Exposure

[michaelused]

I keep hearing about exposure, but I'm not quite understanding what it is. I have an olympus e-410 so how do I work with exposure with it? Any help would be great

 

[Joefbs]

[h=5][/h]

The process of light hitting the surface of some light-sensitive material, such as film or photographic paper or a digital image sensor. Hopefully it goes without saying that controlling exposure is critical to good photography.
At its most basic, exposure in a camera is determined by two settings - the shutter speed and the lens aperture. The shutter speed (more accurately shutter time) is the length of time the camera shutter remains open, allowing light to enter the camera and expose the film or image sensor. The aperture is the size of the adjustable lens diaphragm, which can let in varying amounts of light.
Some cameras are fully automated and exposure settings are determined mainly or wholly by an internal computer, which makes its decisions on the basis of readings from an internal light meter built into the camera body. Other cameras are manual in operation - the photographer must set the exposure settings by hand, perhaps assisted by an internal light meter.
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[SnappingShark]

It's the amount of light reaching the sensor on your camera (or film, if you shoot with film) - and a correct exposure (technically) is determined by shutter speed, lens aperture and available light.


AFAIK - but I may have gotten it all wrong - it's happened before!

 

[Joefbs]

That's the Definition of Exposure. Basically the Brightness or Darkness of the photograph.

 

[KmH]

Camera Exposure: Aperture, ISO & Shutter Speed

A key concept for controlling exposure is known as a stop.

A 'stop' is a doubling (2x) or a halving (0.5x) of the amount of light and a stop is a fundamental photography concept.
A stop change in exposure can also apply to shutter speed and ISO.

Since exposure is a triad of adjustments (shutter speed, ISO, lens aperture) you can change 1, 2 or all 3 of the triad settings.

If you want 1 more stop of exposure (brighter) you can adjust just one of the 3 by 1 more stop.
Or, you can change 2 of the 3 by 1/2 more stop each for a net gain of 1 stop of exposure.
Or, you can adjust all 3 by 1/3 more stop for a net gain of 1 stop of exposure.

You can also change the triad of settings and have no change in the exposure.
If you change 1 of the 3 settings by 1 stop more exposure and change a 2nd setting by 1 stop less exposure the net change is zero.
Suppose you subtracted a stop of shutter speed to help stop subject motion, you could add a stop of lens aperture to keep the exposure the same. However, adding a stop of aperture will also affect the total DoF by a small amount. So, if you don't want the DoF to change you would add a stop of ISO instead, however, adding a stop of ISO will increase by some amount the image noise in the photo.

Note: DSLR cameras are set by default to adjust the exposure settings in 1/3 stop increments.
Most DSLR cameras let you change that to 1/2 stop or 1 stop increments.
However, the advantage of 1/3 stop step increments is more precise control of exposure.

 

[TCampbell]

This video posted some time back by Matthew Gore may be helpful to you:

 

[PWhite214]

For a quick but concise tutorial on exposure, check out Cambridge in Color, Camera Exposure: Aperture, ISO & Shutter Speed. For more depth, read Bryan Peterson's book "Understanding Exposure". You might find it in your local library. While getting the correct exposure is essential, using your cameras controls for a creativie may not be so intuitive.

There is so much information on Cambridge, one can spend hours learning.

Another book I really like is "Composition: From Snapshots to Great Shots" by Laurie Excell. Her exercises will help gain a knowledge of your camera and accessories.

Good luck and have fun,

Phil

 

[michaelused]

Thanks everyone for the responses. I'll try to look for the books you is mentioned at my library. I tried in ding books at a store called Barnes & nobles but there were all in the $30 to $40 range.

 

[PaintBrightStudios]

When someone asks... what are that photo's exposures? You basically answer the Shutter Speed, Aperture, and ISO settings used.

 

[dennybeall]

Many years ago (too many to say) my first photography teacher likened exposure to filling a bucket with water.
The bucket is X big and I can open the valve all the way and fill the bucket quickly or Open it a little and take longer to fill the bucket. In both cases the bucket gets filled with the same amount of water. Simplistic but symbolic......