Tools and Techniques Category

Last month's presentation at NCRAL went really well. On Friday night, a group of about 35 attended the workshop where we practiced deep sky (M51/NGC 5195), planetary (Jupiter), and lunar (Cassini Crater: Thanks to Mike Wirths for the use of his image) sketching. Each attendee was supplied with sketch templates...
Next Friday and Saturday - April 29 and 30 - I have the privilege of conducting a workshop and speaking on astronomical sketching at the 2011 NCRAL Annual Convention in Green Bay, Wisconsin. Details about the convention can be found here: 2011 NCRAL: The Amateur Strikes Back The Astronomical Sketching...
One of the great values I attach to astronomical sketches is that they can help convey what an object looks like visually much better than a photograph can. However, there are some caveats I've been wanting to discuss. What you see in a well-executed sketch is not necessarily what the...
The June issue of Astronomy Now is now available. This month's column features the colorful double, Struve 2259 in Hercules. Subject:Struve 2259 Issue:June 2009 Astronomy Now Basic Media:White ink marker, white pastel and colored pastel pencil on black paper. Featured Technique:Using white ink along with white and colored pastel to...
When I took up amateur astronomy, I did it with the dual purpose of satisfying my own boundless curiosity about everything cosmic, AND to share that interest with my family. My 6 inch (150 mm) SkyView Pro Newtonian has served that first part perfectly. But it turned out not to...
Table of Contents Introduction What you will need Scanner peculiarities To invert or not to invert Sizing your image Dealing with a color cast Inverting the image Adjusting luminosity and overall color The levels dialog The black slider The white slider The gray slider Setting overall color Image cleanup Adding...
To invert or not to invert Another question you will want to consider is whether or not to invert your scanned image if you are sketching on white paper. For the purposes of this discussion, the word "invert" refers to changing a positive image to a negative image and vice...
Dealing with a color cast Check your sketch to see if it has a color cast (yellowish is pretty common). If it does, you can easily fix it by converting to grayscale and then converting back to RGB. Recent versions of Adobe Photoshop also have a command at Image >...
Adjusting luminosity and overall color (Continued) Now, I'm going to make a suggestion that you don't have to follow. You can either lighten the background of the entire image, or you can choose to lighten just the area inside your sketch circle. I prefer to lighten inside the sketch circle...
Adjusting luminosity and overall color (Continued) The black slider The black slider (Fig. 17, D) is the touchiest one, and has a very limited use in my experience. Its job is to mash all the almost-black values down to black--or whatever not-quite-black value you just entered in the "Output levels"...
Image cleanup If you are like me, your sketches will have some unintentional flaws. I leave it up to you whether you want to "Go Commando" and leave those rough edges in for a more raw expression of your work. I respect that. (You buy organic don't you ;-) Now,...

Digitizing Tutorial - Page 7 of 7

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A note on saving Photoshop will allow you to save JPG files through the normal save menu, but using the "Save for Web" menu can substantially decrease the file size of some images. I would encourage you to use this option to treat your visitors to shorter load times, and...
The way the contours of this galaxy danced and materialized with increased dark adaptation, averted vision, and patience was particularly enjoyable. When I first centered my telescope on the galaxy, it was easy to spot and appeared elongated with a strongly condensed core. With time spent at the eyepiece, the...

