B.Sc. (Hons) Multimedia Computing

Media Technologies

Digital Photography

Agenda

Digital Principles Camera Types Lens Principles Common Features Legacy Issues

B.Sc. (Hons) Multimedia Computing

Media Technologies

Digital Camera Principles

Digital Principles

Filters

Light from scene

Sensor

Analogue Electrical Signal

Analogue to Digital Converter

Digital Signal

White balanceAnti-aliasingCompression

Buffer

Storage

Digital Principles

Size of sensor determines resolution of images

3008

2000

3008 x 2000 = 6,016,000 = 6 Megapixels (6MP)

Buffer size also important - buffer size determines many images you can take in quick succession

Types of Digital Camera

Types of Digital Camera

Compact rangefinder type cameras -Limited features - aimed at general users ( novice / occasional use)

Prosumers Types - aimed at the advanced amateur / semi pro user - more sophisticated functionality - probably has a wide ranging zoom lens - but not interchangeable - affordable price

DSLRs (Digital SLRs) full system cameras with interchangeable lenses and other professional accessories such as dedicated flash systems etc. Expensive as compared with prosumer models

Digital Camera Types

Compact

Prosumer

DSLR (Full Frame Sensor)

Lenses for Digital Cameras

Lenses for Digital Cameras

Question Are digital camera lenses the same as film camera lenses?

Answer Yes - but effect focal length depends on size of digital sensor used in

camera

Lens image circle coverageFull frame 35mm film gate

Lenses Circle Coverage

Sensor not full frame thus any lens will have telephoto effect as compared with equivalent filmcamera lens

Full Frame Sensor

Sensor full frame thus any lens coverage and focal length the same as for film camera lenses

Common Principles

Common Photographic Principles

Subject Matter ‘The Great Themes’ Portraiture Still Life Landscape Social and Documentary

Lighting and Exposure Available light (natural light) Flash Studio

Composition - ‘Rule of Thirds’ Gadgets (Lenses, Tripods, Filters, Bags)

Flash and LightingThree Important features of a flashgun

1. Guide Number - indicates light power available

e.g (30 Meters at 100 ISO) reasonable power for average use

2. Recycling time - how long (in seconds) flash takes to be ready for next

3. Thru-The Lens (TTL) flash metering

Guide number: 165 in feet / 50 in meters 105mm (ISO 100)Charge time: Approx. 6seconds (when using alkaline batteries) Approx 4seconds (when using NiMH batteries)

Pro Flash Lighting

Guide Number = 60 Metres at ISO 100

Pro Lighting -Studio Flash

Continuous background paper

Product Photography

Copy Stands - provide consistent diffuse lighting for photographing product items

Flash Photography Tips

Use the Flash off-camera Bounce lighting from white surface to diffuse lighting

Inverse Square Law - doubling the distance requires four times the light

What’s Changed ?

Changes in the Digital Era

Traditional Photography Take pictures then develop and print using chemical

processes in a ‘Darkroom’ - or send to a film lab Digital Photography

Take pictures then upload to a computer and edit in graphics application or dedicated software application usually bundled with camera - can take a long time!

What images to print - often get left on the computer Professional software available - Aperture and Lightroom Software ‘Media Centres’ replaces the old technology of a

slide projector and slide show Take memory card to digital photo booths etc

The Darkroom

Digital Image Processing in ‘The Light Room’

Image Formats and Software

Formats Uses established image formats such as JPEG and GIF New formats such as RAW - a raw i.e. ‘unprocessed’ image file contains

minimally processed data from the image sensor of a digital camera and must be processed to be used as an editable image such as JPEG or GIF. Contents of RAW files are often considered to be of 'higher quality' than the RGB converted results.

RAW files different for each manufacturer - Adobe has developed .DNG Digital NeGative as a de-facto standard for RAW data to encourage usage of a common RAW format to prevent future legacy issues.

Software Adobe recently released version one of Lightroom - an integrated

digital image editing and photographic library management system (PC & MAC)

Aperture - similar to Lightroom - aimed at professionals - already fairly well established in the professional market

B.Sc. (Hons) Multimedia Computing

Media Technologies

Legacy Issues

Digitizing Legacy Formats

Converting film to digital … Scan-in images and transparencies (slides) Scan negatives into a digital format

Nikon Coolscan 5000 ED (35mm)

Nikon Coolscan9000 ED35mm & 120 film (medium format)

Converting Film Cameras ?

35mm film cameras have a common filmchamber design…

Converting Film Cameras

Most 35mm film cameras have interchangeable backs e.g. data backs etc.

Converting Film Cameras

Solution - a digital sensor that fits inside the film chamberand captures images at the film plane

Silicon Film...

Digital sensor film insert fits most SLR cameras!

Silicon Film Cartridge

Sensor

Silicon Film...

Transfer images from cartridge via Photoshop Plug-in

Silicon Film: April 2001

Image imported into Photoshop

Silicon Film 2002 2003

New 10 MP sensor fits most cameras

To be shown at Photokina

Software References

B.Sc. (Hons) Multimedia Computing

Media Technologies

www.adobe.com - Lightroom tryout www.apple.com - Aperture tryout