JRN 440 Adv. Online Journalism Adjustments, Image Mode

1. JRN 440Adv. Online JournalismAdjustments, Image Mode Wednesday, 2/1/12

2. Class Objectives • Lecture • Adjustments (brightness/contrast, levels) • Image Mode • Homework • P1 due Wednesday, 2/15, at 2:05 p.m.

3. Tonal Adjustments • Need to stretch and squeeze the bits • Every time you make a correction, you loose data/bits • The more data you have at the beginning, the better • Making multiple tonal corrections is worse than making 1 correction (increasing rate of data lost) • Remember to always keep a copy of your original image (file and layer)

4. Tonal Adjustments: Brightness and Contrast • <Image <Adjustments <Brightness/Contrast • Least amount of control for tonal correction • Brightness shifts all values up or down (you lose your blacks) • Contrast throws away information from both highlights and shadows • Final thoughts on – NEVER USE!

5. Tonal Adjustment- Levels • Histogram • Destructive is <Image < Adjustments < Levels • Non-destructive is to click on your layer image, and select “Create new fill or adjustment layer” With adjustment layers, you can also add a mask Eye droppers work to set (or clip) highlights, midtones, and shadows Right slider controls highlights Middle slider adjusts midtone values Left slider controls shadows and blacks

6. Histograms • What do they tell you? • If a photograph has been manipulated • Look for combs • If you have missing channels of information due to manipulation • What can you do with them? • Change the mid tones of an image w/o losing the white and black details

7. Tonal Adjustment What is posterization? What does it tell you? That an image has been manipulated too much (stair stepping affect instead of continuous transition) Is posterization good or bad? • Intentional • < Image <Adjustments <Posterize • Non-intentional- can see on levels

8. Image Mode • Your image mode determines limitations of Photoshop features • Why can’t you do some filters in CMYK? • May have to step-by-step change image modes to get to desired mode • IE- have to change RGB to GrayScale to get to Bitmap • Every time you change image modes, you throw away information • Suggested use for designing for print- try to do as much as possible in RGB before converting to CMYK

9. Image Mode • What is it? • A way of organizing the bits (composed of 0’s and 1’s) to describe a color • Why was it created? • So that the color is same on every computer • Most important color modes (to a designer) represented in Photoshop

10. RGB • Set this image mode either at <File <New or <Image <Mode • Red, Green, Blue • Color mixture in light • Additive: all added together make white

11. RGB • Screen dependent • Used for web images (monitors), cell phone screens, laptop images… anything that is “back lit” • 16.7 million colors • Because of this wide range in colors, Photoshop lets you do everything while in this color mode • Most commonly seen in filters

12. CMYK • Set this image mode either at <File <New or <Image <Mode • Cyan, magenta, yellow, and black(k) • Color mixture in print • Subtractive: all added together make black Due to impurities of ink, all added together really makes it muddy brown, so we add black ink

13. When to use CMYK • If you are working as a graphic designer and will be sending your image to a conventional printer, you will need to convert to CMYK • If not, they will charge you an extra fee to do this

14. When to use RGB • If you are printing to a laser, inkjet, or dye sub printer • If you are sending your image to an on-line printing site (MPix) • Although the inks are CMYK, the printer software will use a RGB profile and convert to CMYK automatically. So stay in RGB.

15. CMYK • CMYK has a smaller number range of color than RGB, therefore you will be unable to do everything in Photoshop when in this mode • Best advice, always start in RGB and make your all of your changes, then, as a last step, convert to CMYK image mode.

16. CMYK • In Photoshop, when you change your RGB image to CMYK, you will probably not see a change on the screen • But it WILL be changed • Again, why do this step? Because if you don’t, when you send your file to a printer, they will charge you to do this conversion • When will you see a change? • If you use somewhat “neon-looking” colors • Do it now: change your foreground color, and notice the exclamation icon (out of gamut for print) • Can also see this under your Info. palette

17. Limitations of RGB and CMYK modes • CMYK is limited in color representation. • Most filters only work in RGB • CMYK doesn’t have nice pinks or bright greens • RGB’s yellows and oranges are lesser • Even though you're working in CMYK mode, your monitor is RGB so Photoshop is converting these values continuously (used to slow computer down)

18. LAB mode • Includes all of the colors that you can create in both RGB and CMYK modes. • Shows every color that the human eye can see • Device independent • Visual characteristics of these colors remain consistent on monitors, printers and scanners • Think about looking at a wall of TV’s- notice the colors are different even as they are all RGB- different devices produce different colors even if they are the same output devices

19. LAB mode = lightness, A, B • Broken down into three channels (plus composite) • Lightness (0= black, 100=white) • Other two channels (a and b) represent color ranges. • a channel contains colors ranging from green to red • b channel contains colors ranging from blue to yellow

20. Lab Continued • Photoshop uses Lab internally when converting between modes • Why use lab mode? • Larger range of color • Not defined by limitations of output devices like RGB or CMYK • Mainly used to tweak the value of files before they go to CMYK or RGB (especially color corrections)

21. Indexed Color • Only 256 colors • Compared to 16.7 million colors in RGB • Smaller in file size • Where would you use it and why? • On computer monitors and web pages for images that need small number of colors (e.g. buttons) • Limitations when using in Photoshop • Can’t use filters, layers, select, many tools, can’t save as jpg… • Suggestion for computer files, work in RGB and at last moment change to Index

22. Grayscale • Black, Gray (256 levels of gray) and White • Often, what looks like a grayscale image in a printed piece is actually CMYK made to look gray • It’s more expensive- Why do they do this? • Warms up the photograph- change through less saturation and more brightness • In Photoshop, reduced ability to manipulate image when in grayscale

23. Duotone • What is it? • Two inks (black + 1 color) used in print pieces • Why? • Want to try another, cheaper way than CMYK to warm up gray-scale looking images when I print them • Not used to simulate image- used to enhance grayscale • How to do in Photoshop (open up an RGB image) • Change to Grayscale (as intermediate step) • Change to Duotone (or Tritone, or Quadtone) • Select 2nd color (usually a Pantone color)

24. Bitmapped • Each pixel is either black or white • Most line art is this mode • Greatest limitations in this mode • How to do • Best to start from this mode (if you scan in something) • Also can do if you take a rgb image, convert to grayscale, and then play with the threshold, and then change to bitmap

25. On your own tutorials • More advanced tutorial on touching up an image with a person in it • http://www.lunacore.com/photoshop/tutorials/tut018.htm

26. Nice tutorial showing grayscale and masks • http://www.youtube.com/watch?v=vHBbklm4cuY&feature=related (4 minutes) – nice way to make a grayscale image • Can compare this technique (using the blue in the channel) to <image <mode <grayscale and you’ll see that this technique lends to richer looking blacks. • May use in project 1?