I Have a Camera -- Now What?

No matter how sophisticated the camera, the photographer is still the one that makes the picture.- Doug  Bartlow

The first camera I ever used was an old Ricoh range finder that my father bought in the mid 1960’s.  Everything on it was manual: exposure, focusing and frame advancement.  All-in-all, it wasn’t too hard to use but I still managed to take a lot of bad pictures.   

The first camera i bought was a Nikon FM. This was Nikon’s semi-pro single lens reflex (SLR)35mm camera line and again everything was manual.  This camera saw me through college and my first professional jobs. It was nothing fancy, but I was able to make a living with it.   

This was when I learned that it wasn’t the camera that was important but how I used it.  Yes, I lusted after the Nikon F2 because it had a better light meter and the film motor-drive shot faster (and just looked cooler).  However, what my professors and co-workers drilled into me was I needed to learn to take consistently good exposures and learn how to “see” the photograph in my mind before I snapped the shutter.  

With today’s equipment the only thing the camera can’t do automatically is point itself at the subject. The photographer still needs to do this step.  With  multiple auto exposure modes, 51 point auto focus and pre-defined scene selections from autumn colors to pet portrait, taking pictures has gotten a whole lot easier. Truth be told, I shoot in program mode (P) about 80% of the time.  It allows me to concentrate on the image and not the technical aspects. However, I do regularly make adjustments to the exposure settings to ensure I get the image I want.  

In order to make sure the camera will do what you want, you need to understand the basics of how a camera works.  The first step is understanding how the different settings on the camera work together to create a proper exposure.  

Shutter speed, lens aperture (focal stop or f-stop), and sensitivity to light (ISO) all need to be adjusted correctly to get the proper exposure.  Exposure is like trying to perfectly fill a glass with water, right to the brim. The glass will only hold an exact amount of water.  Less will be under filled (under exposed) and too much will run over (over exposed).

 The size of the glass is the same as the sensitivity to light.  In photography this is referred to as ISO.  The higher the ISO number the more sensitive the imager chip is to light, thus less light is needed to get a correct exposure. A larger “glass” equals a lower ISO number.

How far open you turn the “faucet’ is the aperture (f-stop).  Simply put, the aperture is the opening in the lens that lets light through.  The  f-number is the focal length of the lens divided by the size (diameter) of the aperture.  This gives you the f-stop number.  The larger the f-stop number the smaller the size of the aperture (I know it seems backwards that a lager number is actually smaller).  

How long you let the “water’ run is the shutter speed.  This one is pretty simple.  Shutter speeds are given in either whole seconds or fractions of a second (2 sec, 1 sec, 1/2 sec, 1/30th, 1/60th, etc).  

In order for the exposure to be correct, or the “glass” to be filled, all three elements must work together.  The larger the “glass” (ISO) the more “water” you need.  The more you open the “faucet” (aperture) the shorter time (shutter speed) you need to have the “water” on to fill the glass.  

Each basic adjustment you make in one of the settings is equal to the others. This is referred to as a “stop” . Basic shutter speeds are adjusted by reducing in half (or close): 1/30th, 1/60th, 1/125, 1/250, 1/500, etc.  Each aperture setting lets in half the light of the previous: f/2.8, 4, 5.6, 8, 11, 16, etc.  Each adjustment in ISO makes the sensor double the sensitivity: ISO 100, 200, 400, 800, etc.  For now, ignore the “in-between” adjustments newer cameras can make.  It will only confuse what you are trying to learn.

What this means is if I have a correct exposure at ISO 200, 1/125th and f/8, and I move the shutter to 1/250th (shorter time the shutter is open) I need to either change the aperture to f/5.6 (let more light in) OR move the ISO to 400 (make the sensor more sensitive).  A one stop change in shutter speed must be matched with a one stop change in either aperture or ISO.  

Fortunately, our cameras will tell us when we have it right.  Most cameras have multiple exposure modes: Auto, Program (P), Aperture Priority (P), Shutter Priority (S), Manual (M).  Some have specialty settings but I’m going to ignore those for now.  Each setting has a specific use, depending on what you are trying to achieve. 

About now you’re probably wondering why you should care about these things since the camera will do it all for you. While there can be many different settings to get a good exposure, only one will yield the correct setting for the image you want to capture.

Unfortunately, as smart as today’s cameras are, they are still pretty dumb.  The camera can’t anticipate what you want it to do unless you give it some guidance.  By understanding these basic principles, I can still use my 1906 box camera and get well exposed images.

In the next post I’ll discuss shutter speeds and how to use them to get the shot you want. Then I’ll move on to aperture and ISO adjustments.  In the mean time, put your camera on manual exposure and go out and give it a try. If you mess-up, just delete the pictures and don’t tell anyone.