Optics is probably the most important part of any professional camera. Optical quality is assessed by the resolution, depth of field and the degree of presence of various artifacts such violation of sharpness. In particular, poor optics can be immediately identified by the halo on the contours of objects with different lighting, the contours obtained colored purple and yellow stripes. This is called aberration distortions. To eliminate these distortions and obtain high image quality using the most modern materials and advanced technology, resulting in such optics is sometimes much more expensive than the professional camera. Another requirement of a professional photo equipment – availability of fast and precise autofocus. This option is of particular importance when shooting a moving object, the dynamic scenes reportage and conducting surveys.
Professional cameras differ in a smooth and powerful AF drive, reducing vibration and noise when focusing. An important factor is the speed burst, ie the ability to camera when you press the shutter button to make the maximum number of snapshots at regular intervals. This requires, for example, when shooting the finish sprint race, when the second delay can cost you a photographer quality footage. In professional cameras necessarily present organized system of noise reduction image. "Noise" – a small colored blotches, which are especially noticeable on a black background and lead to a lowering of contrast and poor impressions of the picture. Particularly acute effect of "noise" appears when shooting subjects in low light, where it is necessary use a long exposure.