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Shooting On Manual


Many beginners and even some mid-range pros photograph using one of the automated settings for exposure. 

It works most of the time. I prefer shooting on manual but some are reluctant to use manual setting because they don't understand that relationship

between aperture, shutter and ISO. 

Actually, once you start using manual as a choice, it is hard to go back.

So the following is an attempt to explain the 

relationship and advantages of aperture, shutter speed and ISO!



THREE THINGS DETERMINE YOUR EXPOSURE and they all work together to give you an advantage or disadvantage.

• Your Aperture (measured in f stops)

• Your Shutter Speed

• Your ISO, a numerical measure of your camera's light sensitivity.




LIGHT METER READING = Shutter 25o/sec at f8 at ISO 100


 New Possible Settings at same exposure


Shutter: 125/sec   Aperture: F11  ISO: 100


The 125/sec lets in twice as much light as 250/sec.

But f11 lets in half the light as f8 and with the ISO the same, the first ands second examples have the same exposure EXCEPT that 125/sec does not stop as much action, and f11 renders more depth of field.


 Shutter: 500/sec  Aperture:F5.6  ISO: 100


The 500/sec at F8 lets means the shutter lets in half as much light as 250/sec but f5.6 lets in twice as much light as f8 and with the ISO the same, It is the same exposure as 250/sec at F8 EXCEPT  that 500/sec stops much more action but F5.6 has much less depth of field


Shutter: 1000/sec   Aperture: F5.6   ISO: 200


When you move your ISO setting from 100 to 200, it gives you exactly one more stop of light sensitivity. 

In this example, we used that extra stop of light by choosing a FASTER shutter speed to stop more action. The ISO gives you one additional stop to play with, but the faster shutter speed is one stop faster and lets in one stop less the amount of light.


DRAWBACK? ISO 200 has slightly more noise in digital and grain in film. The higher the number of your ISO the more noise or grain you can expected in your image.



Apertures control the light

coming through your camera lens.

Aperture means an opening. If you take the lens off of your camera and move the ring, you can see the aperture opening and closing. When working with the camera, the size of the opening (known as an f stop) determines how much light it throws onto your film or digital sensor. Each click stop represents one stop of more or less light. 

The aperture works a bit like what you do when you open the curtains in your home. It lets in more or less light dependent upon how far you shut or open the curtain.

Aperture is ONE way of controlling light going into your camera.

Aperture has another important function other than controlling light


The smaller the aperture hole, the more DEPTH OF FIELD one gets in return. Because it is an equation, one may think that the f22 signifies a larger opening. The opposite is true.


But if you want, you CAN think of aperture numbers as a DEPTH OF FIELD measurement.


The bigger the aperture number the more depth of field 

That simply means the an aperture of f22 has a better chance of keeping IN FOCUS an extreme foreground and background. 


So a word of warning regarding depth of field and 

your choice of lens.

The photo below is shot with a wide-angle lens. It is much more adaptable to producing depth of field than a telephoto lens, which tends to compress your image.

Using a small aperture with a telephoto lens (especially 200 mm and above) is a waste of time. F8 or wider is usually a good aperture. If you want to take advantage of minimal depth of field to blur out the background shoot wide-open (like f2.8) and get closer to your subject (great for portraiture).

 Above, foreground and background being in focus is no accident. A carefully planned photo like this demands a small aperture, like f16 or f22. 

The reverse if also true. To blur a background, a wide-open aperture does the job as seen below in the image of a Big Horn in snow, shot with a telephoto at f2.8.


In the above photo, the background is blurry  because it was photographed with a telephoto lens wide open (F2.8)


The shutter opens and closes for various lengths of time.


 Simply stated, it controls the light coming into your camera by using time length.


Working with the time value of a shutter one has to realize that a longer exposure lets in more light AND also sees more movement, your aperture controls and counteracts light by making the hole in your lens bigger or smaller. They work together so you can do a variety of photographic duties while maintaining the same exposure. 

For example, given the same exposure value, a photograph 

at 500 (shutter speed) at f8 (aperture) will stop most action and have reasonable depth of field. You can also photograph

a sports event at 2000/sec at f4 and get the same exposure,

but stop very fast action with less depth of field.


Here's a third component that works interchangeably with your aperture and shutter speed.

Your light meter gives you an idea of how much light should strike your sensor or film.


In your camera, too much light and you are overexposed. Not enough light you are underexposed. 

Your light meter tries to give you that sweet spot.

The cool thing is that exposure in your camera is set up 

in equal commodities, or stops. All click stops in your shutter speeds, apertures and ISO are measures of one stop..

Each stop either doubles or halves the amount of light allowed  into your camera. So a shutter speed of 500/sec allows half the amount of light at a shutter speed of 25o/sec. 125/sec allows twice as much light to enter you camera as 250. Those are one-stop differences.

ISO 200 is twice as light sensitive (one stop) as ISO 100.

Beware: It gets tricky when you talk about stops in a camera.

As an example: The difference between ISO 100 and 1600

is not 16 stops and it is not 5.

ISO 100-200-400-800-1600

It is 4 stops. Above, each red dash represents your change

in stops.

If you just think of what each exposures component does, 

photography becomes easier. 

Shutter Speeds


Each stop allows either twice the amount of light or half

and that is a one stop different. It makes sense that a faster shutter speed lets in less light and that a slower shutter speed let is more light.


If you get hung up on numbers you have to realize the apertures are measured in an equation.


Specifically, the “f” in your aperture value stands for Focal Length. Your aperture value is determined by the lens' focal length divided by the diameter of the aperture opening. Thus, a 100mm focal length lens with an aperture opening of 50mm would result in an aperture value of 2.


F2, f2.8, f4, f5.6, f8, f11, f16, f22, f32

F2 lets in one stop more light than does f 2.8 because

F2 is a larger aperture than F2.8. The difference between 

f2 and f 4 is 2 stops with f4 having the smaller aperture.

But f4 has more depth of field, meaning there is a wider

area in the scene that'll be in focus that f2.

It is not science, but if you view the increased aperture numbers in a friendly way, the higher number give more depth of field.



Higher numbers have more light sensitivity but also introduce 

more noise in digital and grain in film.

The difference between ISO 100 and ISO 200 in one stop. 

ISO 200 is one stop more sensitive that ISO 100. 

My favorite settings?

F8 is widely thought to be a perfect apertures. Clarity is supposed to be maximum around F8. 

My favorite ISO is 100 but I will venture to 400 and, perhaps 800 for night photos. I have a lens that will shoot wide open at F1.2. That is 2 stops faster than F2 and works for me when I do single exposure milky way photos. That way I can photography at a lower ISO. 

My favorite shutter speed is whatever works for the situation.

I photograph a lot with a 16-35 wide angle lens. I prefer using a tripod, but will--at times-- handhold as slow as 60/sec. 

Be aware that the longer the lens (like a 200 mm telephoto) shows more camera and hand movement because of  magnification. Most of my telephoto work is with the aid of a tripod and a delayed shutter release. 

A general rule is that your hand-held shutter speed should equal lens' focal length. So a 200mm lens should be

at least 200/sec if you hand hold. 

But a 600mm lens should be used with tripod no matter what.












































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