Photoshop Induction

Photoshop uses pixels to create a piece of work. These are essentially small squares of colour. If they are blown up too large then the image looks blurry  this is called pixilation  The resolution is how many pixels are in a given area. Different size resolutions are used for different things. For example 72 dpi for screens or online work, 300 is used for print. 

Even though the image is made up of squares they blend together and the quality of the photo blends well. You need a higher resolution because it is closer to your eyes so the dots are smaller so you see the whole image. On the other hand with a bill board or a poster that is hung down the side of the building can be a lot lower resolution because people have to stand further away to view the full image. 

Optical mixing is taking two colours and making a new colour. You couldn't mix two pigments together but by placing them very finely together your eyes begin to read them as one colour. It is quite like flicking yellow paint onto a piece of paper and then flicking red over the top. Although both colours remain separate then your eyes merge them together.



Theres a link between the amount of pixels and the size of the file. Maximum pixels you can have in one photoshop image is 300,000 x 300,000! 

If you are working on a web document then if you go higher than 72dpi then the images will take longer to load because the pixels will be too big for the screen. When you create a website you pay for pixel space used. 

Meta data is extra information which is hidden in the file. Depending on the camera it will tell you the settings. 

Image > Image Size. Resample Image off will just redistribute information it won't delete anything or add anything. If an image is 72 dpi but the width:height is 203.2:135.47  then to take it up to 300 for printing then the width and height would be pulled in as the pixels stay close together. Because your not deleting any pixels it will shrink the image size as they pull closer together. when the resolution is changed to 300 the size is altered to 48.77:32.51. 

On the bottom left the "Doc:" if right clicked on then the size and resolution appears.

Colour:

RGB (red green blue) used for screen, it deals with light

CMYK (cyan magenta yellow key) used for print 

even if your working to print you use RGB because some filters aren't available for CMYK because they are designed to work for RGB. In the final steps of creating work then  you save the RGB one as a working document, make a duplicate in CMYK to print.

Gamuts is the complete range of visible colour  

As you can see there is a difference in the colour range between RGB and CMYK.
What you can reproduce with CMYK is a lot less than RGB.

The colour box with with exclamation mark in a triangle is showing that this colour could not be printed exactly as it is out of the gamut range. However if you right click on it it moves the circle to a colour which is similar and able to print. The small cube underneath means it is a web safe colour, a similar thing to before where if you click on it it will move it to the closest  web safe colour.

Hex code is shown at the bottom and highlighted. This is for web safe colours so that they can be used online.  The number correlates online or can be put into other software to get exactly the same colour.