Double Star Sketch Update

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I haven't been able to get out for any observing recently. But I have been up to something. In case you hadn't noticed--and I know you have--I'm working on a double star project right now. In the process, I felt the need to come up with a consistent method for...
Table of Contents Introduction Step 1 - The Observation Step 2 - Sketching The View Step 3 - Scanning, Inverting and Cleaning Up the Sketch Step 4 - Softening Star Edges Step 5 - Adjusting contrast Step 6 - Adjusting White Star Cores Step 7 - Adding Color Step 8...
Step 4 - Softening Star Edges To lay the groundwork for adding color to the stars, I like to soften their edges a bit. The coloring method I use causes color to adhere to varying shades of gray, but leaves the white areas alone. If the star has a pretty...
Step 7 - Adding Color Now comes the fun part--aw heck, it's all fun, right? Anyway it's time to colorize the stars as you described them in your sketch or notes. Grab a soft paint brush that is slightly larger than the star, set the paint brush to "color" mode,...
Step 8 - Adding Additional Glow This last step is a bit of a personal preference. I like to add an additional soft glow around brighter stars to enhance the sense of brilliance. To do this, select a soft brush that is 2 to 3 times the diameter of the...
Subject:Messier 51 (NGC 5194/5195) Issue:April 2009 Astronomy Now Basic Media:Graphite on white paper Featured Technique:Use of blending stump and kneaded eraser (putty rubber) to build progressively fainter details in a sketch. Suggested Materials: Strathmore 80# drawing paper 2H and HB drafting pencils Blending stump White plastic eraser Kneaded eraser...
After discussing how the annular appearance to the coma of 17P / Holmes may be an illusion, a very good point was raised. I was directed to some images of the comet that very clearly show a distinctly brighter ring around the edge. Checking values in Photoshop showed that these...
After catching glimpses of Supernova 2005cs in M51 last week. I thought I'd have a try at photographing it. It's been 10 months since I last hooked the camera into the eyepiece and messed with imaging something. (Piggyback wide-field shots are so much easier =) Anyway, I learned a few...
A few months ago, I invested in a Meade 12 mm Astrometric Eyepiece that I could use in measuring double stars. I calibrated the eyepiece scale in June, and have used a few times since them. I'm definitely at the novice stage of using this eyepiece to measure doubles, but...
7) Insert the barlow through the hole in the protractor disc to check for fit. The fit should be snug and some twisting and wiggling may be needed to insert it the first time. If it is too snug, use your knife to evenly trim out a bit more material...
Calibrating the separation scale 1) Pick several stars from a list of calibration doubles. The table on page 3 of Ronald Charles Tanguay's article "Observing Double Stars for Fun and Science" is an excellent resource. Look for wider doubles to help reduce estimating errors. 2) Rotate the eyepiece so that...
What motivates an amateur astronomer to hunker down over an eyepiece and draw what they see? Have you ever looked at an astronomical sketch and wondered why the artist handled it the way they did? If you are a long-time astronomical sketcher, you probably have a some goals and methods...

Observation Logs and Sketching

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Well, after a couple months of observing, and getting a feel for how I like to observe, make notes, and sketch, I set up a couple observation sheets that fit my style. I thought I'd show those here, so you can see how I make notes when I'm outside freezing...
Belt of Venus Observation Record Sheets Note: although the sample images of filled-out record sheets below have my name printed on some of them, my name is not printed at the top of the pdf files. General Astronomy/DSO Record Sheet (Click thumbnail above for DSO Record sample) US Letter Size...
I can't remember the last time I picked up a paint brush to create something I found inspiring. It's been too many years, that's for sure. After a few years of creating technical illustrations of my observations, I've really gotten the urge to do something a bit more creative...
Since the Orion image I just posted was such a major project to process, I thought I should post my processing steps here for posterity, suggestions, or outright criticism. I definitely have room for improvement. Here is the initial image that consists of 3 stacked images to help average out...

Sketch Lighting

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Since it's been so cloudy lately, I've been working on a solution to my DSO sketch lighting. Up to this point, I've been laying the red light on the clipboard and trying to slide it around and keep it from falling off at the same time. It is a pain....

Sketching Close Double Stars

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Eric Graff from Cloudy Nights contacted me recently and raised some excellent questions about a few double star sketches that I posted last week. They touched on concerns that I've been mulling over since I posted them. You see, the Astronomical League double stars I've been working on are filled...
Even though I've been sketching my whole life, my recent experience with sketching at the eyepiece has introduced me to a new set of interesting challenges. The biggest issue issue is seeing your sketch area while not ruining your dark adaptation. I've got some info on sketch lighting here....
Next I pick up a blending stump and scrub it in the dark patch to pick up enough graphite to paint in the light object. Before using the blending stump as-is, I'll usually test it out somewhere outside the circle to be sure it isn't too dark. If it...
Now comes the tidying up stage. If necessary, I'll break out an eraser and deal with any overzealous object boundaries, or to give a harder edge to an object that is too soft. Finally, I make sure I've marked in the remaining cardinal directions, and other details I feel...
When I was preparing the open cluster section of the Astronomical Sketching book, I put together a tutorial covering the Double Cluster in Perseus. In the end, I decided not to include it in the book in order to allow room for some other important content in that section. This...
Step 5 - Filling out the Cluster: With the core of NGC 869 complete, I began to spin my way outwards, looking for triangles, parallelograms, rhomboids and other proportional relationships to use in positioning the stars. (See Figure 5) As you begin to add more stars, it becomes easier and...
Step 7 - Finishing the Sketch: Because the warm glow of orange stars was an important part of this beautiful view, I made sure to note those stars. For simpler sketches, these can be described in your written notes. With a complex cluster like this, you could go through the...

Stargazing Glasses

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A couple months ago, I got around to testing some diopter flippers I borrowed from my optometrist. I was really REALLY impressed with the clarity they gave my naked-eye observing. I had the results of my test quickly digested into a set of stargazing glasses. I ended up requesting an...

Tools

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So, as with any hobby that involves 'equipment', there's that temptation to get hung up on all the cool toys, right? And then take pictures of them all dolled up and arranged just so...Well, I'm not going to pretend that I don't breath-and-sleeve-shine my scope with a twinkle in my...

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