ACM202 Advanced digital technology
Week 1 – Wednesday, July 17th
- Move from print image to digital – data, photos rarely printed on paper.
This unit goes beyond analogue
- some history
- more sophisticated printing, camera, sensors, the digital work flow –
- ethical and social and political photographic contexts.
- Class attendance is vital.
- Familiarity with Unit Guide also vital.
- Assignments – read the design brief – follow precisely – including titles for files
- Assignment Work will be presented to class – and represents 10% – of each assignment –
Classes are a lecture and a 2 hour tute.
Brief outline of assignments –
About face – digitally retouching portraits. (see Photoshop disasters)
Online Identity – photography as internet art.
Unit blog – is a WordPress blog – a private blog – one has to log in
Students need to request permission to see the blog – highly recommended viewing. Acm202.wordpress.com
Asks for a user name and a password – one assignment in the course requires this anyway – we will build our own wordpress site.
Photoshop CS6 for photographers – book – large
ACM202 – What is digital photography?
The dematerialization of the photograph – image is now ‘dynamically mobile’ – never really finished
What is a digital image? – a pixel grid (usually square pixels) – e.g. Mario – 1980s – images had to be made with a few pixels –
The more pixels – the more approximation to continuous tone –
Pixels come from primitive art mosaics
Pixels are made of 1s and 0s. e.g. on or off switch – for pure b&w – 1_black, 0=white.
1s and 0s are bits – bit short for binary unit
Bit depth refers to how much tonal range is available for each pixel.
1-bit – just black or white
8 bit colour – RGB
The aim of digital technology is to create the illusion of continuous tone (posterisation occurs when there is less than this and the gradations are visible). (NB posterisation isn’t always bad – may be wanted)
Same with tone – the more levels of tone the closer to continuous tone to our eyes.
For an illusion of tone we need at least 200 levels of tone (usually 255 is used)
The world is continuous – how is it translated into a SLR camera to a digital image?
Censors are of 2 types – cmos (processing happens within the sensor), CCD (bayer array) – processing happens post sensor – CCD was developed by William S Boyle and George E. Smith and resulted in a Nobel Prize.
Sensor is a Bayer array (RGB) double the green sensors than blue or red – collect light photons – (NB light behaves dually = both as a particle and a ray) –
Film clip – How a pixel gets its colour (youtube) – complete black or white are either full pixels (white) or empty pixels (black)
The human eye is more sensitive to mid-tones than very dark or very light tones
One type of cells (cones – less numerous) is colour receptors, the other (rods – more numerous, more sensitive) records tonal information only –
Colour sensitive cones are clustered around the retina centre – the outer vision is actually shades of grey. (The fovea centralis is a 0.3cm diameter area which is rod free and contains very densely packed cones.)
Focus similarly – only 2 degrees right in the middle is in focus – the eye’s constant scanning gives the impression of a wider focus.
Nb mantis shrimp as much more colour band width than humans
Colour is a process in the brain where light of specific wavelengths is focused.
The human eye has fewer blue receptors – and they are further from the focal point –
Additive colour – rGB = produces white light – all 3 are needed to produce white light
By themselves the RGB channels are greyscale. All 3 are needed to show colour.
Artist – a pixel self portrait – Seth Lambert
Prac exercise 1 –
My artist name is Kelcany
Title – First shoe to drop
The final exercise was completed at home using different generated random artist name/album title/images.
Histogram of tonal scale described – clipped highlights and shadows –
To add a photograph from one PS file to another – select arrow, pick up picture – drop in the other file’s tab at the top.
Post this to the ACM202 blog – mandatory – see cloud page for video tutorials.
Unit Journal – this is an assignment –
– online notebook – of notes etc.
– establish a unit journal – this will be marked – wordpress (or other blogging software) – wordpress is big, easy to navigate, lots of support available.
Next task today – establish the site for your unit journal blog