Telescope Reviews: Jupiter manipulation tutorial

As I've gotten some interest as to how I'm getting my Jupiter sketches looking the way they do, I thought I'd post a bit of a tutorial as there might be something useful.

First of all, I've come up with a sketching template that has the rough locations of the major features. The lines are a red tint that's only a half point in size, so they end up not showing through the sketch. Here's a pdf of my most recent template.

While sketching, I just let my bands continue past the edge of the planetary disk, concentrating more on the gradations and shadow features along the way. I bring this into the computer, straighten it out, and convert it to greyscale.

I use the circular selection tool to create the shape of Jupiter, based on the outline on the template. I invert the selection, create a new upper layer, and fill it with black.

On the sketch level, I run a "Reduce Noise" filter, to try to reduce the grain of the paper and the individual pencil lines that did not blur out with a smudge stick or tissue.

I then duplicate this layer, run a slight horizontal motion blur on it, and reduce the opacity to allow some of the unblurred layer to show through.

Then, based on notes I've taken, I adjust the levels of the overall image and then within the bands themselves. This allows me to sketch features at full value, knowing that they will be compressed later.

On a new layer above this, set to "Color", I put down horizontal bands of color and then adjust them based on notes and memory, trying to concentrate on whether adjacent bands are warmer or cooler than each other. At the poles, I may lay down a gradation of color.

To reduce the cartoony aspect of it, I blur the entire layer and then dial down the opacity. I can also use the rectangular selection tool with a high degree of feathering to re-select areas and change their hue or saturation.

I then dupe the upper black layer with the circular cutout and use the layer effect "outer glow", picking a medium grey with a bluish tint at 100% opacity applied as "normal". This layer obscures the detail at the edges of the planet and starts to give it a rounded look.

Duping this layer, I take the upper of the two and go back into the "outer glow" settings, this time picking a deep bluish-black and setting it to "multiply". You may have to go back and forth between these two layers, adjusting the size of the gradients until it just feels right.

Now go to your top-most mask and apply a slight blur to it, softening the edge of the planet. Then do the same thing to the next layer that has the black/blue "multiply" glow until you get a natural feel.

At this point, you're essentially done. Just reduce it in size, add any moons, etc. You'll be amazed at how nice these look at smaller sizes. Only the best of nights can hold up when they're large and this isn't one of them! - j

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