Bigger Sensors, Blurrier Backgrounds
A mobile phone might advertise that it comes with a large aperture lens, like an f/2, which means that the aperture (think of it like the eyelid of the lens) can open wide. But unlike a large aperture lens on a DSLR camera, which can provide more apparent background blur – also known as bokeh – it’s near impossible to get the same effect on a mobile phone.
This is because depth of field is affected by magnification, so the larger the sensor, the more the background can be blurred, leading to that dreamy outof-focus look in portraits. This is why it’s difficult to achieve the same effect with smartphones, which have small sensors.
But wide aperture lenses are also known as fast lenses, because they help the sensor capture more light at slower shutter speeds by letting more light in. So while that f/2 lens might not get you dreamy bokeh, it will help you shoot at faster speeds in low-light, reducing the chances of camera blur.