1. Monitor Sizes
Monitor sizes in the US are measured in inches, diagonal distance.
20” (inches)

2. Aspect Ratio 16 16 10 12 4:3 is most common  16:12
16:10 is common for wide screens 16 16 10
20” (inches) 12
18.87” (inches)

3. Aspect Ratio 16 15 10 12 5:4 is common for LCD’s (non-widescreen)
19” (inches) 12
18.87” (inches)

4. PPI / DPI 15” 12” Displays: Pixels Per Inch Printers: Dots Per Inch
60, 72, 96 are common
Printers: Dots Per Inch
300, 600, 1200 are common
96X15 = 1440px wide
96X12 = 1152px high
1440px wide
15”
19” (inches)
12”

5. Over-Sampling 15” 12” 7 Megapixel photo
2880×2304 5:4 6,635,520 pixels.
32-bit color  2^32 = 4 billion different colors
4 bytes per pixel
Grand total 24+ Megabyte file without compression.
What happens when you display this image full-screen on this monitor?
1440px wide
15”
19” (inches)
12”

6. Over-Sampling
Original Picture
What you really see on a 19” monitor.

7. Printing 11” X 8.5” 600 DPI printing How much resolution?
600 X 11 = 66,000 dot or pixels across
11” X 8.5”

8. Under-sampling Original Picture What you see on printed photograph
Original picture could have been sampled at a higher rate and the printed version would look better.

9. Printing Issues?
Is over sampling ever an issue when your output is a printed photo?
Even though most digital photos (10 Megabits or smaller) are under-sampled, why doesn’t it matter?

10. Crux of over-sampling? Device perspective:
What the device can produce in terms of resolution.
600 DPI is necessary for printing fonts,
Why?
Human perspective:
What the human can perceive with the naked eye.
600 DPI is overkill for printing photographs.
Why?

11. Resolution Depends on Content
Fonts are in fact vector-based, limitless resolution.
Fonts have smooth curves
Human eye can see jaggies in fonts are 120 DPI.
Photographs have blended colors and gradients.
Unless there are miniscule details, Human eye can not see jaggies in photos that are 120 DPI.

12. Practical Advice
Modern digital photography (10 Megapixels) is way ahead of display resolution.
However, modern digital photography is still behind of print resolution.
Unless you are going to print, 5+Mp is enough.
Example: 8 X 10 vs 16 X 20.