[ 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.
| Lunar |
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Thoughts on Pluto...
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First of all, I finally got off my ass and sent the TrueTrack back to Orion. Hopefully, I'll get that back in a few weeks and be able to do some observing before the snow flies. Not that I'll have any time.
...
A couple of weeks ago I bought an iSight for my mac. I needed a webcam and mic for some client work, and it seemed like a nice unit.
It was sitting here on my desk, when I though "i bet someone has connected this to their telescope." A quick turn of google and this came up.
Interesting. I always get disappointed, however, when I see the phrase "my buddy machined a few parts..." I don't have a buddy that can machine custom parts easily.
I took a look at what he was doing, and then thought about what I have kicking around that could also work.
First thing I've got is an Orion 35mm camera adapter - the one that can be set up for eyepiece projection. So there is a start, I could put the eyepiece in that. The opening of the eyepiece projection is too big for the camera, so when the camera is in and up against the eyepiece it flops around, which would not due.
My simple solution was to wind a strip of paper around the end of the camera, then secure it with some tape. That is the small ring in the above photo. By using paper, I could then slip the ring on and off the end of the camera.
The o-ring isn't really necessary and it was just on their from an earlier experiment.
I tried all this out with my 125mm Mak-Cas, and (during the day, at least) it worked quite well. For an eyepiece I used a 20mm Televue Plossl.
The camera tended to over-saturate, however, but i was able to compensate somewhat for this by loading a little program called iGlasses which allows a lot of control over the camera. Especially nice was the ability to turn off the auto-focus. I also tried putting my neutral-density filter on it, and that helped a bit, too.
I'm not sure how well this will work after dark, mind you, so that is the next experiment. My main target will be the moon. The point of this was to shoot a short movie (series of stills, actually, is what i want) that I can use for reference when doing sketches.
I do really like to be able to put my stuff together and make additional use out of all of it. In the grand scheme, I doubt that this is of much use as an astronomical set up, but it should be fun on bright targets.
| Equipment |
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I got the mak out for the first time in a long time last night. It was a beautiful day and very pleasant evening - pretty ideal for observing. I was tired, though, so i wasn't sure how long i'd last. I was hoping to have a go at comet 73P SW as well as a lunar sketch.
After getting the stuff outside and set up at about 9:30, with a rough polar align, I realized right away that tracking wasn't working right. It appears that my RA motor is running backward, and I've got no idea why. I tried all kinds of things, then gave up and came inside and played with it more there until 11:30.
Playing with it inside, I'm somewhat what convinced that something is faulty. No matter what setting - north or south - or which button i push on the controller, the motor runs CCW when facing the gear. If I set it to 8x, it goes 8x CCW. If I set it to 2x, it goes 2x. But both buttons turn the motor CCW no matter the N/S switch position.
I have a couple other things to test, but it might be a call to Orion tomorrow to see what they have to say. At least the drives are under warranty still.
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In the past I've toughed out winter observing. Now, I can always find something else that is equally important. So I'm just kind of waiting for winter to end. I thought we were going to be rid of it a couple of weeks ago, as sometimes by mid march the snow is gone and the temps begin to moderate. However, last week we got 17 inches of snow.
Since then, it's been cool - not cold but not the kind of warm it needs to really knock the snow down. So the snow lingers and everything is kind of in a state of drippy wetness.
My goal at this point is to try to wrap up some development projects and updates so that when the nicer weather does roll around I don't have to be chained to the machine, as it were. For example, I loaded a couple of new templates to the blog system, as well as got the categories working (see the little folders at right). I've got most posts sorted, but i need to go through them again... There are other things as well.
I was thwarted in my efforts to take a drawing class again. Once again it conflicts with Tae Kwon Do, so no joy in the spring (TKD gets priority).
I am looking forward to some nights outside as it gets warmer, sketching craters and comets, and getting back to the farm. I need to fix the observing pad (get it pointed north) and maybe set up some wind breaks. Get on with a few of those construction projects like the astro-potting table and an observing chair.
The snow can melt now.
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