Through the lens: bracketing

Showing posts with label bracketing. Show all posts

20 July 2011

Photography Basics

Susan Brannon

20 July 2011

How a Camera Works Made Simple

The word “photography” is French derived from the Greek language, in English it means “drawing from light”. Photography is really all about light and how the camera works.
In a camera, light travels from the object to the sensor in film cameras. The light goes through the lens to the sensor.

When you set your aperture inside the lens, that opens and closes depending on how you set it, little or lots of light will hit your sensor. The aperture is controlled by “f stops” f2.8 is wide and f/19 is small. The lower the number, the more light will be let in. (Remember this and it will be of great help!) Once the light hits your sensor, and is absorbed and transforms into pixels.

The image that the sensor picks up is upside down and then flips it.

The shutter is what controls how long the sensor is exposed, the longer the shutter is open the more light can be absorbed onto the sensor. There are numbers that represent the speed of the shutter, 1/1000 of a second is fast and 3 seconds is slow. Remember, the lower the number the less light will be let in. The amount of light absorbed by your sensor is called “exposure”. There are two things that control the exposure, the shutter speed and the aperture.

In addition, you have film that has sensitivity to light; in digitals, it is your sensor that is sensitive to light. The film speeds of the film (sensitivity) are called ISO. A low ISO speed required longer exposures; a high ISO speed requires less time to give the same exposure.

One might ask, “Why are there all these controls? Can’t we just use one control to tell the camera how much light to let it?” Well, The various controls allow you to control other aspects of an image. A shutter speed can help to freeze the subject in motion; the aperture controls the depth of field and what is focused in your image.
Complicated? All this means is that you must understand, how much light you need to expose to your film or sensor in order to generate the type of image that you desire.

*Tip: Remember:
Shutter Speed: The lower the number the less light
Aperture: The higher the number the less light
ISO: The higher the number the more sensitive the film or sensor is to light.

Documentary Photography Lesson 1

Documentary Photography Lesson 2

Street Photography Lesson 1

Street Photography and your Camera

Street Photography Tips

Holga Camera

F/16 Rule and Apertures

What is the difference between Street Photography and Documentary?
Four Easy Steps to Learn panning

Tips for Night Photography

Aperture and f/16 Rule
Shutter Speed Basics

Bracketing

Rule of Thirds

Depth of Field

Photography Basics

Common Photography Terms

Focused Bracketing or Photo Stacking
Exposure

14 July 2011

Focus Bracketing or Photo Stacking

Focus Bracketing: (or Stacking)
Susan Brannon

This is useful with limited depths of field mostly used in macro photography where you can focus the subject at different positions. Take several images of the same subject each with a different focus spot. For example, take an image of a flower and let your camera automatically bracket your image. You will notice that the image may be focused in the front (closest) to your camera, and blurred at the back. Now, take that same flower, and bracket focus on the back of the flower instead, manually. The front of the flower is blurred, while the back is in focus.

There is a term “focus stacking” that by taking a sequence of various parts of the subject in focus and combining them together to create the entire subject in focus. This is not easy to do, because it requires delicate use of PhotoShop to combine the images!

Some tips:
1) Focal length - The longer your lens, the more shallow your depth of field is.
2) Distance to the subject: The nearer you are to your subject, the shallower your depth of field is, especially with a macro lens.
3) Aperture settings: The more you open the aperture, the shallower your depth of field will be.

How do you do this?

A) Use a steady tripod.
B) A macro lens, to get really close.
C) Super precision: Lock your camera on your tripod, so you cannot move your camera.
And rely on your in camera focus points to focus on different parts of the image.
D) Patience: This process takes quite some time
E) Post processing software, that can handle focus stacking.
F) Create a file with layers, stacked on each in a linear arrangement. Do not jumble the sequence of focused images.
G) Align layers
H) Blend layers

Image below from Wikipedia:

Documentary Photography Lesson 1

Documentary Photography Lesson 2

Street Photography Lesson 1

Street Photography and your Camera

Street Photography Tips

Holga Camera

F/16 Rule and Apertures

What is the difference between Street Photography and Documentary?
Four Easy Steps to Learn panning

Tips for Night Photography

Aperture and f/16 Rule
Shutter Speed Basics

Bracketing

Rule of Thirds

Depth of Field

Photography Basics

Common Photography Terms

Focused Bracketing or Photo Stacking
Exposure

13 July 2011

Bracketing

Susan Brannon

Cameras do not see the world the way that we do, and sometimes we find that an image is too dark and you cannot distinguish any detail. The camera is based on the different hues of gray. You use bracketing when the lighting condition is difficult for your sensor to read, creating under or over exposures. For example, taking images in the snow, you camera will automatically make things darker. How do you resolve this problem? You must tell the camera what exposure you want to use.

Slide, film and digital work in different ways. Slide is very sensitive and where you would set your exposure for your digital, will not work for the slide; your image may not even show up! Film you only see the effect when it is pronounced.

The term bracketing usually refers to exposure bracketing: the photographer chooses to take one picture at a given exposure, one or two brighter, and one or two darker, in order to select the most satisfactory image. Many digital and film cameras, can automatically shoot a bracketed series of pictures.

Exposure bracketing is dealing with high-contrast subjects with a limited range or sensor.
Exposure bracketing is using your camera to create a high dynamic range that exposes the portions of the image by different amounts. (Also see exposure)

You can set your bracketing setting on your camera to different stops,-4 stops -2 stops, +2 stops etc…This is what allows different amount of light into your sensor and changes your exposure.

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