
For this, there are two technical parameters on which to influence: the focal length, playing on the phenomenon of crushing of perspectives, the size of the area of sharpness and the aperture, marking the size of the area of sharpness and the intensity of the blur.
By opening the diaphragm to its maximum, we will reduce the area of sharpness and we will also accentuate the intensity of the blur. So, with a long focal length like 100mm and a large aperture, you are guaranteed to have a marked and homogeneous background blur….