Photography

June 28, 2014

I’m about to get my first DSLR (a D7000) and I don’t feel like I can justify spending serious money unless I have mastered the core concepts. I have a buddy who went to Cal Arts and taught me a lot many years ago, and even took me to the dark room to do some black and white stuff, but I need to refresh what I learned, learn even more, and then capture it. So here we go.

Basics

Photography seems to be all about one main concept: How much light is hitting the sensor (film). There are a couple of ways to control this. You can:

increase the amount of light that comes into the camera by increasing the size of the opening it comes in from
you can increase the time the opening stays open

The size of the opening is called a camera’s aperture, or an f-stop. Smaller apertures have larger f-stop numbers and let in less light. Larger apertures have smaller f-stop numbers and let in more light.

The apertures (f-stops) go like so: F2.8 F4 F5.6 F8 F11 F16 F22 F32, and sliding along this scale (right to left) is called stepping up or stepping down. Each step results in a 50% light penetration difference.

Lenses

Two main types of lenses: Prime, and Zoom. Prime are locked to one view. Zoom allow you to…um…zoom. 3x means the object will become three times larger.

The next type of lenses are wide-angle vs. telephoto, which focus either on width or depth. These can be either prime or zoom. Something in between a wide-angle and telephoto lens is called a mid-range lens.

The next type of lenses are wide angle vs. telephoto, which focus either on width or depth. These can be either prime or zoom.

Aperture

Aperture is the opening in the lens that allows light in, and it can be made larger or smaller. A critical attribute of a lens is how large that opening can become, which is called an f-stop.

The f-stops are broken out like so: F2.8 F4 F5.6 F8 F11 F16 F22 F32. Sliding along this scale (right to left) is called stepping up or stepping down. Each step results in a 50% light penetration difference.

Smaller apertures result in larger depths of field. Closing the aperture by one f-stop gives you approximately 40% more depth of field.

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Aperture size affects blurring. Large apertures will heavily blur the background; smaller ones will only slightly do so.

Aperture affects lens performance–especially with non-prime (zoom) lenses. Lenses usually perform best when stopped down (smaller) by a few stops. A good rule of thumb is to shoot at F8 for maximum sharpness.

Depth of Field

In natural photography the depth of field is roughly 1/3 in front of the subject, and 2/3 behind it. When you’re extremely close up, however, it’s 1/2 in front and 1/2 behind.

Questions

Why does aperture affect clarity?

Sources

1 Much of this content came from this guide.

D7000

You can use the arrow keys to change the focus point during shooting, and the focus lock selector can keep that from happening.

Use the focus mode switch to switch from auto to manual to disable auto.