April 2009 Update

The May 2009 issue of Astronomy Now is out. The Drawn to the Universe column in this issue features a graphite sketch of M3 which focuses on using stippling technique to convey granularity.

While preparing for upcoming issues, I've been working with a wider selection of materials and techniques so I can present readers with a variety of approaches. I rely a lot on digital tools to convert my graphite drawings from negative to positive, to add color, and perform cleanup. It's fast, efficient, and I'm really comfortable with Photoshop's interface. However, using a computer to manage sketches is not for everyone. So I want to cover methods for producing positive drawings and include color where appropriate without the need for a computer, scanner, software, and all the techno-training that goes with it. So keep your eyes peeled for the June issue--I hope you have as much fun with it as I did.

That doesn't mean I'm giving up my digital process though. In fact, I've been batting around some revisions to my double star method. I'm growing a little tired of the choices I made to convey magnitudes. The brighter stars are just too big, and I think it detracts from the appearance of tightness on the closer pairs. This weekend, I finally finished charting and testing a new magnitude structure for the main field-stop portion of the drawing. I'm cutting the maximum star size by about a half, and conveying brilliance by moving that light into the surrounding glare. I played a lot with noise settings in the halo to be sure the artificial-looking stair-step effect was reduced as much as possible. Looking at my new scale, stars from -1 to +12 mag show a lot more difference in brightness. One of the nicer benefits is that pairs with a significant magnitude difference appear more difficult to resolve in the final drawing, which is truer to the eyepiece view.

I also reworked my airy-disc detail setup. Somewhere along the line, I started scaling the diffraction pattern detail images smaller, so it's harder to see them. I'll be boosting those larger, and have made some improvements to the diffraction pattern template I'm using.

I've got a backlog of double star sketches that I've been holding up until I could get all that finished. So, hopefully I'll start kicking those out soon.

...and I sense a new Coronado PST getting loaded on a cross-country delivery truck any moment now. What better time to step into H-Alpha Solar observing than when the sun is in the midst of a significant minimum!

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About this Entry

This page contains a single entry by Jeremy Perez published on April 20, 2009 6:01 PM.

Drawn to the UniverseMAY 2009 - Messier 3 was the previous entry in this blog.

Mottled Galaxies is the next entry in this blog.

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