Photoshop Workshop

In this workshop we will mainly be working with photo manipulation. It is the main editing program that manipulates photographs. Photoshop works with pixels, which is a square of colour. With pixels things can blur and distort (pixelation) things begin to appear 'blocky'. 

One thing different to vector graphics is that working with pixels we need to think a lot more about size and the quality of an image. Pixelation is a common problem unique to bitmap. Early graphical applications such as video games ran at very low resolutions with a small number of colours, and so had easily visible pixels. This then resulted in sharp edges that gave curved objects and diagonal lines an unnatural appearance.

Resolution is a word to describe the amount of pixels given and information about the image. The most standard resolution given is 72, which is the standard all digital display, as well as a resolution of 300 which is the standard used for print. This is because, it is of high quality that the eye can interpret easily (especially for magazines) however, for a massive bill board alongside the motorway you could probably get away with using a lower resolution and it will still look of high quality. 

Optical Colour Mixing is created through our perception of colour. When we look at two small amounts of different colours laid down side by side the two appear to create a different colour. This colour usually is something similar to the result when the two are mixed in pigment. The only difference is that when two colours are mixed in pigment, they lose some of their intensity. When two colours are mixed optically, they retain their intensity and sometimes appear a lot brighter.

 

When working in Photoshop the colour mode is pre-set to RGB (red green blue), deals with light and works digitally for the web. CMYK works for print and pigments of inks, when working in this colour mode in Photoshop, you would find not all the filters and options would not be available to use. CMYK refers to the four inks used in some colour printing: cyan, magenta, yellow, and key (black) To look for different colour modes and change them, you can find them on image-mode-colour mode. 

The RGB colour mode is an additive colour model in which red, green, and blue light are added together in various ways to reproduce a broad array of colours. The name of the model comes from the initials of the three additive primary colours, red, green, and blue.The main purpose of the RGB colour model is for the sensing, representation, and display of images in electronic systems, such as televisions and computers, though it has also been used in conventional photography. Before the electronic age, the RGB colour model already had a solid theory behind it, based in human perception of colours.

Gamut

With a colour gamut you can see the complete range and scope of colour. One thing, that is really noticeable is that you get a lot more of a wide range of colour when using RGB colour mode, especially a lot more greens. CMYK is a lot more restricted. For example...

CMYK

RGB

From the image examples above, one thing you can really notice, is that the green is a lot brighter when in RGB mode. 

Finally, Photoshop useful shortcuts: