- September 21, 2011 at 4:37 am #42745
The prime function of the lens is to focus the light onto the sensor.
Seems simple enough. Set the camera on auto focus and let the camera do it all. Set the camera on manual and you can have some control over what is ‘in focus' and what is not.
Unfortunately, for any lens, there is only ever one plane that will be sharp. Things will get progressively fuzzier as we venture either side of this plane.
We can control how much fuzziness and how quickly it happens by altering the aperture (see ‘A' is for aperture). Because our camera, printers, screen and even our own eye can't distinguish absolute focus all that well (yet) some of the bits that are only very slightly out of focus can appear nice and sharp, especially if you stand back a bit.
We call this distance over which objects will appear relatively sharp the ‘depth of field' (DoF). The DoF depends on 3 things: the aperture, the focal length of the lens and the distance from the subject. You can alter any of these things and see the effect it has.
In addition to the optical aspects of fucussing, we also have an aethetic and perceptive side to consider.
The idea that we might need to focus someone's attention when they are viewing the photograph is often considered by photographers when composing and processing.
There are many ways this can be done including the use of colour, tone, geometric compositional elements such as lines and shapes. Dodging and burning is also a useful tool in the focussing of someones attention.
I'm sure you have heard the expression ‘Lovely depth of field' or ‘that image is really sharp'.
Every photograph displays a DoF. Its how it is used that counts.
And ‘sharp' isn't everything, nor is it what it is cracked up to be.
The ability to focus is important in any image. That doesn't mean that everything has to be in absolute focus. Once you take control, you'll be amazed at how creative you can be.
- September 21, 2011 at 11:09 am #46735
- September 21, 2011 at 11:09 am #68547
- September 21, 2011 at 3:34 pm #46736
- September 21, 2011 at 3:34 pm #68548
- September 21, 2011 at 4:55 pm #46737
- September 21, 2011 at 4:55 pm #68549
- September 22, 2011 at 6:15 am #46738
- September 22, 2011 at 6:15 am #68550
- September 22, 2011 at 6:35 am #46739
- September 22, 2011 at 6:35 am #68551
- September 22, 2011 at 2:17 pm #46740
- September 22, 2011 at 2:17 pm #68552
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