I got tired of (more like, going out of my mind) waiting for my new set of papers to start another painting, so I decided to do a small demo as a value exercise on a left over piece of paper that I had dug out. This photo of the sweet smelling lilacs is contributed by ‘onefromheaven’ to the RIL of wetcanvas.com. I like this combination of white-pink-lilac.
These lilacs are in strong sunlight and its fairly easy to observe the values. Not only does each individual floret in a cluster have core shadows within them, but the cluster as a whole also has highlight/core shadow regions. The light rays are falling on them from the top right, so the shadows are cast towards the left, bottom of each cluster. The highlights are on the top, right of each cluster (except when there is a cluster above it which then casts its own shadow on the one beneath, so the highlights are in part in shadow e.g the two violet clusters at the extreme left). If you are short sighted, you will see the light-dark areas better if you remove your specs and then observe (the details are lost, so that there are only blocks of color). Squinting also works. I made this rough sketch on a 14*8 inch paper, (also indicating the shadow regions) soaked it for 2 mins in clean water and taped it to a board and left it to dry.
I then mixed puddles of ruby red+ pthalo blue, magenta, magenta + pthalo blue, sap green, aureolin yellow, yellow green and hookers green. I wet the paper evenly and dropped in the colors taking care to leave the flowers white. If your paper allows it, it will still be wet and you can go ahead with the next step but if its beginnning to lose its shine, stop and leave it to dry thoroughy. Ruby red+pthalo blue makes a somewhat subdued violet and I used more of this for the background. I also used this mixed with a little yellow for shadow areas in the next step.
For the white flower cluster on the top left, you can see the shadow area at the bottom. For the pink one, I wet the area and dropped in magenta and magenta+pthalo blue. The highlight area is towards the right. Similarly for the other flowers. Painted in some leaves roughly.
Make some positive floret shapes and some negative ones (outline a floret and wash away the edges). Hookers green is quite opaque and gives a nice dark color mixed with a bit of the violet mix. I outlined the top of the white cluster and washed away the edges onto the background area. Added some dots of yellow for the centers of florets in the highlight and raw sienna /green for the florets in shadows.
I wet some of the leaves and added some darker colors and also cast shadows and veins.
It helps to paint something that you like and are interested in, beacause then you have already seen it real life and know the 3-dimensional form of it. Only then does it make sense to paint from photographs.