1. Understanding Resolution & Digital Cameras
Ann Ware
Bald Knob High School
DC II Unit 2 Photography - Resolution and Digital Cameras_Use with Workshet

2. Resolution
Understanding digital cameras requires that we know how resolution works.
Resolution is determined by how many pixels (picture elements) or dpi (dots per inch) are available.
The image you see is simply a grid of small squares or circles filled in with color. The more squares or circles—the sharper the image.
The arrow is a link to the last slide, which is a picture of a lily. A portion of the center of the lily is enlarged in the top right corner to show the pixels.
DC II Unit 2 Photography - Resolution and Digital Cameras_Use with Workshet

3. Measuring Resolution
Resolution is measured by the number of horizontal pixels times the number of vertical pixels
Example: x 2304

4. Megapixels
The quality of a picture is measured by its resolution—how many pixels it has; the current measurement is megapixels
A megapixel is a grid containing one million pixels (one million squares of color)—technically, that is an image with a resolution of 1024x1024 pixels

5. Resolution
With computer graphics, there are three different resolutions to consider:
the image’s resolution (pixels)
the monitor’s resolution (pixels)
the printer’s resolution (dpi)
Question: What happens if the image resolution is higher than the monitor resolution?
Answer: You will not be able to view the image at its best quality
Question: What if the printer resolution is lower than the image resolution?
Answer: Your printed image won’t be the optimum quality. To get the optimum quality you will have to have it printed professionally.
DC II Unit 2 Photography - Resolution and Digital Cameras_Use with Workshet

6. Image Resolution The image’s resolution is measured in pixels.
Most cameras allow you to change the resolution before you take the picture.
The higher the resolution— the clearer the image— the bigger the file size.

7. Monitor Resolution
Monitor resolution is measured in horizontal and vertical pixels
Example: 1024x768
If an image is taken at 1280x960, but your monitor can only display 1024x768— that’s as good as it gets!

8. Printer Resolution
Printer resolution is measured in dpi—dots per inch The quality of the printed image is going to be determined by both the resolution of the image AND the resolution of the printer.

9. Point and Shoot Cameras
Most digital cameras designed for the consumer (vs. professional) are point and shoot cameras
They fall into three categories: subcompact, compact and super zoom
The camera lenses are built-in (not removable)
Basic features typically include auto focus, auto exposure and built-in flash
Not appropriate for action photography because of lag time
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10. SLR Cameras (Single Lens Reflex)
With an SLR camera, you see exactly what the lens sees
You can change the lens on a digital SLR
You choose the lens based on the type of photography; example: portrait photography vs. sporting events vs. landscape photography, etc.
SLRs produce higher-quality photos than point and shoot cameras
An SLR has a near-zero lag time, and is ideal for action photography
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11. Other points to consider
When purchasing a camera, you should also research the following specifications:
Storage Capacity
Transferring Images
Power Source
LCD vs. Optical View Finder
Zoom
Image Stabilization
The Exposure Triangle (Aperture, ISO, Shutter Speed)
DC II Unit 2 Photography - Resolution and Digital Cameras_Use with Workshet

12. Storage Devices Memory Card Internal Memory (RAM)
The number of pictures you can take before sending them to your computer is determined by two things:
The resolution of the image
The type of storage
                                

13. Transferring Images
Card reader
USB cable
Bluetooth

14. Power Source Regular Batteries Rechargeable batteries AC Alkaline
Nickel-metal hydride (NiMH)
Lithium-ion (Li-Ion) AC

15. LCDs vs ViewFinder LCD—Pro’s View Finder—Pro’s LCD—Con’s
Shows you the exact image that will be recorded
Easy to view … delete images, etc.
Displays menu
LCD—Con’s
Drains battery—uses ½ life of battery
Difficult to see in bright light
View Finder—Pro’s
Uses less battery
Easier to see images in bright light
View Finder—Con’s
Shows close approximation of the final image—not the real thing
Difficult for some people to see

16. Zoom Optical zoom actually enlarges the image—measured in X
example: 8X—increases an image 8 times
Digital zoom takes a portion of an image an enlarges it electronically; the image loses resolution when the camera enlarges it; also measured in X
Macro zoom allows you to take close-up pictures of objects that are small and enlarge them so they appear larger.

17. Image Stabilization
A feature in digital cameras that reduces the vibrations that can occur when taking a picture.
Vibrations commonly occur when shooting at slow shutter speeds, with longer lenses or with digital zoom.
Also called anti-shake

18. The Exposure Triangle
Exposure is the total amount of light you let into your camera. 
Too much light results in an over-exposed image where there are areas of bright white or ’blow-outs’.  These areas contain no detail or color. 
Too little light and an under-exposed image leaves parts of your image too dark to make out details.
The three components to exposure are ISO, shutter speed and aperture
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19. The Exposure Triangle
ISO—the measurement of how sensitive the image sensor in the camera is to light.
Measured in numbers 100, 200, 400, 800, etc.
Use a lower number when smooth crisp images are need and you have plenty of light.
Higher numbers are used when light is limited, you do not want to use a flash, or the subject is moving; may result in grainy images

20. The Exposure Triangle
Shutter Speed—the amount of time the shutter is open—which determines how much light is captured in the recording process
Measured in seconds: super fast 1/2000 second to 30 seconds
The slower the speed, the longer light can enter the camera. Appropriate for shooting pictures in darker situations; also great for freezing action and movement

21. The Exposure Triangle
Aperture—the camera feature that regulates the amount of light that passes through the lens by controlling the size of the opening in the lens
Described as the f/stop (a stop is a change in setting)
The smaller the number the wider the lens will open