Depth of Field and Camera Lenses

size of aperture

bigger the opening/smaller the number = shallower depth of field smaller opening/larger the number = deeper depth of field

distance from the subject to the lens

closer to the subject = shallower depth of field further from the subject = deeper depth of field

a short focal length (wide angle lens)

less light needs to enter the camera, therefore it can have an f-stop as low as 1.2 more potential for lens flares

the focal length of the lens

shorter focal length/wide angle lens = greater depth of field long focal length/telephoto lens = shallower depth of field

depth of field

the area in which objects of varying distances remain in focus

a long focal length (telephoto lens)

the more light needs to enter the camera, therefore it can only produce an larger f-stop

reciprocity

when the ISO/gain balances out with the shutter speed, creating a well-exposed picture

normal lens

-50mm- Hollywood calls it a "Jack Lord" -approximates normal human vision -relationships in 2-space are maintained -things in the background will appear as the actual distance away

wide angle lens

-5mm-40mm- stretches perceived distance -things closer to the center of the lens are large and distorted -easier for following action -more things at varying distances will be in focus (greater DOF) -the things in the background will seem farther away than they actually are

zoom lens

-can vary their fields of view by zooming in or out -the more you zoom in, the more telephoto (longer) your lens becomes -the more you zoom out, the wider (shorter) the lens becomes

prime lens

-cant change focal length -allow for larger maximum aperture (lower f-stop number)

telephoto lens

-long focal length 75-400mm -compresses space so things feel closer together -relationships in 2-space collapse in -harder to follow a person or object in motion -things in the background will seem abnormally large or close -great to convey a crowded space

the 4 things that effect DOF

1. Size of aperture 2. distance from the subject to the lens 3. the focal length of the lens 4. the size of the chip in the camera

a wider maximum aperture

more light can entire the camera