Cream Of Tartar In Juice

Depth of Field Aperture priority

The depth of field is one of the basic principles of photography . When allows you to focus an image, only a specific subject will be really focused. Anything that is in front of or behind the object will be phased out of focus, the areas closest to the plane of maintaining a sharp focus are the acceptable depth of field.

There are two factors that influence the depth of field: Aperture 1.1



The amount of light reaching the sensor is determined by the diaphragm and is designated with a value of "f" (eg, f2 .8, F16, F32 ...).
High values \u200b\u200b(eg, F16, F32) correspond to apertures and shutter speeds then longer and greater depth of field.
Low values \u200b\u200b(eg f2.8, f4) correspond to apertures and shutter speeds then shorter and shorter depth of field, ie aperture priority f/2.8






f/11



The images above show clearly that the first was taken with an f 2.8 aperture in fact both the foreground and background are blurred out, but in the second image (f 11 ) everything is in focus.
Close the diaphragm to obtain a large depth of field, however, has two disadvantages: 1) the amount of light reaching the sensor is decreased, and therefore require slow shutter speeds 2) the image quality is worsened by the diffraction, a phenomenon that becomes evident at smaller apertures. Focal Length 1.2



If you increase the focal length, keeping the camera-subject distance, depth of field becomes more limited.

50mm to 200mm f4.8 to f4.8



If you take a picture of a relatively large proportion will have more depth of field. For example, if you photograph a mountain at f5.6 you will have an extensive depth, but if you photograph a butterfly with the same aperture depth of field will be much reduced.

So we can summarize that ....

The depth of field is the area that once assicuratisi an acceptable focus, the frame will be sharp. The size or depth of this field is precisely determined by the value that is assigned to the diaphragm. In fact, using a short focal length (eg 35mm) and a small aperture (f11 then) you will get a maximum depth of field, so a total sharpness over the entire frame. If you take a long lens (like a 210mm) and an aperture wide open (f2.8) will create a shallow one that will lead to almost complete blurring of the background.

This scheme is summarized: