Digital Camera Basics Amy Rudersdorf, NC State University Libraries Emily Gore, NC ECHO

Digital Camera Basics First half: mechanics of camera Printed materials offer a basic guide Second half: capture and lighting Learning curve with digital camera “ Craft of lighting” can take a lifetime to master

First half: mechanics of camera

Printed materials offer a basic guide

Second half: capture and lighting

Learning curve with digital camera

“ Craft of lighting” can take a lifetime to master

Digital Camera Basics: Mechanics Digital camera definition A (primarily) still camera that captures images as discrete numbers (as opposed to variable intensities of light) by an array of charge-coupled devices (CCDs) There is a fixed maximum resolution and number of colors that can be represented

Digital camera definition

A (primarily) still camera that captures images as discrete numbers (as opposed to variable intensities of light) by an array of charge-coupled devices (CCDs)

There is a fixed maximum resolution and number of colors that can be represented

Digital Camera Basics: Mechanics Analog photography Negative or slide film is medium of capture Digital photography The “film” is a light sensor* *Either a CCD (charge-coupled device) or CMOS (complementary metal oxide semiconductor)

Analog photography

Negative or slide film is medium of capture

Digital photography

The “film” is a light sensor*

*Either a CCD (charge-coupled device) or CMOS (complementary metal oxide semiconductor)

Digital Camera Basics: Mechanics Light sensors Convert light into thousands [or millions] of pixels Pixels are tiny “dots” in which color/light data is stored Capture occurs at single moment when shutter opens and closes

Light sensors

Convert light into thousands [or millions] of pixels

Pixels are tiny “dots” in which color/light data is stored

Capture occurs at single moment when shutter opens and closes

Digital Camera Basics: Mechanics Digital camera types Point & shoot (P&S) Single lens reflex (SLR) Overhead/stationary “Scan backs”

Digital camera types

Point & shoot (P&S)

Single lens reflex (SLR)

Overhead/stationary

“Scan backs”

Point & Shoot (P&S): Digital Cameras Adjusts settings such as focus and exposure automatically Some P&Ss offer manual controls Compact Typically has LCD* screen; may have viewfinder LCD screen is excellent because it reduces image to two-dimensional view *Liquid crystal display

Adjusts settings such as focus and exposure automatically

Some P&Ss offer manual controls

Compact

Typically has LCD* screen; may have viewfinder

LCD screen is excellent because it reduces image to two-dimensional view

Single-lens reflex (SLR): Digital Cameras “Professional-level” cameras View image through viewfinder Much better for action, but limits the user to viewing through camera Interchangeable lenses, higher quality optics Larger than P&Ss High ISO (light sensitivity) Shutter response is faster than P&Ss

“Professional-level” cameras

View image through viewfinder

Much better for action, but limits the user to viewing through camera

Interchangeable lenses, higher quality optics

Larger than P&Ss

High ISO (light sensitivity)

Shutter response is faster than P&Ss

Single-lens reflex (SLR): Digital Cameras Mirror behind the lens reflects light coming into camera onto a ground glass screen View through lens is seen through viewfinder As shutter button is pressed, mirror lifts away to allow the light to reach image sensor and board where image is captured

Mirror behind the lens reflects light coming into camera onto a ground glass screen

View through lens is seen through viewfinder

As shutter button is pressed, mirror lifts away to allow the light to reach image sensor and board where image is captured

Single-lens reflex (SLR): Digital Cameras

Overhead/Stationary: Digital Cameras High-volume reproduction High-quality reproduction Single angle of view Expensive Programmatic Mostly used for two dimensional art and books

High-volume reproduction

High-quality reproduction

Single angle of view

Expensive

Programmatic

Mostly used for two dimensional art and books

“ Scan-back” : Digital Cameras Scanning sensor usually replaces film in large-format view camera Scanning backs use a CCD sensor with a single row of pixels (sensing elements) that physically moves (scanned) across the image area, capturing one row of information at a time Extremely high resolution and quality Long capture time Requires high-end optics, dedicated computer $20,000+

Scanning sensor usually replaces film in large-format view camera

Scanning backs use a CCD sensor with a single row of pixels (sensing elements) that physically moves (scanned) across the image area, capturing one row of information at a time

Extremely high resolution and quality

Long capture time

Requires high-end optics, dedicated computer

$20,000+

Choosing a Digital Camera Most camera packages are not designed (primarily) for photographing objects Standard lenses for “landscape” or people May need to purchase a special lens, e.g., macro, to capture object detail Manual exposure controls are essential Automatic exposure will make white or black background grey

Most camera packages are not designed (primarily) for photographing objects

Standard lenses for “landscape” or people

May need to purchase a special lens, e.g., macro, to capture object detail

Manual exposure controls are essential

Automatic exposure will make white or black background grey

Choosing a Digital Camera Best if the camera can be “tethered” to a computer to allow live viewing of subject Resolution is important, but only if the lens is of adequate quality and the camera is reasonably easy to use Any digital SLR camera will meet requirements, a carefully chosen high-end P&S may suffice

Best if the camera can be “tethered” to a computer to allow live viewing of subject

Resolution is important, but only if the lens is of adequate quality and the camera is reasonably easy to use

Any digital SLR camera will meet requirements, a carefully chosen high-end P&S may suffice

Digital Camera Basics: Resolution DPI – dots per inch The measurement of resolution of display, printing, and capture systems. As the “dot” (or pixel) rate doubles, the number of dots quadruples. 100 dpi = 100 x 100 = 10,000 dots/pixels per inch 200 dpi = 200 x 200 = 40,000 dots/pixels per inch http://photo.net/equipment/digital/basics/index?&for_print=1

DPI – dots per inch

The measurement of resolution of display, printing, and capture systems. As the “dot” (or pixel) rate doubles, the number of dots quadruples.

100 dpi = 100 x 100 = 10,000 dots/pixels per inch

200 dpi = 200 x 200 = 40,000 dots/pixels per inch

Digital Camera Basics: Resolution A 5 x 7 inch photograph captured at 600 DPI will be how many pixels across on its longest edge?

A 5 x 7 inch photograph captured at 600 DPI will be how many pixels across on its longest edge?

Digital Camera Basics: Resolution ANSWER: 7 inches x 600 = 4200 dpi on the longest edge 8 x 10 inches at 300 dpi is the same as: 4 x 5 inches at 600 dpi 32 x 40 inches at 75 dpi

ANSWER:

7 inches x 600 = 4200 dpi on the longest edge

8 x 10 inches at 300 dpi is the same as:

4 x 5 inches at 600 dpi

32 x 40 inches at 75 dpi

Digital Camera Basics: Resolution Different output devices require different resolution Computer screens display at 72 dpi, although software may zoom in Print devices print no higher than 300 dpi Human eye cannot discern more than 300 dpi without magnifier For digital preservation higher resolution is better What sort of detail will a researcher need? What will future technologies be able to display?

Different output devices require different resolution

Computer screens display at 72 dpi, although software may zoom in

Print devices print no higher than 300 dpi

Human eye cannot discern more than 300 dpi without magnifier

For digital preservation higher resolution is better

What sort of detail will a researcher need?

What will future technologies be able to display?

Digital Camera Basics: Resolution Confusing terminology! Many printers offer high dpi, e.g., 1440 dpi Refers to the microscopic pixels that make up the printing dots that are at 300 dpi or less A printer with higher dpi offers more gradations of color , rather than higher resolution.

Confusing terminology!

Many printers offer high dpi, e.g., 1440 dpi

Refers to the microscopic pixels that make up the printing dots that are at 300 dpi or less

A printer with higher dpi offers more gradations of color , rather than higher resolution.

Digital Camera Basics: Resolution and Megapixels Megapixels The n umber of pixels that comprise the surface of the image sensor 1 megapixel = 1 million pixels A 4.0 megapixel (or higher) can output an acceptable 8 x 10 inch printed image 4 MP cameras have 2,289 x 1,712 pixels 200 DPI image is 11.4” x 8.6” 14 MP cameras have 4,500 x 3112 pixels .

Megapixels

The n umber of pixels that comprise the surface of the image sensor

1 megapixel = 1 million pixels

A 4.0 megapixel (or higher) can output an acceptable 8 x 10 inch printed image

4 MP cameras have 2,289 x 1,712 pixels

200 DPI image is 11.4” x 8.6”

14 MP cameras have 4,500 x 3112 pixels .

Digital Camera Basics: Resolution and Megapixels Megapixels do not equal quality! Camera manufacturers have greatly increased megapixel resolution, but noise has increased as well Physically larger sensors have less noise Digital SLR cameras offer noticeably better images compared to P&S cameras with higher numbers of pixels because P&Ss tend to be physically smaller cameras http://photo.net/equipment/digital/basics/index?&for_print=1

Megapixels do not equal quality!

Camera manufacturers have greatly increased megapixel resolution, but noise has increased as well

Physically larger sensors have less noise

Digital SLR cameras offer noticeably better images compared to P&S cameras with higher numbers of pixels because P&Ss tend to be physically smaller cameras

Digital Camera Basics: File Formats Digital images can be encoded in many ways Most digital cameras record JPEG by default Lossy compression RAW format recorded from the sensor offers the most color and brightness detail However, each camera manufacturer has a different standard Some cameras can record TIFF files, which is the archival standard Recommended

Digital images can be encoded in many ways

Most digital cameras record JPEG by default

Lossy compression

RAW format recorded from the sensor offers the most color and brightness detail

However, each camera manufacturer has a different standard

Some cameras can record TIFF files, which is the archival standard

Recommended

Digital Camera Basics: Capture Basic photography concepts Aperture Shutter speed White balance Lighting conditions (Exposure) Bracketing Other considerations Background 2d objects 3d objects

Basic photography concepts

Aperture

Shutter speed

White balance

Lighting conditions (Exposure)

Bracketing

Other considerations

Background

2d objects

3d objects

Digital Camera Basics: Capture Aperture The size to which the shutter opens to let light in to the sensors The smaller the f-stop number, the larger the opening The larger the f-stop number the greater the depth of field, or perception of distance Similar to squinting http://electronics.howstuffworks.com/how-to-digital-camera.htm

Aperture The size to which the shutter opens to let light in to the sensors

The smaller the f-stop number, the larger the opening

The larger the f-stop number the greater the depth of field, or perception of distance

Similar to squinting

Digital Camera Basics: Capture Aperture (slide 2) f/32 f/# 0.5 0.7 1.0 1.4 2 2.8 4 5.6 8 11 16 22 32 45 64 90 128 f/5 For f/32 or smaller (number wise) or larger (apeture wise) -- you’ll need a tripod because the lens will be open for a good long time.

Aperture (slide 2)

Digital Camera Basics: Capture Shutter speed The amount of time the shutter is open, allowing light to be exposed to the sensors A fast shutter speed “freezes” movement A slow shutter speed shows, or “blurs” movement Measured in (parts of) seconds, e.g., 1/500 Indoor settings: somewhere around 1/100 or 1/200 (you’ll need a tripod for anything slower than 1/60 or so) http://electronics.howstuffworks.com/how-to-digital-camera.htm

Shutter speed The amount of time the shutter is open, allowing light to be exposed to the sensors

A fast shutter speed “freezes” movement

A slow shutter speed shows, or “blurs” movement

Measured in (parts of) seconds, e.g., 1/500

Indoor settings: somewhere around

1/100 or 1/200 (you’ll need a tripod for

anything slower than 1/60 or so)

Digital Camera Basics: Capture White balance In a camera, a setting that compensates for the differences in color temperature of the surrounding light. White balance adjusts the image’s colors to look similar to daylight You can set custom white balance using a “white card”

White balance In a camera, a setting that compensates for the differences in color temperature of the surrounding light.

White balance adjusts the image’s colors to look similar to daylight

You can set custom white balance using a “white card”

Digital Camera Basics: Capture White balance (continued) Indoor lighting is very different from natural lighting Incandescent lights (light bulbs) are yellow-red compared to sunlight Fluorescents tend to look green P&S will try to make the background and the subject an even grey color http://www.scrapjazz.com/topics/Photography/Lessons/587.php

White balance (continued) Indoor lighting is very different from natural lighting

Incandescent lights (light bulbs) are yellow-red compared to sunlight

Fluorescents tend to look green

P&S will try to make the background and the subject an even grey color

Digital Camera Basics: Capture Lighting conditions Aperture and Shutter Speed are determined by the availability and source of lighting Bright, sunny or hazy light allows for smaller apertures and faster shutter speeds: f/16, 1/500 Overcast, close-up, back-lit subjects: f/5.6, 1/500

Lighting conditions Aperture and Shutter Speed are determined by the availability and source of lighting

Bright, sunny or hazy light allows for smaller apertures and faster shutter speeds: f/16, 1/500

Overcast, close-up, back-lit subjects: f/5.6, 1/500

Digital Camera Basics: Capture Exposure The amount of light falling on the sensor Proper exposure is critical for image quality Determined by: Brightness of the scene Quality of the sensor Shutter speed (ISO) Aperture

