Taking the night off to go dancing. At least metaphorically.

Trimming things up

Now that I know the astro rig works it's time to start cutting. The thing was made to hoist a telescope, which means it had space for counterweights, an extra axis, and of course was meant for the (relatively) hefty tripod that it came with. I lathed, chopped, and heli-coiled the poor bastard until it was just what I needed (and stronger at all the attachment points), and mounted it to a carbon fiber tripod:

Carbon fiber is a lovely material, very strong and stiff, but this not-too-expensive tripod sacrifices strength for weight. It's light, but not as light as it could be. It's strong, but not as strong as it could be. My plan? Tension it to the ground so that it gets the most out of the linear strength of the legs. First step was to remove two of the telescoping sections from each leg and then create a ground spike to keep the legs from spreading since I intend to put a pretty substantial amount of force to pull it to the ground:

The flats are lathed from 6061 aluminum and tightened in the same way the original legs were, so there is no issue swapping back to the stock configuration when I want to use this tripod for more...conventional things. All in all I cut about a pound out of the whole rig and it's come up stiffer and stronger than it was. Can't wait to see how solid it gets when it's properly anchored to the ground.

Not everyone is excited about this setup. The brother thinks I'm taking too much flexibility out of my tripod setup. I don't see this being an issue, but we'll see. I'd rather this and be able to take pictures of the things I want to than waste all my carrying capacity worrying about what I might get surprised by. Right now I think I need to chop about 5lbs out of what I think I'm bringing with me. Which is, ironically, slightly more than the entire astrophotography rig (without camera).

What can you get with the hacks?

Now if you've ever even shopped equipment for star tracking you've got to be asking a question such as "yeah, $100 worth of stuff with most of the useful parts hacked off. You're going to align this thing by eyeballing it and then calibrate the rotation with no equipment, and you expect to get something?"

Well...yes. But I admit that's a fair question. However I pretty much have to if I want this to work for my trip (and hopefully subsequent, possibly more ambitious trips). After a night of test and practice?

(Orion Nebula, 300mm F5.6, ISO 200. Composite of eight 45second exposures)

I was also able to capture Pleiades and Andromeda Galaxy, but this image was my favorite. Note that it was an especially clear night for being at sea level, and I was able to filter out most of the light pollution. The latter part should be even better at altitude and in the middle of nowhere, assuming we get lucky on weather. Fingers crossed.

Getting serious

In the last post I talked about some of the big problems of taking pictures of the dark sky. This post is about the solutions. I can solve two of the three problems: we are moving (so the sky appears to be in long exposures and high magnification), and high sensitivity means more noise in the sensor.

By moving the camera with the sky one can take very long exposures at high magnification, and therefore not need to use high ISO settings to gather a lot of light. First we need to control the camera; The Nikon D90 doesn't natively have a setting for more than 30 seconds of exposure per button press. It does, however, have a "bulb" mode that allows longer shutter times. Also it would be nice to take multiple exposures without having to touch the camera, as well as program in some delay before starting so that any fiddling doesn't leave the camera shaking when the shutter opens. Solution:

Ebay, $32. Intervals, exposure times longer than I would ever want to, delays, ability to repeat the shot without having to touch anything.

Now about the tracking; normally when you want to get in to this game bigger is better (on some level). Heavier, harder, larger bearings mean less shake, more precision, and overall better images. It also means more expensive. The good news for me is that I'm not trying to compete with Hubble, just engage my spirit a little, and I've also got to be very size and weight conscious since I intend to lug this thing a long distance.

For these reasons I picked up a Celestron CG-2 equatorial mount off of ebay for a whopping $60, and a not-so-matching drive motor for it. An equatorial mount works by having one axis that matches the rotation of the earth in order to counteract its motion. Normally this has all kinds of other adjustment stuff on it to assist in pointing a telescope, but that very basic part was all that I need, plus a way to mount the camera itself. I chose to hack off all the parts that mounted a telescope, counterweight, and whatever else didn't serve my purpose and simply mount the same ball mount I use for all my tripods:

(some of the extra bits removed)

(The result)

I had to "manipulate" the mounting system for the drive motor using a universal adapter (hammer) and create a a couple of new parts in order to mount the ball head in a simple and removable way. All in all I'm pretty proud of my work and it's plenty solid enough for my purposes. It lacks all the things that make a real imaging system like guide scopes, autoguiders, heavy counter weights, adjusters for other directions, etc, etc. Once in the field I'll have to set up without any of the normal accouterments, calibrate on the fly, and hopefully be off and running without too much trouble.

