Business, Linux, Space, and other random Geekery

Crash Course in Astrophotography

Jan29th
2013 Leave a Comment Written by Brian

Don’t think I’ve mentioned it on this blog before, but I’ve been a self-labeled Space Nerd for as long as I can remember.   The science and physics are fascinating, but looking at it  is absolutely beautiful as well.  My folks had given me an entry-level 4″ refractor when I was young (along with some moon and solar filters).   The first time I was able to see sunspots and craters on the moon, I was hooked.  Something about the vast distances, the sheer amount of stuff out there completely intrigues me to this day!

After a long wait I finally invested into a “lifetime” scope a few years ago.   It was Orion’s new XT12G, a monster 12″ Newtonian reflector with GoTo and tracking functionality.   It is an excellent light bucket!  On good nights here in northern California, making out the shape of the Andromeda galaxy with the naked eye isn’t all that hard to do.  I’ve enjoyed it immensely over the past couple years, but I got bit by the astrophotography (AP) bug almost immediately.   After learning some of the basic in and outs of AP, I began throwing money into savings for a new astro-imaging rig.   Earlier this month the time came to pull the trigger on a purchase,  and this is what I ended up with!

The Camera

Just about all amateur astronomers are using CCD imaging instead of film now.   It’s far more forgiving and flexible, but the cost for a good camera is steep.   The two schools of thought are using a general purpose DSLR camera attached to the telescope, or a camera specifically designed for taking space pictures.   Being I had zero prior astro-imaging experience (or really any photography for that matter), I chose to purchase a camera designed only for taking space pictures to keep things simple.

But there’s more.  The next decision is whether to use a monochrome or a color imager, the latter often being called a one-shot color or OSC.  There are some advantages in using a monochrome camera (which I can elaborate upon in a later post), though it does crank up the complexity factor a bit.   To continue my simplicity efforts I chose an OSC imager.

The camera I ended up with is the Orion Starshoot Pro 2 OSC.

The Mount

If I knew then what I know now, I probably wouldn’t have bought the XT12G.   Don’t get me wrong, it’s a great telescope–but really only for viewing.  It’s the mount.  Almost all large Newtonian reflectors use a Dobsonian-style mount in which the scope is mounted on turntable for Azimuth slew, and on a vertical mounting fork for Altitude slew.  While this keeps the mechanics of the mount very simple (and inexpensive) the mount needs to track in two separate axes to follow the sky.  Fine for viewing but not so good for photos.   Through the apparent view of the eyepiece or camera the sky will not move smoothly as it zig-zags in right angles and will rotate as the night sky revolves around the telescope.

The alternative is called a German equatorial mount, or GEM for short.  Unlike Alt-Az mounts a GEM is polar aligned, and after proper calibration only needs to move on one axis to follow the sky accurately and squarely.   The result is an image that stays planted in the optical tube with a high level of precision that Alt-Az mounts cannot muster.  Perfect for long-exposure pictures!   Being Orion has always taken care of me in the past I chose the Atlas EQ-G.

And holy cow is the Atlas EQ-G a big hunk of metal!  The mount weighs over 50 pounds without counterweights!  Yowzer.  Zero fun factor lugging to a dark sky site, but the weight and fortitude of it keeps things stable during long camera exposures.   Also, it has an autoguider port which I utilize for more accurate sky tracking.   Orion may not be the most prestigious telescope manufacturer out there, but it’s hard to deny the value quotient of their products.  The Atlas is a fine piece of equipment for the money; especially compared to the competition.

The Scope

The telescope isn’t quite the biggest concern in AP applications, oddly enough.   In fact, some really good pictures have been taken with smaller refractors, much like my first telescope.   However, since I had the camera and mount up to a certain level, I didn’t want to completely undercut them with a subpar scope.   Nor did I want spend a lot of dough (the camera and the mount combined = ouch).    Figuring I’d stick with Orion one more time, I chose the 8″ Newtonian Astrograph.   It’s specifically tailored for photography, and with extremely fast optics (f/3.9!) getting wide deep space panoramas were on the agenda.   Since I was already familiar with Newtonian-style reflector scopes and collimating them it was a natural choice.  Having a bit of familiarity in this new realm is a good thing.   It’s a pretty good buy, too!

The Extras

I also picked up a Starshoot Autoguider to use with my finder scope, even though it was out of my budget.   The Atlas EQ-G ends up tracking things amazingly well, however having that small bit of insurance that everything is staying planted in the viewfinder exactly where it’s supposed to is quite nice.   Especially when you’re spending hours and hours out in the middle of nowhere in the dark only to find out all your pictures are blurry.   In that context the extra expense didn’t seem so expensive.

Putting it all together

My brother, Ethan and me went out for first light with the scope a few weekends ago.  Unfortunately we had a half-moon to contend with, but turns out it was kind of helpful as we had no idea what we were doing and needed to plenty of adjustments in the dark.   I guess it’s an AP rite of passage to photograph the Orion Nebula.  Orion is high in the sky throughout Winter and M42 is a very bright object making it easy to capture.  Perfect noob material!

We made plenty of mistakes:  Not taking a “dark” series of images, forgetting to disable the laptop’s sleep timer and losing about 30 minutes’ worth of exposures (grr!), completely misadjusting the coma corrector lens, having the collimation a bit off (tried to do it in the field without much success), as well as not having a clue how to focus the scope with the camera installed and doing it “by eye” with the camera out.

