[ video from the isight, taken 02 Oct 2007, 127mm Mak-Cass, 20mm Plossl (77x) ]
So Darling Daughter #1 and I got ourselves up at 5am to check out the moon. It was a spectacular morning, warm, light breeze. Orion was high in the south, reminding me of March. It was much better than the previous day, which was our first choice but was clouded out.
DD1 is doing a science fair project that, in some ways, is a bit over her head. She was looking for an astronomy project, and I suggested measuring how high lunar mountains are from their shadows. She liked that idea, so we're going with it, but she is needing a lot of guidance and assistance.
I knew there were some guides for this project on line, so we picked one and she discussed it with her instructor. He was cool with the idea, with a little bit of simplification, so we're going for it.
Our first task was to pick a couple of mountains. Pico and Piton are typical for this project, so we went with those. Then I had her figure out what days would be good for decent shadows over the next three months. That will give her windows for planning observations.
The next task for her was to learn about the telescope. So we together set up the scope inside, and talked about the parts and what they do. Then I gave her a quiz on it, with a photo that she had to label.
The hard part about these kinds of projects is that I don't want to be doing it for her, or doing too much with her that she doesn't really learn what is going on. I'm hoping by end of the project she can set up the scope and take photos herself.
Being that this was her first time out with this scope ever, and my first time in about 18 months, and that we had a computer and camera and all that crap, I ended up doing a lot of the work for this session. I told her it was ok because this is how real astronomers work - they request data and a telescope operator acquires it for them.
So we hauled the junk out, did a rough polar align, and put the stuff together. We dialed in the moon. I turned the tracker on and things were ok... *whew*.
The next test was the camera, so while DD1 looked at the moon through the scope I set up the computer and iSight. I have to say that the little iGlasses plugin was the best $10 for this - we could not have controlled the camera enough to get a good pic without it.
77x was ok (see the movie), we could see the target mountains, but she was going to need more pixels. So I slipped the 2x Barlow on the camera adapter, and refocused. Glad we had enough travel for that. This is kind of a bastard setup now, we were getting a lot of vignetting because of the distance between the Barlow and the 20mm plossl. But, we could see the mountains and the shadows, so we were doing ok. Shot some more movies.
Then we tried it with the 10mm plossl. With the 2x in there, we were now up to 308x. That didn't really work for movies.
I did a "fly around" movie, stopping at some nearby craters. She'll be able to use these pics to establish a pixel scale. So our next step will be to pull some good frames, maybe stack them (but I don't think that will be really necessary), and measure the base craters and using a book determine the meters per pixel.
In reality she'd probably have to do this for each session, and there is actually probably better (more mathematical) ways of computing pixel scale, but I think as part of the simplification process she'll just do that task once to save time, and use the same pixel scale for the whole project.
Technically right now we have enough data to get rough measurements. I would like it if she were able to get out two more times in order to compare and average the results, just to see how close she can get to the accepted values.
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Comments [2]
Eh.
I still need to work on technique. If you want to call this a "sketch", then fine, I'll accept that. But it's not a "drawing" really. I don't think it qualifies.
And I'm not just being self-depricating. The edges around the black are weak, indicating where I didn't get in close enough with the shading. There are "blending features" - things that look like they could be either artifacts of the medium or actual lunar features. In a real drawing, there should be no blending features apparent.
Another thing I did was change the scale of this sketch from the outline I did at the eyepiece. Bad Idea. Except that the eyepiece outline was too small to be effectual. And I had noted positioning errors. For example, on the outline Angstrom (the little crater at the bottom) was too close to the end of the mountain chain.
So what I need to do is work on a scale that is more comfortable at the eyepiece.
This paper was my basic 20 lb bond from the printer. It worked ok, but I think it is just a bit too smooth. It was dusty - not holding on to the charcoal. Need to keep experimenting with that, too.
And finally, I have no clue what the grades of my charcoal are. For all i know, I was using "light" on the background, when I'd have been better served with "medium". On my list for xmas is a set of charcoals that I can pick the right grades.
Again this is all practice. Practice practice practice. I should also be drawing other stuff, too, just to keep working on techniques. But whatever.
So there it is. I didn't rotates this one at all, and i also didn;t do any post-scan processing. This is what it is. And it's upside down and mirrored, so it looks nothing like a map.
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Even thought it's been clear occasionally this past week, and warm even (for this time of year) I've not gone out to observe. It's been kind of a busy week all around, lots of activities and demands on my time. I've not even had time to start work on the final Prinz drawing.
The other night when it was cloudy I spent some time poking around the BAA Lunar Section web site - http://www.baalunarsection.org.uk/ . Not only is there another excellent tutorial on making lunar drawings, but I also was admiring the work of their members. The work of Nigel Longshaw was of particular interest.
