Photo Communications, Spring 2012 Columbia College Chicago

1. 22-3530 - 01 PHOTO COMMUNICATIONS
of pixels and bits

2. Measuring pixels

3. VECTOR IMAGES
Based on points & paths, numerical
Resolution independent

4. RASTER IMAGES (bitmap)
A mosaic of pixels (picture elements)
Resolution dependent

5. 1132 pixels
1430 pixels
Raster = Resolution Dependent
Each raster image is made of a speci c number of pixels
(pixel dimensions)

6. IMAGE DETAIL
Every time you capture a digital image, you create a speci c
number of pixels. Image detail is translated into differences
between pixels that the camera registers at the time of
capture. Increasing resolution degrades the true detail from
the capture with a ‘best guess’ (interpolation).

7. VIEW PERCENTAGE
1430 x 1132 1024 x 768

8. View percentage at 100%

9. View percentage at 60%

10. BIT DEPTH
Every raster image contains a certain number of pixels.
Every pixel contains a certain number of bits (ones or zeroes).
The number of bits contained in each pixel is called the
image’s bit depth.
for example,
If you are working with an 8-bit grayscale image,
each pixel contains 8 zeroes or ones.
2 = 01010101 = 256
8

11. 8 BIT vs (12 vs) 16 BIT

12. BIT DEPTH AND FILE SIZE
File size is directly connected to the number of bits
contained in an image. For example,
8 bits = a byte
If an 8-bit grayscale image has a pixel dimension of:
1430 x 1132 = 1618760 pixels
1618760 divided by 1024 (a kilobyte) = 1580.82
1580 divided by 1024 (a megabyte) = 1.54
1 kilobyte = 1024 bytes
1 megabyte = 1024 kilobytes

13. IMAGE SIZE WINDOW
Three different ways of describing
image size:
1. Image size
2. Pixel dimensions (count)
3. Document size: how the pixels
are distributed in the “real
world,” i.e., your printer

14. Tone

15. LEVELS
Hi-contrast Lo-contrast

16. HISTOGRAMS EVERYWHERE

17. TONAL KEY
Tonal character can be de ned in terms of light, dark, or
average, or use the terms high, low, and medium key.
high key medium key low key

23. DESTRUCTIVE EDITS
All tonal edits “damage” the le to some extent. Extreme edits to
tone using levels or curves can leave large tonal ranges completely
empty. These gaps in the histogram create what is called banding or
posterization.

25. NON-DESTRUCTIVE EDITS
Using adjustment layers
allows you to make tonal
adjustments without
permanently deleting
capture data.

26. SHADOW AND HIGHLIGHT
Be sure to always keep an eye on maintaining shadow and
highlight detail when making tonal edits.

27. for lm: Expose for the shadows and develop for highlights
for digital: Expose for highlights (most of the time)

28. BLOWN OUT
HIGHLIGHTS

29. PLUGGED
SHADOWS

30. CURVES
Curves allows you to focus your corrections more
accurately within the histogram than Levels.

31. BRIGHTNESS/CONTRAST ADJUSTMENTS

32. SHADOW
& HIGHLIGHT TOOL

35. Pixel quality control

41. SHOOTING ASSIGNMENT #2
Finding design patterns

42. Line
Shape
Texture
Space
Size
Value

43. LINE
Lines can organize, direct,
separate, be expressive,
suggest emotion, or create
rhythm. They can join
elements or divide them
using a rule, which is a line
that separates one element
in a design from another.

44. SHAPE
The external outline of a
form or anything that has
height and width.
An example would be the
three basic shapes: the
circle, the square, and the
triangle, considered to be
the fundamental shapes
found in all design.

45. TEXTURE
The look and feel of a surface. In two-dimensional form, texture is
essentially visual and adds richness and dimension to work. Texture can
also refer to pattern, which is visual texture.

46. SPACE
Refers to the distance
between shapes and forms,
but it is best understood
in design as white space or
negative space—terms
used to refer to the empty
but often active areas that
are void of visual elements.

47. SIZE
How big or small something is in
scale to other objects. Scale refers
to the process of making size
relationships. unless there is a
scale of reference within a design,
it is impossible to discern the
relative scale of objects and the
meaning they represent.

48. VALUE (& COLOR)
The relative lightness or
darkness of an area or object.
Value adds dimension by
creating the illusion of depth
in a design. With the addition
of a color, you can create and
convey a mood to enhance a
strong concept.