Minor Project Background.
ASV 2022
Bubble Nebula NGC 7635 - HST
Last studio:
— rotate
— crop
Share and critique!
— image maker: What was your intention with
the image? Were you successful? What did you
learn?
— Others: Positive feedback
Our eye-brain system generates complementary
colours.
o
Should we base “reality” on our eyes?
» “In preparing for battle I have always found that plans are useless, but
planning is indispensable.” Dwight D. Eisenhower.
» You will modify your work as you go along but it pays to be thoughtful at
the beginning.
» Filters:

F336W Continuum UV

F555W Continuum Optical

F547M Continuum Optical

F791W Continuum NIR

F502N Emission line Oxygen

F656N Emission line Hydrogen

F658N Emission line Nitrogen

F673N Emission line Sulfur
Plan.
Keep Notes
How are Optical Images Made?
Light passes through a filter in front of
the satellite's instrument. This
produces black and white images for
parts of the spectrum of
electromagnetic radiation (which
includes light).
Visualization techniques:
Composition and Colour Harmony Play a role
Which part of this image jumps forward and which part falls back?
Visualization versus Scientific Meaning
Composition and Colour Harmony Play a role
Which part of this image jumps forward and which part falls back?
You will pick colours to give your image depth.
Visualization versus Scientific Meaning
Composition and Colour Harmony Play a Role
How is your eye led in a picture?
V. Van Gogh
Visualization versus Scientific Meaning
NGC 2207 and IC 2163
Conventional north up and east to the left
Visualization versus Scientific Meaning
Hubble Heritage Orientation
You can rotate and crop an image.
Colourize Data using Simple Colour Wheels
These are useful for selecting colours to make harmonious compositions.
Note the relationship between the additive and subtractive systems.
Compensating Tones
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".
Seven Colour Contrasts
These 7 colour contrasts, described by Johannes Itten (1970,1997) can be used in
conjunction with the colour wheel based on Newton's experiments.
Seven Colour Contrasts
Steps for your Minor Project.
Fire up GIMP! (Take Notes!)
1. Setup layer file (.xcf)
– Make new file with black background
– Copy thumbnails into layers with screen mode
• Copy visible, paste, name, set mode = screen.
2. Colourize each layer
– Copy layer, turn off original
– Use levels tool to select colour in active
layer
3. Adjust colours
– Curve tool
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
6. Orient
7. Crop
8. Cosmetics