Depicting luminosity using paint

• 1
  If you were painting this, you would paint the background clouds before adding the sunrays.Thinkstock/Comstock/Getty Images
  
  Paint the background first. If you will be depicting a bright object directly, it's best to start with the dark background surrounding the light source. Very dark colors like black work best, if that fits in with your painting. However, there are exceptions to this rule when the object is extremely bright. For example, if you are painting the Sun, the whole sky will be illuminated, so paint accordingly. Wait for this background layer to dry a little.
  
  
• 2
  The radiant object is a solid block of light colors surrounded by a dark contrasting backgroundSiri Stafford/Stockbyte/Getty Images
  
  Paint any radiant objects using a very bright, light color such as white, light yellow, electric blue, or orange. In most cases, radiant objects are more or less uniform in color. The perception of brightness is intensified through contrast.
  
  
• 3
  Note the aura around the bulb. However, also note, this example does not look very realistic, because the painter fails to have a contrasting background.Photos.com/Photos.com/Getty Images
  
  Paint an aura, or glow, around the radiant object. This aura should be approximately intermediate between the color of the radiant object and the background, and should be a gradient that gradually becomes increasingly similar to the background as the distance from the radiant object increases. See the light bulb in the first example.
  
  
• 4
  The shutters create an interesting pattern of light and shadow on this object.Jupiterimages/Polka Dot/Getty Images
  
  Finish the rest of the picture, and remember, a radiant object casts light and shadow on everything nearby. This is the most challenging part of your job as a painter. You will need to visualize which side of the object would catch the light, and which would be thrown in shadow.