Exposure The amount of light falling on the sensor

Proper exposure is critical for image quality

Determined by:

Brightness of the scene

Quality of the sensor

Shutter speed (ISO)

Aperture

Digital Camera Basics: Capture Bracketing Taking several shots of the same subject using different or the same camera settings Typically used when lighting is challenging or there is lots of movement 125th/sec @ F8 – correct exposure 60th/sec @ F8 – overexposed 1 stop 250th/se @F8 – underexposed 1 stop

Bracketing

Taking several shots of the same subject using different or the same camera settings

Typically used when lighting is challenging or there is lots of movement

Digital Camera Basics: Capture Backgrounds Plain, non-reflective surface keeps focus on subject Try several different colors or textures Neutral colors typically work best Smooth out unnecessary folds Cloth, table surface, foam core, etc.

Backgrounds

Plain, non-reflective surface keeps focus on subject

Try several different colors or textures

Neutral colors typically work best

Smooth out unnecessary folds

Cloth, table surface, foam core, etc.

Digital Camera Basics: Capture Papers, maps, and photos (“flat” material) Soft, even light across entire surface. No glares or light spots Two-dimensional objects http://uwdc.library.wisc.edu http://www.dkimages.com/discover/previews/805/450713.JPG

Papers, maps, and photos (“flat” material)

Soft, even light across entire surface. No glares or light spots

Two-dimensional objects

Digital Camera Basics: Capture Avoid keystoning, or distortion: photograph from a central point directly above (if laid horizontally) or parallel (if vertically) Resolution: sufficient that the digital surrogate can be reproduced at the same or larger size as original Two-dimensional objects

Avoid keystoning, or distortion: photograph from a central point directly above (if laid horizontally) or parallel (if vertically)

Resolution: sufficient that the digital surrogate can be reproduced at the same or larger size as original

Two-dimensional objects

Digital Camera Basics: Capture Three-dimensional objects Household items, sculpture, clothing, tools Avoid light spots or extreme shadows Get close Consider taking more than one photograph (e.g., full & detail) Shoot in the shade or on a cloudy day to take advantage of soft lighting and to show more detail Expect to experiment, and that means time! http://digicoll.library.wisc.edu/Arts/

Three-dimensional objects

Household items, sculpture, clothing, tools

Avoid light spots or extreme shadows

Get close

Consider taking more than one photograph (e.g., full & detail)

Shoot in the shade or on a cloudy day to take advantage of soft lighting and to show more detail

Expect to experiment, and that means time!

Digital Camera Basics: Environment Camera. Check. What else do you need? Lights Physical space Accessories Ladder, table, tripod Gloves, object stands Computer storage – or direct computer connection Others?

Camera. Check. What else do you need?

Lights

Physical space

Accessories

Ladder, table, tripod

Gloves, object stands

Computer storage – or direct computer connection

Others?

Digital Camera Basics: Environment Physical space recommendations Dedicated Appropriate and adequate lighting Adequate physical space to capture your objects A large object will require a greater amount of space for capture Quiet and clean Ideally, the walls and floors are neutral colors and low reflection Storage for accessories when not in use

Physical space recommendations

Dedicated

Appropriate and adequate lighting

Adequate physical space to capture your objects

A large object will require a greater amount of space for capture

Quiet and clean

Ideally, the walls and floors are neutral colors and low reflection

Storage for accessories when not in use

Digital Camera Basics: Costs Digital Camera 10 Megapixel P&S => $300 10 Megapixel SLR => $900 Scan-back systems => $25,000+ Lenses $100+ Lights 2-light “economy” kits start at $150 Tripod $25-$300

Digital Camera

10 Megapixel P&S => $300

10 Megapixel SLR => $900

Scan-back systems => $25,000+

Lenses

$100+

Lights

2-light “economy” kits start at $150

Tripod

$25-$300

Digital Camera Basics: Costs The top-rated 8 MP (and up) semi-pro SLR cameras reviewed by CNET staff as of 10/8/2007 were Nikon’s D200 and Canon’s EOS 20D. They cost between $800 and $2000.

The top-rated 8 MP (and up) semi-pro SLR cameras reviewed by CNET staff as of 10/8/2007 were

Nikon’s D200 and

Canon’s EOS 20D.

They cost between $800 and $2000.