Next? Testing and practice...

Where the stars are...

Climbing is training, so that will be an ongoing thing. Now I have something of a base understanding of where I am, and some idea of the holes in my abilities. I'll work on those, and then check back in with the climbing gym a few times between now and the trip to judge my progress and latest weaknesses.

Taking pictures of the sky is complicated. Three major problems:

• It's dark. Dark things are hard to photograph. This requires extreme sensitivity, extreme light gathering ability, or extreme gathering time on the part of the camera. Generally a good mix of all three.
• We are on a big moving thing, and so if you plant your camera firmly on the ground the sky slowly shifts during the course of a long exposure. The higher the magnification the more noticeable this is for any given exposure time.
• Light pollution sucks, and so does being at sea level for the purpose of this. Where I am there is 32 feet of water above me filtering out a great deal of starlight. This makes things darker to start with, less stable as the atmosphere shifts about, and plenty of material for the light pollution of my nearby city to muddle up.

To get the hang of things I started out by putting my trusty D90 on a firm tripod to toy with exposures and settings. Things of note:

• With a 300mm telephoto lens an exposure of more than about 4 seconds turns the stars in to streaks. With an 11mm wide angle this takes more than 15 seconds.
• higher ISO (light sensitivity) can be great, but it also has some flaws. This drives the sensor harder, and the result is more camera noise and grain for a given exposure length.
• At some point you've gathered enough light that the light pollution becomes a dominant effect and longer exposures or higher sensitivity are only detrimental.

Results? Here's the result of a 15 second exposure at F2.8, ISO 500 using a Tokina 11-16mm wide angle lens. Color correction done in Lightroom, otherwise the processing is minimal:

Clouds didn't help, but that's Jupiter toward the bottom shining bright. This was a productive couple hours of practice and testing, but next up is taking this up a couple of notches...

What first?

There are so many problems to tackle. There are almost certainly problems that I have no idea I need to tackle, and I already can think of a lot of problems.

• Don't know what other climbing walls or real life boulders are like. Other climber friends talk about "5x10" and "v4" and all this other jargon I've never heard of before. Who knows what major parts of climbing I'm missing.
• The last time I did anything with pointing a camera at the night sky it was mounted to the back of a 24" asteroid hunter inside an observatory. This has basically nothing to do with amateur astrophotography and everything to do with image processing and math problems.
• I own relatively little gear that is suited to distance hiking. And by limited, I mean I've got a fleece and a gortex rain jacket for biking that are probably pretty solid bets.
• Camera gear is heavy and spacious. Hiking is light and compact.
• Astronomy gear is extremely heavy. Mass is usually a preferred thing because it cuts down on vibration and movement.
• Rock climbing is dangerous, and I'm super accident prone. In the last two years I've had two concussions, a dozen stitches, two broken toes and a broken metatarsal. I don't remember the last time I didn't have at least a few bruises.
• The place we are going is called "B l o o d M o u n t a i n." I don't know anything about it except for that fact. Seems ominous.
• I am extremely sensitive to cold. Every time the temperature dips below 72 I start shopping for apartments in Ecuador.
• The guys want to do some filming. Like real filming. I'm going to see about inventing some gear that is intended to take some killer shots despite being in the middle of nowhere.

Enough going against me? Sure. But let's crack this nut. I've got about a month. Step one? Local rock climbing gym. Meet Aguille:

From Rocket Sparrow

I am now a fan. While they have a bit of everything I went for bouldering. First time out of the house, so they explained the V system to me and I went to town. First a V0, then V1, then a couple of V2s (these were starting to get a little harder for me), then managed two different V3s. The V4 I could only make it halfway through. Things I learned:

• Pocket grips. I don't have any of these.
• compact spaces: I'm good at this because I'm really flexable.
• I have awful technique. I make up for most things by just being really strong, so I had a habit of bailing myself out of bad situations by just hoisting myself up one handed or making a good leap and grab. This is not a sustainable solution.
• The people there are super nice. Met some great folks climbing, and they really want to see people progress.
• Climbing makes girls incredibly fit. Ladies? Oh Em Gee. If you're looking for a way to get in shape this clearly works.

