Lens aperture is the size of the opening that lets the light into the camera. A larger opening lets in more light and a smaller opening lets in less light. A larger opening requires a slower shutter speed while a smaller opening requires a faster shutter speed.
The science of optics is very precise, but the science of film and camera sensors is less so. The results of this are many:
1. It's the lens system that makes the biggest difference in the quality of the picture you get, not the camera body. A film point and shooter would never do the job an SLR would in the same situation just because of the lens differences. This also applies to digital photography.
2. If you have a solid understanding of how your camera works; especially aperture and shutter speed; you can do some very cool things.
3. Regardless of whether you use film or digital, the science of optics and aperture/shutter speed is a constant.
4. Film speed (ISO) is not as sensitive as we think it is, and therefore not as important as other factors. For example, you can put a roll of ISO 200 in your camera and set the camera for ISO 400 and still be hard pressed to notice in most situations.
What does all this mean? It means that when you look for a camera to take great pictures every time, the list of features in order of importance are:
1. a good lens system
2. a good body (aperture and shutter control)
3. film speed control (ISO)
The first feature is often compromised for the sake of cost and many folks opt for a point and shooter. Point and shooters can have good optical components, but they do have their limits in very bright and very dark light situations. That's why the Prosumer type cameras like the Sony line up became very popular. The market trend now is that more and more consumers are buying DSLR's becuase of the superior pictures and today's prices make them affordable to more people.
2006-12-23 01:33:20
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answer #1
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answered by Anonymous
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Although available on digital camers it is easier to understand exposure control as they were developed for film.
On 35mm film camers there are two main adjustments to adjust exposure. Shutter Speed and F-stop(also called aperture) F-stop is a numeric scale to indicate aperture size. Aperture is an an adjustable opening to control the ammount of light passing through the lens
Shutter speeds are in fractions of a second and each adjustment would be 2x or 1/2 time the value depending on which way you moved the knob.
so typical shutter speeds are :
1/60, 1/125,1/250,1/500 & 1/1000 (just the denominators would be on the shutter speed knob)
So shutter adjustment adjusts the time the shutter is open .
Large number (1000) = 1/1000of a second the quickest shutter speed and the smallest exposure time.
Small number (60) = 1/60th of second much slower and a longer exposure time.
So you can control the amount of light by adjusting exposure.
If it is too dark then slow the exposure to hold the shutter open longer. To Bright raise the shutter speed and reduce the time light would expose the film.
F-Stop or Aperture is the second means of exposure control. It is done by adjusting an iris in the lens which works in a similar fashon to your eye. The Aperture opens and closes inside the lens to adjust the amount of light which passes through.
There are numeric markings on the F-stop which typically range in values from f1.4 to f16 and like the shutter speed control adjacent values are 2x or 1/2 the previous value.
Under stand for a moment that light intensity on a surface depends on its distance from a ligh source.. There is an inverse squared relationship between light intensity and distance . So if you double the distance from the light source you will have 1/4 the light brightness
So the markings of F-stop are alternating doubles of 1 & 1.4
which correspond to doubling of square area or halfing of light intensity.
F# Fsquared
1 1 Largest Apeture opening Most light entering
1.4 2
2 4
2.8 8
4 16
5.6 32
8 64
11 128 Smallest Apeture opening Least light entering
Using A combination of f-stops and shutter speeds one may double exposure by one means (slowing shutter speed) and half exposure by another (increasing f-stop number from 2.8 to 4)
This gives the photographer a wide range of equivalent exposure settings to properly expose the film with equal quantities of light.. You will also find EV settings which adjust the overall brightness of your picture.
WHY??? Creative control
The f-Stop controls light entering the camera AND depth of field.
Depth of field is how much is in focus infront of AND behind you subject focused on.
Shutter speed determines wether a moving subject will be blurred by its motions or crisply captured.
On Automatic exposure film AND digital cameras the electronics use one setting (Shutter or Apeture ) as the priority setting (selected by the photographer) and automatically adjust the other for proper exposure.
So you decide you want to photgraph race cars on a bright day you need a fast shutter speed. The camera adjusts the f-stop automatically
Same when you want an indoor shot of someone blowing out candles. You set a slow shutter speed to let in the maximum duration of light. The apeture is again automatically adjusted.
But if you wanted depth of field control and the camera is automatically adjusting f-Stop allowing you only shutter speed(exposure) control. You would understand the the exposure relationships above and use a Candle setting (slow shutter) out side in bright sun will cause the apeture to close down correcting the exposure and increasing the depth of field.
2006-12-23 01:45:40
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answer #2
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answered by MarkG 7
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Well.....INSIDE your camera is this thing they call an aperature....
It OPENS AND CLOSES according to how much light is coming into the camera.....It is also known as an IRIS....Your eyeball has an IRIS, It's that colored part of your eye, that opens and closes. It adjusts your eyes to daytime/outside to nightime vision so you can see anything, anytime, anyplace....It's important to have it.....
NOW.....night-time camera work NEEDS an OPEN iris/aperature....and SLOW SHUTTER speed to make a VISIBLE picture....Daytime needs less opening and faster shutter because there is so much light available.......
When the aperature is MORE OPEN you get a lot more VERSATILITY in "Field of Depth" ......that means you can focus on your Subject and Blur the BACKGROUND (which makes Good ART)
When it's closed more....you can get the Cheerleaders 10 feet from you, the football team 30 yards from you, the scoreboard 50 yards from you all on one shot! That's also known as a "tight" shot......
If you're working with Digital.....the CCD sensitivity is important....0.8 lux or lumen sensitivity is better than 1.2 lux or lumens....Better at nightime shots.....but they also are a tad noisier.
So KNOW WHAT YOU'RE REALLY GOING TO USE THIS CAMERA FOR!! More indoor work? More Night Work? ONLY DAYTIME/Sunshine stuff?
Select the CCD sensitivity according to your needs first and foremost....Then Aperature will be properly set for the Real World use of that specific CCD....(unless you buy your own lenses)
2006-12-23 01:13:03
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answer #3
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answered by reggieman 6
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Flickr also has this information, though individual users can turn it off so it doesn't appear. When you are looking at a photo there is a link in the right column called something like more info.
2016-05-23 01:34:25
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answer #4
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answered by ? 4
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the smaller the aperture, the sharper the image, but the more light it needs, therefore slower shutter speed. and vice versa.
2006-12-23 00:47:49
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answer #5
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answered by David B 6
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draw two circles one inside the other the measurement from the edge of the inside one to the edge of the outer circle that is the numbers you get for the aperture the bigger the number the farther the shutter has to open and vice versa
2006-12-23 00:59:04
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answer #6
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answered by remy 3
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This might help:
http://en.wikipedia.org/wiki/Camera
2006-12-23 00:52:21
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answer #7
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answered by eeaglenest 3
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Here's all you'll ever need to know about digicams:
http://www.stevesforums.com/forums/
2006-12-23 00:52:20
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answer #8
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answered by Mr. Peachy® 7
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difficult task. lookup in search engines like google. that will help!
2015-03-29 17:15:25
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answer #9
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answered by kimberly 2
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