Now technology allows us to have a mini camera in our pocket always ready to use. Although new smartphones are increasingly performing from a photographic point of view, nothing can match the quality of the Reflex.
They are divided, as well as for different levels of cost, especially by type of sensor they possess. The sensor is the part of the camera that captures the image impressed by the light that is passed through the lens.
The Full Frame sensor and the APS-c sensor differ in their size. The first one has dimensions 36mm x 24mm. The second has dimensions 23mm x 16 mm.
But where is the difference in the practice of using a camera?
The difference lies in the "crop factor".
If we took the same photo, with the same lens but with two cameras, a Full Frame and a APS-C, we realize that the photo made with the smallest sensor will be "Zoom-in" compared to the photo made with the FF machine.
Photo made with Reflex with Aps-c sensor. It has a x 1.6 zoom compared to the next photo, taken with FF machine.
Photo taken with FF machine.
Both photos were taken at the same focal length of 35 mm.
A 35 mm lens mounted on a Full Frame machine will produce full-frame photos, that is a photo that really reflects a focal length of 35 mm.
Instead if the same lens is mounted on a Reflex with Aps-C sensor, to know the real focal length (keeping in mind the crop factor) that will result in the photo, we must multiply the focal length of the lens (35mm) for 1.6 . So if we are shooting for example with a Canon 1300D or with a Nikon D3300, with a 35 mm lens, the photos that will produce, correspond to a 50 mm lens mounted on a Full Frame.
Another big difference between the Reflex FF and Aps-C, is the sensitivity to ISO. The Iso value represents the sensitivity of the machine to the light that surrounds us.
Often when we are in low light situations such as in buildings, or in night situations, we are forced to increase this value which makes it easier to set a shot without having to decrease the values of the shutter speed. Doing so avoids producing blurred photos (usually the blur is avoided according to a shutter speed 1/120 - 1/200 upwards). However, the more this value is increased, the more the so-called "noise" can be present in the photo, ie the "grain" that is being formed in the picture and which diminishes its quality. Reflex FF machines can withstand higher ISO values than Aps-c machines.
Below is an example (exaggerated) of what the noise produces in a photo.
(photo without noise)
(photo with noise)
So if with the Reflex Full Frame we have shots that will be real focal lengths, if it has a better ISO resistance why we should choose Reflex with Aps-c sensor? Well ... they are "cheaper".