It helps to look at these illustrations from a technical perspective and think about what they were seeing, what details they included of left off, and their rendering techniques.
A lot of the work, probably from the influence of Harold Hill, is in stipple. When I was in college, I took a full year of technical illustration. I considered it for a major for a while. I spent a large chunk of that time working in stipple because I liked the control it gave you. It requires good tools, however, so I invested in a set of Rapidograph tech pens (a serious purchase for a college kid). I still have them, though I suspect they are completely and hopelessly gummed up now, having sat with ink in them for nearly 20 years.
Even still, I'm not sure I'd use it for lunar drawings. I find myself more attracted to the continuous tone images produced with charcoal blending. And while I really like those done with ink wash, I think that attempting that is for some point in the future.
But first things first, as they say. Either tomorrow evening, which looks to be open, or perhaps this weekend I ought to be able to find a few quite hours to spend drawing. We're off to the farm this weekend, and I'm watching the forecast to see if will be work hauling either of the scopes along with.
November is the cloudiest month in MN, averaging only like 8 clear days. So far, we've not seen much of the sun yet.
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28 October 2005
I did another hour again this morning before work. This time of year, that works out pretty good. The weather is supposed to hold for tonight, too. These October high pressures are great. Frosty, but great. Not so cold this morning, but more humid - about 35F.
I really, really need to get the light shield made for my backyard. I was trying desperately to hide from the alley light, as well as the neighbor's kitchen light. Seems they get up at about 5, too. I was hunched into a tiny corner of my backyard, and I was still getting light in my eyes. Grrr. I came very close to putting the scope on the tower, but I wasn't sure if I could heft the mount up the "stairs" (a term which I use loosely). I also don't really know the condition of the stairs, and it would have really sucked to get to the third only to have it break while I was carrying the mount. So I opted to skip that. [This tower/playset was really intended to handle my dob, and the design is such that I can heft the individual components up first and then do up myself. It wouldn't really work with the tripod/polar head combination like that. Maybe I should build a winch on it.]
While getting set up and polar aligned is getting easier, I'm still making some mistakes that are a little frustrating. Today the batteries in my sketch board light were dead (they are rechargables). And I forgot my ipod. And the camera.
I went right to the moon when the scope was mounted. Oh the seeing is really terrible! Well, that shoots going to 300x. Today would have been the day for a 17.5mm eyepiece and the Barlow. Well, 150x (20mm plus 2xB) will have to do.
I began cruising the terminator, thought briefly about working up Gassendi but thought I'd save that for another opportunity when the seeing was better. I settled on the area around Prinz - a nice partially buried crater, some mountains and rilles near by, a couple of craterlets, a dome - seemed like an interesting place. Because my sketch light had failed, I wasn't all that sure how successful my attempts at sketching would be. I decided to grab the camera and pop off a few digital photos just in case. It seemed to work better than last time, I'm having a better time with managing the manual settings, and was able to do some pretty good brackets of the area. I've not looked at the photos yet, so they might all be mush for all I know.
Using my red flashlight I sketched for about 45 minutes. Because of the separated nature of the area, I was having a bit of trouble keeping things in the proper relation to each other. For this reason I hope one of the photos works. But I kept picking up details that I hope I can work into the drawing. I added Krieger, for example.
Mars was behind the house at this point, over in the west. I turned the scope on the Pleiades, but was disappointed (that is a wide field target, not really a good one for this scope). I then packed up and was wishing I could go beck to bed. Instead I got ready for work. Only when I had everything back inside did I remember I was going to try and find Bailly for tomorrow.
In the morning tomorrow, if it is nice (which it's forecast to be), I could pretty closely repeat Harold Hill's observation of earth shine on the mountains behind, right on the limb of the moon. So that is tomorrow's challenge, and hopefully a) its clear and b) the seeing is better.
PS - I did finally get around to fixing the RSS feeds for individual members on AstronomyBlogs. Since I'm pretty much the only user so far, it just didn't seem a priority.
Well, it's out there now, just use the little orange link at the top to subscribe.
PPS - I didn't blow the engine of my car (thankfully), but it is going to cost $517 (ouch!).
{above is an Apollo 15 image of the Prinz region}
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Above is my drawing of Lassell from this morning. For this one, i used a mixture of charcoal, conte and graphite. Suprisingly, I found graphite most difficult to work with. The charcoal and conte blended much nicer.
I also think this is not ideal paper for this project. I need something a little smoother that will allow the blends to happen more easily with less of the paper texture to come through.
On this one, I don't like the bright highlights on the sunward side. They need to start smoother.
I flipped this image after scanning it so that it was 'naturally' oriented.
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