Sometimes, when Rob finds me bent over one of my drawings for extended periods, carefully filling in great spans of white paper with layers of black sharpie, he'll ask if I've ever considered painting white lines on black paper instead...which would presumably save time and effort. Or why not just adopt a digital format...enabling easy inversion from black on white to white on black...or back again and a mixture of the two? What effect does method have on the final product? How would the appearance of my work change? Would my vision itself become different? Would the quality of line be altered?
Why not start with some simple inversions. Take a picture of a galaxy...
In this case, a Hubble image of NGC 1300 in the constellation Eridanus (the river). If I were to use my usual method of blacking in space on a white paper, this would take forever. Instead, I created a "negative." Using different sizes and spacing of dots, I made the brightest areas the blackest, while also trying to leave white areas for dust lanes and background space. Making those internal white areas appear natural and flowing, as they do in the photo, was the most challenging part. I only hoped that things would look a little better with the inversion.
To invert the photo of my drawing on my mac, I opened it in preview, selected "tools," and "adjust color," and then slid the top black slider all the way over to the right, and the top white slider all the way over to the left...
Ok, that's interesting.
I see now where I could've refined my detail even more...spent a bit more time getting all those intricate dust lanes to come out. Still, the whole process only took about 1/2 hour, and it came out looking alright...not really identifiable as NGC 1300, but a reasonably clear illustration of a spiraling galaxy. I'll bet I could improve my technique with practice too.
Now for something to help illustrate the concept of "averted vision."
Text from the packet:
"Objects like the moon, bright planets, and many stars are usually easy to see, but when you're observing a very dim object like a galaxy, nebula, or even a faint globular star cluster, a technique called "averted vision" will help you see in much more detail. Rather than keeping your focus in the center of the field of view, instead try looking toward its edge, while simultaneously directing your attention to your peripheral view. You will be amazed at the details that emerge!"
Below is the original "negative" version of the drawing, in which you may recognize the Andromeda galaxy as the subject under observation. There was still a lot of white space to fill in around the edges, but with most of the detail existing in the center, I still saved time and effort. I'm pleased with the result here. Again, not exactly gallery-quality, but perhaps an effective illustration.