The New Adventure

So I realized I kept moving on with new projects and learning new things, but not doing a lot of sharing the things I learned and did. This was always a good place for that, so I'll introduce my new adventure, bring a little up to speed, and then we all follow along as I figure stuff out. Sound good?


This adventure really starts a couple of years ago when we, on a whim, decided to build a small rock climbing (bouldering) wall in our living room. Please note this was in no way a wise idea, as the house was a rental, but we went for it anyway. You can see the success of this first step here:

From projects

It got us interested in rock climbing in general, but eventually we had to move out (and thus take down our artwork). Roll ahead a couple of years, I own my own place, 12' ceilings, and almost within days of signing the paperwork we started building what turned in to this gorgeous thing we have today:

From New rock wall 2011

It has bouldering, it has lead climbing, it can even be used for some short top rope climbing to practice belay systems and learning all the proper techniques of various climbing systems and harnesses. Most of all, it's insanely fun and is a good reason to not bother to own a TV or pay a cable bill.

That brings us up to now, where some friends have decided it's time to take it to the next level: hike out to a good bouldering spot (real life bouldering, like with boulders) and make the most of it. In addition we're looking to go camping for a few days at the spot, do some photography and filming, and for my own love of astronomy I'd like to try to do some minor astrophotography. And that brings us up to today...well except for one thing...

Turns out these aspirations are generally mutually exclusive, and as usual I'm looking to bite off more than I can chew. Carry heavy camera and astrophotography gear for a long hike, along with all the stuff for camping and survival in the deep mountains for several days? Add in rock climbing gear? Can I do it? Can I make it happen by the end of November when scheduled?

I have no idea. But I'm going to try. Also, did I mention I've never done real astrophotography outside of a pre-set-up lab before? Nor have I hiked long distances? Or camped in the cold? Or climbed anywhere besides my living room(s)?

This should be [fun/insane/horrible/suicidal/painful/freezing/impossible].

Results

Don't use this kind of vise. It's garbage, doesn't hold things well, you will break it, and it's very hard to get things to settle in flat because when you tighten it one side lifts up. I expirimented with using ATF for machine fluid. It was better than nothing, but also not the right answer.

This is part of a throttle body bracket. It is currently installed on my car:

Some other parts machined out, after all the mods but with another issue we didn't discover until after these were done. No harm though, they came out quite good:

Ketchup 2

The next weak spot was that we were relying on the motor's bearings to take thrust forces being transferred back down the ballscrew. This works up to a point (although it puts some stresses on them that will shorten their life), but once you exceed a certain amount they will push back and forth about 1/8". Most solve this by having a mounting block with thrust bearings holding the ballscrew end, and then using a spider coupler between the motor and the ballscew to sort for misalignment.

And that would probably be prefereable, but I didn't design for it and had to get creative. So above you can see one end of my motor (fortunately it has shafts on both ends) with a stop I lathed out holding a thrust bearing against the motor casing. There is another one on the other side doing the same thing, trapping the shaft in place. This was actually completely effective, and likely how I will do things in the future too. It saves on parts so long as you have some alignment adjust-ability in your motor and/or ballnut mounts.

Ketchup

And other reasons I adore the English language. I am going to try to catch up on the progress the machine has made, because a lot has happened lately. The results are that we have a darn good working machine (as you can see in the previous video) and it's only getting better as we learn.

First, once we put the spindle on some new flaws became apparent. We were getting a lot of chatter, the source of which we determined by means of high speed film (thank you modern DSLRs). The rails on Z were flexing, the whole frame was flexing, and all of that was leading to problems. This wasn't apparent with the router tool because it was taking off so little at a time (and creating a ton of heat, and taking forever).

So I replaced the Z rails with the next size up and triangulated the frame, adding a truss to the back of one mounting beaml: