Aperture - Most lenses contain a diaphragm, a thin light-blocking plate or interleaving set of adjustable plates. The diaphragm contains a small hole, the aperture, which is adjustable in size and allows the photographer to control the amount of light entering the camera. Apertures are indicated by the f stop value, which is a relative value and does not indicate the actual size of the aperture hole.
WIDE APERTURE:
![140091567_41e18a046c_m.jpg]()
50mm @ f/1.4
MID APERTURE:
![140091633_effbcc49b4_m.jpg]()
50mm @ f/8
SMALL APERTURE:
![140091657_d712f8ad5d_m.jpg]()
50mm @ f/16
The higher the value of the stop (f/16, f/22), the smaller the hole through which light passes, the clearer the overall image is.
The lower the value of the stop (f/2.8, f/1.4), the wider the hole is, the shallower the depth of field (defined later.)
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Shutter Speed - The precisely-calibrated amount of time that a camera shutter stays open, usually measured in fractions of a second.
The shutter speed and the lens aperture are the principal forms of control that a photographer has over the amount of light which hits the film or image sensor of a camera. To be more accurate, this should really be known as “shutter time,” but “shutter speed” is the traditional name.
QUICK SHUTTER
![128912886_31c61461af_m.jpg]()
32mm @ 1/1000 sec (f/5.6)
MID SHUTTER
![137003972_d32ce5f116_m.jpg]()
80mm @ 1/64 sec (f/5.6)
SLOW SHUTTER
![168695045_5f318caaaf_m.jpg]()
28mm @ 2" (2 seconds) (f/2.8)
Quick shutter speed allows for capturing motion in a still shot, and slow shutter speed allows for motion to be captured.
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Aperture Priority Mode - Also “aperture preferred system.” A programmed automatic exposure setting on most automated SLRs. In this mode the photographer specifies the desired aperture and the camera automatically sets an appropriate shutter speed based on information from its internal light meter.
Canon, Pentax and Contax abbreviate aperture priority as “Av” for “aperture value.” Nikon and Minolta abbreviate it as simply “A.”
Shutter Speed Priority Mode - Also “shutter preferred system.” A programmed automatic exposure setting on most automated SLRs. In this mode the photographer specifies the desired shutter speed and the camera automatically sets an appropriate lens aperture based on information from its internal light meter.
Confusingly, Canon, Pentax and Contax abbreviate shutter priority as “Tv” for “time value.” Nikon and Minolta abbreviate it as simply “S.”
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Depth of Field - (DOF).
Very simply the distance range of acceptable focus in front of your lens.
When you focus your camera on a given point there is a range in front of the point and behind that point which is also in acceptable focus. If this range is very narrow then you have very shallow depth of field - only the plane at the focus point will be in focus and everything else will be blurry. If you have deep depth of field then much more of the image will be in acceptable focus.
Depth of field is determined by a number of factors. The three key factors governing depth of field on a given camera are the aperture and focal length of the lens and the subject distance.
Aperture.
The larger the aperture (smaller the f stop number) then the smaller the depth of field and vice versa. Pinhole cameras, which have tiny holes rather than lenses, have a near infinite deep depth of field.
Focal length.
Lenses with short focal lengths (wide angle lenses) have wider depths of field available and lenses with long focal lengths (telephoto lenses) have shallower depths of field available. This is generally a good thing. If you’re using a really wide lens for landscape shots you’ll be able to get huge areas of scene in sharp focus. But if you’re using a really long telephoto lens for bird photography then your depth of field will be really shallow and you’ll be able to isolate the bird in the landscape nicely.
![69156375_854591ca14_m.jpg]()
Short focal length - wider DOF (more in focus)
![140559926_5a9e135b80_m.jpg]()
Long focal length - shallower DOF (less in focus)
Subject distance.
Finally, the distance from the lens to the subject also affects depth of field. If you’re really close to your subject, such as with macro photography, then depth of field will be shallow. But if you’re taking a photo of something that’s a long way away then your depth of field will be deeper.
One other point is that the size of a camera’s image area also dictates the depth of field. A camera with a large image area - say a medium-format or large-format camera - is capable of a much more shallow depth of field than a camera with a smaller image area. This is why consumer digital cameras, which have tiny image sensors, have such deep depth of field.
It should also be noted that this is a very non-technical description of what depth of field is all about. To be more accurate you need to go into a lot of math and consider the definition of the circle of confusion and the print size and so on. But the simplified aspects above are adequate to get a grasp of how to control depth of field adequately to make your photos look the way you want them to.
