A photographer that is of professional and amateur is of amateur is because one of the major main spring that separate these two …it’s the technique of pre-visualization of professional, and without knowing the effect between the co-relation of Depth of field and aperture that set in the professional photos….amateur remains amateur
Its always this subtle different that’s makes the professional photos stand out, of course ,the professional origin from amateur and he/she is not born naturally professionally…so, how to train this pre-visualization technique then….and getting to know
Aperture, f-stops, f-numbers and depth of field(circle of confusion) are vital important.
Aperture is the physical opening of a lens that lets lights pass through to reach the sensor, the CCD or the film plane and is the quantitative measure of so call lens speed, and the degree to frame these wide opening dimension in numeric measurement are F-numbers. F-numbers derived from the focal length divided by the “effective aperture diameter”.
In general, ”F-stops” the terminology in photographic term, normally refers to the quantitative measure of the lens speed and is of how much light we allow to let allow to get in the CCD plane.
And ‘stops’ are unit used to quantify ratios of light or exposure, with one ‘stop’ meaning a factor of two(2 times of light to allow or to block).
One stop unit is also know as one EV unit. The greater the f-numbers,eg;f32 the smaller the aperture, and lesser light is allow to pass. Vice versa, the smallest the f-numbers eg;f2,the greatest the aperture, more light is allow to get through.
With these f-stops …what it does to the picture then…
Actually the aperture also effecting the control sharpness of the foreground and background from that particular focus point, and secondly, given the timing of the day, when the environment lighting getting darker, with wider aperture opening, it just need more lights to drop in…and actually professional photographer love to work in such situation, wider open aperture and relatively permitted faster speed, especially in street photography or photojournalism, and perhaps in a almost sun setting situation, expect the unexpected to happen.
Vice versa with all the strongest bright light, when maximum smallest f-stops could be used ,and with the ease of help of sharp focal plane, relatively sharpness through out the entire CCD plane, all possible could be captured without much worrying of the focusing, especially this happen during a chaotic situation, and fire off the speed and how fast the card can write your image is then crucial, while setting the format in JPG might help to write faster… RAW and TIFF write slower, hence may be a lot of the continuous action are not being capture….
Bruce L Davidson, a magnum agency American photographer, his photographs notably those taken in Harlem, New York City, have been widely exhibited and published and he is known for photographing communities usually hostile to outsiders, and look at the clever use of DOF (depth of field) to illustrate his theme of each photo…..