Nonetheless, I think our first effort is nothing less than extraordinary.   I give less credit to the operators and far more credit to the exceptional performance of the equipment:  We’re hard evidence even complete dummies can take great photos!  Sure there’s some blurriness and obvious visual distortion–but this is plenty of incentive to get me back out there again.  What do you think?

M42, The Great Orion Nebula. Photographed 1/12/13 at Whiskeytown NP, California

Astrophotography, Geeky, Science    ,

Windows 8 Stream of Consciousness

Mar1st
2012 Leave a Comment Written by Brian

There is no Start menu; wait there is a Start menu. Is that a Start menu? Why are there two Internet Exploders? HOW DO I CLOSE THIS INTERNET EXPLODERS? Bubbles! Oh, that’s cool a floating clock–wait where’d it go. Fish!?

Uncategorized    , ,

A Lobbyist By Any Other Name

Jan19th
2012 Leave a Comment Written by Brian

My eyes must be fooling me.  I just saw a pro-SOPA/PIPA advertisment on television published the the Campaign For Creative America.  Is someone playing a joke?

Nope, apparently not.  The Campaign For Creative America is no other than our “friends” the big names in Hollywood and the Entertainment Industry trying to garner public support for the almost-dead House and Senate bills.   These of course  were the pieces of legislation targeted by the January 18th blackout of Wikipedia, Google, Reddit and others.

Don’t be fooled friends.  These are companies dressing in sheep’s clothing trying to rekindle any support for their dead bills.   While I’m all for earning a profit in a free market, you’re not allowed to threaten free speech and suspend due-process with unconstitutional Federal laws in order to guarantee it.

Continue to write your senators and representatives to vehemently oppose these pieces of bad legislation.

 

 

 

 

 

 

 

 

Politics, The Interweb    , ,

Careful with those BASH loops!

Dec7th
2011 Leave a Comment Written by Brian

I ran into something today that seems so very basic that I’m taken aback it hasn’t bitten me before.

For example, take this simple BASH ‘for’ loop:

for DERP in /dev/tty*; do echo ${DERP}; done

This should return a list of all the files matching /dev/tty* since BASH’s built-in file globbing expands as the list parameter of ‘for’ .   Now, try this:

[bdowney@tlfmgt1 ~]$ for DERP in /dev/heraderp*; do echo $DERP; done
/dev/heraderp*

Now the ${DERP} variable expanded to “/dev/herpaderp*”, but why?   The answer is that since /dev/herpaderp* did not naturally expand into a list of matches (because none matched) the pattern itself becomes the list parameter.   Makes sense once you understand what is happening, but seems a bit counterintuitive while programming.

I think most shell programmers would assume (myself included) the for loop would execute zero times upon no glob match.

So it would seem the correct way to handle this is by executing a subshell with a command that properly handles no-match globs, namely “ls”.   In this case, it works perfectly and as expected–but we have yet another caveat:

for DERP in $(ls /home/bdowney/*.mp3 2>/dev/null); do echo $DERP; done

If we run into a file name with a space, say something like “01 – track1.mp3″, this version of the loop will still enumerate down to three separate list items because of the spaces, namely “01″, “-”, and “track1.mp3″.    We cannot escape the subshell with double quotes, either.   So we’re back to the plain globbing again without the subshell.   So how do we resolve this?   As follows:

for DERP in /dev/tty*; do
 [[ -f ${DERP} ]] || continue
 echo $DERP
 done

Just test the loop iteration to see if it matches a file. Problem solved in all situations!

Linux, Scripting, software    , , ,

Old School Made New: Tradewars 2002

Nov15th
2011 Leave a Comment Written by Brian

Many moons ago I ran a somewhat successful bulletin board system (BBS) called Communication Breakdown.  You remember BBS’s right?

For all you newbies out there, BBS’s were the precursor to today’s Internet.   People ran computers out of their homes hooked up to their telephone lines, and people would call each other using slow telephone modems to post on message boards, download and upload files, and play games.   Many of the good friendships I still have today were made on BBSes in the 1990′s.   That was the key difference versus the Internet today:  Because you had to use your phone and could easily rack up a huge phone bill, generally you called other boards that were local.   Naturally meet ups would often occur and friends were made.

But I’m getting off-topic.   One of the bright spots of calling and running boards were things called “door games“.   These were simple, text-based (modems, remember!) games that often involved interactions with other people on the same board, playing the same game.

Remember, in the early-to-mid 1990s MMO games like World of Warcraft and Eve were not even possible.   Yet, on a BBS people could play against each other on-line  before any of us even knew what TCP/IP or a web browser was.  Back then, this was pretty mind-blowing stuff.

One of the bright spots of the era was a game called TradeWars 2002.    In every conceivable way, this is the great-grandfather to today’s Eve Online.    Trading for profit, corporations, alien encounters and building up ships:  Tradewars had it all years before Eve was even an idea.    Better yet, it was free and you could play it as much as you wanted (unless you ran out of turns for the day!)

A casual discussion came up in the office regarding old BBS stuff, and I was pleasantly surprised to find out that Tradewars 2002 is still around.    Not only is it still around, it’s undergoing active development and has a dedicated following!    Of course I had to set it up and start playing it with a couple of my co-workers.    It’s every bit as fun as I remember, too.

Give it a shot!   Telnet to tradewars.thelinuxfix.com and start playing.  We won’t blow you up… too much.    You’ll need a terminal (like PuTTY) that can do proper ANSI emulation.  I bet “ANSI” is another term you probably haven’t heard in a good 10 years, either!

TW2002

The TW2002 splash screen

Cool, Geeky, Other Stuff    , , , ,
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