open letter to students

1. open letter to students keep studying by following the detailed topics list University can’t punish you if you support us by not crossing picket line.

2. Bubble Nebula – NGC 7635 Phys 1830: Lecture 15 • Goal: Explore how to construct a public outreach image. • Within each public outreach image is the struggle between scientific meaning and visual aesthetic.

3. Composition: The goal is to keep the eye inside the picture plane. Monday: work on composition

4. Cool colours are bluish in art but reddish in science. Warm colours are reds and yellows in art but blues in science. Who is your audience? How do you want your picture to be read? Select colors with this in mind. V. Van Gogh

5. Tints, Tones, Shades Pure Hue Tint: Add White Tone: Add Grey Shade: Add Black

6. Tints, Tones and Shades  Illumination Effect Use any colours for the background but add grey to make each of them a tone of the same value. Then add a bit of white to a pure hue to make a tint. This tint will appear to glow as if it is a neon gas.

7. These are useful for selecting colours to make harmonious compositions. Simple Colour Wheels Based on a colour wheel by Newton, these are renditions of the same relationships.

8. A powerful way to modify a colour. For your chosen hue, pick its complement and add that complement to the hue. Compensating Tones

9. Here's an example using warm blue (cyan) and a shade of its compensating tone (orange) to have "blue come forward" and "red go back". Create a foreground, middleground, and background: Today: Select colours and adjust in layers.

10. Visual Grammar: • We learned that visual grammar can be very powerful. • Would the artists in the class like to share any tips?

11. Visualization stages: 1 - Greyscale Stretch • Convert ~60,000 data levels from FITS format data files into 256 grey levels in ppm, tiff, or jpeg. • Jpeg images are provided or use your own stretch. (Note lighting can modify the appearance of colours.)

12. Visualization Stages: 2 – Assign Colours • Keep notes on your strategies so you can • repeat your steps if something goes wrong • compare your colour experiments • review your work with others • prepare for the test • Consider what your visual goal is. Get your team members’ full names and emails now. Designate a note taker.

13. Visualization Stages: 3 – Combining

14. Visualization Stages: 4 – Orientation, Cropping, and Adjusting • Adjust your layers and then your merged image to enhance your contrasts • Orient to lead your eye • Crop to make a dynamic image • Critique

15. A Recipe for Cooking Up Astronomical Images • Cooking Up Astronomy Images Online at http://astronomy.swin.edu.au/sao/guest/english/imageindex.html

16. B is called blue but is purple (i.e. blue-violet) R is called red but is orange (i.e. red-orange) Goal: Select colours to make a harmonious final image. That is, generate a final image with complementary colours, greys (not browns), at least one of the 7 contrasts, etc. Simple Colour Wheels

17. B is called blue but is purple (i.e. blue-violet) R is called red but is orange (i.e. red-orange) The additive system adds to form white. State to yourself the primaries in the additive system. State to yourself the secondaries in the additive system. Confirm these with your team. Questions? Simple Colour Wheels: Preparatory Exercises

18. Putting the colour wheel in context: • What is the complementary colour of your favourite colour? • If your favourite colour is a primary colour, which system is it a primary in? • Pick 2 colours that are harmonious with your favourite colour.

19. Review: • The complement of the red-orange in the RGB system is which primary colour in the CMY system: • Magenta • Cyan • Blue • Green • White • The RGB system has as its primary colours • Red-orange, Blue-violet, yellow. • Red-orange, Blue-violet, green. • Cyan, magnenta, yellow.

20. RGB additive system: • What 2 primary colours when added together produce cyan? • Magenta and Yellow • Green and Blue • Red and Green • Blue and Red

21. Which of these contrasts interest you and your partners? Seven Colour Contrasts

22. Seven Colour Contrasts

23. What contrasts does your team plan to use? Write this down!

24. Summary: • Composition Considerations: • Lead the eye to keep it in the picture plane. • Create a foreground, middle-ground, and background. • Consider how the image will be read in terms of temperature, etc. • Colour Considerations: • Harmonious colours work with the viewers’ physiology. • Optical effects can be used to help explain the science. • There are 7 colour contrasts.

25. Fire up GIMP! (Take Notes!) • Setup layer file (.xcf) • Make new file with black background • Copy thumbnails into layers with screen mode • Copy visible, paste, name, set mode = screen. • black background layer helps reduce noise. • Colourize each layer • Copy layer, turn off original • Use levels tool to select colour in active layer • colour need not be what your eye would see; consider aesthetics and visual grammar. • Adjust colours • Curve tool • helps reduce noise, increase detail and harmony.

26. Fire up GIMP! 4. Create single layer file (.tiff) • Make new file with black background • Copy visible from .xcf file and anchor, flatten. 5. Adjust colours • Curve tool • generate striking images 6. Orient • Crop • both 6 & 7 guide the eye. • Cosmetics (remove cosmic rays & noise) If you are ahead of the class, do a different colour rendition! See if it works better.