Depth of field is sometimes called depth of focus, but that is not correct. Depth of focus would be the tiny range of acceptable focus behind the lens at the focal plane itself.
Add additional tips below. Definitions from PhotoNotes.org
WIDE APERTURE:
50mm @ f/1.4
MID APERTURE:
50mm @ f/8
SMALL APERTURE:
50mm @ f/16
The higher the value of the stop (f/16, f/22), the smaller the hole through which light passes, the clearer the overall image is.
The lower the value of the stop (f/2.8, f/1.4), the wider the hole is, the shallower the depth of field (defined later.)
-------------------------------------------------------------
Shutter Speed - The precisely-calibrated amount of time that a camera shutter stays open, usually measured in fractions of a second.
The shutter speed and the lens aperture are the principal forms of control that a photographer has over the amount of light which hits the film or image sensor of a camera. To be more accurate, this should really be known as “shutter time,” but “shutter speed” is the traditional name.
QUICK SHUTTER
32mm @ 1/1000 sec (f/5.6)
MID SHUTTER
80mm @ 1/64 sec (f/5.6)
SLOW SHUTTER
28mm @ 2" (2 seconds) (f/2.8)
Quick shutter speed allows for capturing motion in a still shot, and slow shutter speed allows for motion to be captured.
-------------------------------------------------------------
Aperture Priority Mode - Also “aperture preferred system.” A programmed automatic exposure setting on most automated SLRs. In this mode the photographer specifies the desired aperture and the camera automatically sets an appropriate shutter speed based on information from its internal light meter.
Canon, Pentax and Contax abbreviate aperture priority as “Av” for “aperture value.” Nikon and Minolta abbreviate it as simply “A.”
Shutter Speed Priority Mode - Also “shutter preferred system.” A programmed automatic exposure setting on most automated SLRs. In this mode the photographer specifies the desired shutter speed and the camera automatically sets an appropriate lens aperture based on information from its internal light meter.
Confusingly, Canon, Pentax and Contax abbreviate shutter priority as “Tv” for “time value.” Nikon and Minolta abbreviate it as simply “S.”
-------------------------------------------------------------
Depth of Field - (DOF).
Very simply the distance range of acceptable focus in front of your lens.
When you focus your camera on a given point there is a range in front of the point and behind that point which is also in acceptable focus. If this range is very narrow then you have very shallow depth of field - only the plane at the focus point will be in focus and everything else will be blurry. If you have deep depth of field then much more of the image will be in acceptable focus.
Examples:
![140091567_41e18a046c_m.jpg]()
Shallow DOF
![140091657_d712f8ad5d_m.jpg]()
Deep DOF
Shallow DOF
Deep DOF
Depth of field is determined by a number of factors. The three key factors governing depth of field on a given camera are the aperture and focal length of the lens and the subject distance.
Aperture.
The larger the aperture (smaller the f stop number) then the smaller the depth of field and vice versa. Pinhole cameras, which have tiny holes rather than lenses, have a near infinite deep depth of field.
Focal length.
Lenses with short focal lengths (wide angle lenses) have wider depths of field available and lenses with long focal lengths (telephoto lenses) have shallower depths of field available. This is generally a good thing. If you’re using a really wide lens for landscape shots you’ll be able to get huge areas of scene in sharp focus. But if you’re using a really long telephoto lens for bird photography then your depth of field will be really shallow and you’ll be able to isolate the bird in the landscape nicely.
Short focal length - wider DOF (more in focus)
Long focal length - shallower DOF (less in focus)
Subject distance.
Finally, the distance from the lens to the subject also affects depth of field. If you’re really close to your subject, such as with macro photography, then depth of field will be shallow. But if you’re taking a photo of something that’s a long way away then your depth of field will be deeper.
One other point is that the size of a camera’s image area also dictates the depth of field. A camera with a large image area - say a medium-format or large-format camera - is capable of a much more shallow depth of field than a camera with a smaller image area. This is why consumer digital cameras, which have tiny image sensors, have such deep depth of field.
It should also be noted that this is a very non-technical description of what depth of field is all about. To be more accurate you need to go into a lot of math and consider the definition of the circle of confusion and the print size and so on. But the simplified aspects above are adequate to get a grasp of how to control depth of field adequately to make your photos look the way you want them to.
Depth of field is sometimes called depth of focus, but that is not correct. Depth of focus would be the tiny range of acceptable focus behind the lens at the focal plane itself.
Add additional tips below. Definitions from PhotoNotes.org
