Monday, March 12, 2012


SCANNING

This weeks exercise was to scan 5 objects and 2 patterned fabrics. My scanner at home is a Cannon MP210, so the instructions on how to scan will be based on this type of scanner.

Firstly, you must consider what the end purpose of the image is going to be to determine what resolution (dpi) you should use.

  • Commercial printing = 300 dpi
  • Digital printing = 150-200 dpi
  • Web, email and multimedia = 72 - 96 dpi

How to scan:
  1. Open lid and place image face down, then close lid.
  2. Then on the side of the machine press the button that says "scan".
  3. A window should pop up called "image capture" on your computer screen
  4. Select the correct resolution, ensure it is scanning as an RGB, and select the correct filetype (jpeg). Ensure you have saved your image where you will be able to find it.
  5. Next press scan on the computer, and your document should save.


Exercise: Scan an image at different dpi, examine the difference between each image.

Scanned at 300 dpi


Scanned at 150 dpi

Scanned at 75 dpi
Its obvious that the image scanned at 300 dpi is clearer due to the increased amount of dots or pixels per inch, thus allowing the image not to be pixelated like the 75 dpi image.


Exercise: Scan 2 objects and 2 patterned fabrics.




Saving your image:

Its important to save your image correctly so that its can be used correctly, makes perfect sense right? well when scanning save your image as a jpg then you can bring it into photoshop and adjust it as need be.

However if like me you are saving your image to be used for a blog you must ensure you save your scan within photoshop as " save for web and devices".

To do this you simply click on file, then a drop down menu will pop up, next you click on "save for web and devices" and your set to upload your image on to the web. By saving your scan via save for "web and devices" your image will then be at 72 dpi resolution.

Image Modes

Last lesson we also learnt about image modes, Lea drilled into us that RGB is the most desired mode to work in, and should only be changed into another mode such as CYMK for printing purposes. Below are some examples of the modes!


RGB
  • Refers to Red, Green and Blue
  • primary image mode for graphics
CYMK
  • Mixture of colours to create images
  • Generally RGB images must be converted to CYMK for printing, However some of the brightness of RGB images are lost.


GRAYSCALE
  • Includes actual shades of grey
  • pixels are made up of white grey and black shades



DUOTONE
  • You can convert a grayscale image to a duotone image (2 colours)
  • easy way to add colour to a black and white image
BITMAP
  • Made up of pure black and white pixels with no shades of grey
Mccrossin. J. 2012, Moby, photograph, private collection.

Raster vs Vector

Last lesson we learnt about raster and vector images, along with the key differences of both. I also found a blog that illustrated what we had learnt, to visit this blog click here



Raster
  • Photoshop uses raster images
  • Resolution dependant
  • Uses DPI ( dots per inch) and PPI ( pixels per inch)
  • When scaled up the pixels get larger and the image becomes less clear
Amit Kr Sharma, 2011, "Vector graphics- vs- Raster graphics", Tutorials Twist, weblog, viewed 11th March 2012, http://tutorials-twist.blogspot.com.au/2011/07/vector-graphicsvsraster-graphics.html

Vector
  • Resolution independent
  • Illustrator uses vector images
  • Scaled down or up without distortion
  • Uses mathematical formula and no pixels