Linear Regression

Hi there, Long time no see, sorry I have been rather quite taken with various business ventures and so I have not been working on my projects as much as I should have. As I have had a lot of downtime recently as the semester winds down I have been taking my free time at work to learn some celestial mechanics.

The notes I am using are great and so I will link to them here.  It starts off with a primer on numerical methods, one of the things he asks you to do is create a program which will compute the  least squares solution to an overdetermined system, then apply that program to create a least squares fit to a set of data. This was the method Gauss used to create tables of ephermrides for asteroids, but it presents and interesting set of computational problems,

1) how does one represent a matrix in memory
2) how does one solve a system of linear equations in a finite number of steps
3) how does one then use that solution as a polynomial to evaluate a coefficent of determination.

This has occupied my time on and off for the past couple of weeks. It suffices to say I learned a lot about representing mathematical objects in a computer. Polynomials are really quite facinating actually. For example it is possible to compute a polynomial at any unknown value in Ω(n) time where n is the degree of the polynomial.

Another interesting question is how does one test a linear least squares code once its been written. The answers are found in my github repository. Here I will only present my results:

The test data and fit

Polynomial model: 
Degree: 1
Coefficients:
a_1: 7.939715
a_0: 1438.362123
r: 0.997310
r²: 0.994628

Post observing report 12/23/2014

Hi all,

I thought last night was a lost night. First I forgot all of the manuals for my equipment at home, then it seemed that the telescope would not point, ever. Here is a summary of what I learned. 

Balance is crucial

The mount would not pont properly due to a wild imbalance in the declination axis, this resulted from balancing the tube with the camera attached but without the finder attached. The resulting imbalance caused the telescope to swing wildly when slewing in the declination direction. 

Need more power, Captain!

The night ended as a result of the Canon SL1 loosing power, this was after I had spent two hours charging it to make sure it was fully charged. The obvious solution is to power the Canon from the 12v SLA AGM battery which is not at all discharged even after running both the telescope and laptop from the begining of the night to when we packed it in. 

The best eyepiece is a Canon Camera

I cannot over emphasise how impressed with the Back Yard EOS software I am. I was able to get closer to good polar alignment than I ever have before using the camera to drift align the telescope. The thing is that now even if I wanted to do something with another imager, I think I would use the cannon first to align everything. 

As I have said in the past, many times, murphy's law goes double in Astronomy. At various times, the software for pointing the telescope, EQMOD, would not take input from a gamepad, or would claim to be pointing the wrong direction, these issues in and of themselves were not fatal, and that is progress. 

The final piece of good news from the night was that we were able to catch decent images of Albireo, and while there is significant coma at the edge of the field the images of the double star itself are still impressive. But the best image of the lot is one with a meteor in it:

Finally I have revamped the astrophotography page for the blog.

The interminable list of things to do.

Hi All,

Now that the semester is nearly over, I have a couple of announcements. First, I am not going to be returning to my Mathematics PhD program at ASU. For all of my friends still working toward their piled higher and deeper degree, I wish you the best of luck, and who knows I may drop by from time to time when I am tutoring on campus.

Now that that announcement is out of the way. I am currently working on a project with my little (read: younger) brother which may or may not result in more money coming my way. In any case, I am now as busy as I have ever been working on various projects.

OpenAIP is still alive and well though the code is still in rough shape, it probably still compiles though their is a lot of learning I need to do before I return too it. Unfortunately, my coding time has been hijacked by the project with my brother.

The telescope is still in boxes, for the most part I have not had time during the busy semester to use it and now that my time is clearing up the weather is not cooperating. I am still looking to get the equipment together I need to go camping, which should happen some time early next year.

I am still hoping to work on a focuser for my telescope, using my Arduino. I don't think I posted the videos from dipping my toes into Arduino programming so here they are:

Hopefully over the break I will be getting some more pieces, specifically a stepper motor, a driver and some optoisolators. If I can get that working I will post it. Also I have decided to start a Go Fund Me page because I am shameless and all of my projects seem to be out of my price range.

The next thing

So first light was a success, I was able to get a pretty good polar alignment and take some out of focus star images to run through WinRodder. For perspective here is a 1second black and white image of a star field from first light.

The bright star at the bottom of the frame is Vega.

I know what you're asking why would you want to take an image of an out of focus star. Well WinRoddier is software which attempts to reconstruct the wavefront of light coming through the telescope optics from Vega, the result is a reconstruction of the optical aberrations, or optical imperfections, of the mirror. In short this software will tell you if your optics are good, bad or mediocre.

Unfortunately I took images in TIFF format when I needed them in FITS format, the problem is that the software I used to operate the camera saves TIFF images in RBG (Red, Blue, Green) channel format, this results in the exact same data being written into all three channels.  Which lead me to have to go through a round of extracting the color channel data and then running it through WinRoddier.

Only to find that my aberrations were huge, not necessarily because the optics that were sent to me are bad but because I forgot about the first element in my optical system, the sky itself. Air pockets of different density refract light differently, and thus as you take an image the first lenses that light pass through are these air pockets in the sky, now from the above image I was able to measure the seeing, or the ammout of distortion caused by the atmosphere, its 2.68 arcseconds, which is not aweful (>5 arcseconds) but it sure as heck isn't good. (<1.5 arcseconds) The humidity on Monday night was high which probably contributed to the seeing. So now I need an artificial star to test my optics in doors.

Finally the software that I used with my camera is both old, and poorly designed, so I have now taken to working on a piece of software to replace it. But since have always claimed I wanted to write a Open Astronomical Image Processing software solution, now is as good a time as any to start. The code can be found at GitHub (in the Warp_Core1 directory) if anyone is interested in my next steps. It currently uses Visual Studio 2013 to compile.  

First Light

So it looks like I will be setting up my scope for the first time tomorrow night. I have added a section to the blog called Observing Plans. There is a plan for tomorrow night. There are a couple of reasons this process has taken a week longer than I had wanted it too. First, their was the weather which is annoying during the monsoon season here in Arizona.

The second is much more insidious, I was trying to find an open location which I could use as an observing site, however most parks in urban areas close earlier than one would like. So I had to call around to several parks departments, no one was willing to grant me a permit, I also called one golf course and the manager of operation literally could not get me off the phone fast enough.  It seems that we as a society are so afraid of our own shadow that a person cannot engage in a simple hobby without everyone losing the minds. 

Some would say that you should just set up your scope and not ask, well unfortunately we don't live in a perfect society so I would much rather play by the rules than chat with the police. The good news is Wagoner park is open until Midnight, sunset is ~7:30pm which means I should get a good 4 and 1/2 hours of work in before the night is out. 

Updates

Hi all,

I feel as if I owe the world an update, I know that sounds weird since I am under no obligation to write this blog regularlly. Anyways a few things have happened since my last post (in May) my car burnt to a cinder. So now I have my expedition vehicle  a 2014 Jeep Wrangler unlimited, the good news is this will eventually serve all my purposes, including going to Death Valley and Baja, however it will not be built out until I can pay it off, which is 72 months away. Until then we will have to plan to go to more hospitable locations.

The good news is that I have not been busy which means that I am building out my capacity to do astrophotography. Behold my latest creation:

This is the F/3.9 8" newt on a Orion Atlas EQ-G mount. Sitting in my brothers bedroom. It is not fully operational yet. I have done one iteration of balancing it and I have done a quick look at the colimation along with a first pass at collimating it:

The process is slow, I have been building some cables one which will allow me to control the mount directly via a USB interface using EQMOD. The other which is a serial release cable for my Canon SL1 camera. All in all progress is moving forward and we should at this rate be on track for Alamo Lake in Fall. (fingers crossed)

Busy

Hi Folks,

Its been awhile but mostly what I have been doing is working. If your a facebook friend you already know that I am below 300lbs. A lot has changed in these past few months, now that I have shrunk I have much more energy! This has lead to me becoming a Doer, the result is that I am currently working with a new laptop.

Now we are moving into the Plan. I am ordering a new telescope optical tube tomorrow, and updating my pinboard. The next month will be spent trying to secure the GEM for my mount. Along with birthday money I will hopefully have the telescope and mount in late June, then the fun begins.

My plan is to start in my back yard, setting up and tearing down the scope, using eyepieces to split doubles and star testing. I have found my old DSI Pro II not only works, but works in linux as well. I hope to turn it into a guide camera on my setup.

Once the mount and Telescope have been setup I am going to try and figure out how to start my camping setups, more than likely I am going to purchase a tent, after I have some of the big ticket astro imaging items done. I plan on doing a trip to Mt.Lemmon or something of the like in August, but we will have to see. In the fall though expedition one may go off.

In the mean time Stay tuned to the pinboard as Items are purchased they will go off the list.

A couple of more items, this saturday 5/04/2014 I would like to get a group together to talk about projects they are working on. I hope to make it an ongoing thing, which may become a club.

Also I have started a wiki, Exemplar Astronomiae its latin for a book of astronomy which is meant to be copied. I hope to put up tidbits of knowledge as well as some experiments people can do with telescopes from 5-42inches. Hopefully the experiments will be detailed enough that people can repeat them. There is a section for equipment as well, with instructions for various calibration and testing strategies. My hope is that others will eventually contribute but we will see.

Next Steps

So I am almost to the point of purchasing my laptop. My next purchase is going to be the OTA for my next telescope. Why the OTA first, because its on back order until June, so I need to order it now and get it while the getting is good. Next is the mount, followed by my camera modification. Then comes the fun part, each of the little individual components necissary to make my telescope work properly.

These range for the coma corrector to the laser collimator to reticle eyepieces to autoguiding setups. Not to mention I have to go to a wedding in August. Hopefully we are on track to do our first expedition next October, but we will have to see. I will post pics of my laptop when it comes in hopefully in a couple of weeks.

In the mean time I have created a website for the two aspects of my business, tutoring and computer repairs. It can be found at twedgec.com.

Running Behind

So the plan is proceeding, sort of. Right now I am saving up some money but unfortunately I am not prepping to buy a scope. The first thing I need to get is a new laptop. My current beast of burden has served me well, but its been worked too hard for too long. As a result my acquisitions are behind. My initial goal was to purchase the telescope and mount first followed by some camping gear so that I would be ready for the Grand Canyon Star party, now it looks like nothing will be happening until next fall.

If you are interested in what I am planning for a new laptop its a rather funny story, I am planning on getting a bare-bones kit and building it up myself. You can get them at rjtech.com with some $10 spudgers you can make yourself a laptop, it will be pretty heavy, however I am not noticing the girth of my old laptop as much now that I am getting healthier. I am hoping to order the laptop by mid April, once that is done I will hopefully have enough by mid-May to buy my scope, which may take a few months to get here.

Be the Change

The plan is still on, I am attempting to ramp up my business in order to get to the point where I can purchase everything that I will need. But I am restless, the problem is that I have a need to tinker. To this end I have bought an Aurduino Uno board as a platform for building a Temperature compensating focuser. The focuser software will run under Linux Mint.

The thing that has always bothered me about Amateur astronomy is that the tools we need for our hobby cost so much. Software which should not be expensive is either hundreds or thousands of dollars. This needs to change, which is why I started OpenAIP. However this project will never get finished as long as all of the tools needed to go around it are gestating. The good news is that there are good hardware platforms on Windows and Linux, ASCOM and INDI respectively. The next step is to build the tools on top of these platforms for image processing.

GIMP should do the job of Photoshop, and to a certain extent it does.  But we have no equivalent for Maxim DL (hence OpenAIP). My personal opinion is that a version of linux dedicated to astronomy should exist. One where you can simply boot your computer up and try it or install it and make it work for you. But this is a goal far off in the future, for now I will start with my focuser and eventually get back to OpenAIP.

Look forward to tutorials for installing INDI on Linux Mint/Ubuntu.

Ed. 
Of course after I wrote this Cinnamon inexplicably crashed so hard I had to re-image the machine overnight.

Beginnings

Hi all,

I am one month out (from surgery) as of today. The funny thing is that things have started to happen. First there was this blog, until now it was a way to keep all of you who were interested updated about my journey and plans and now it has grown to actually planning for expeditions. There are also pages for photography and astrophotography which will hopefully be coming soon.

This week I also spent some time on the weekend playing with some old equipment seeing what if anything still worked. It turns out quite a bit. The interesting thing is that I now have the beginnings of some gear, an old set of Pössil eyepieces (the entire Meade 4000 series) which seem to be in mint condition. On top of that my Meade DSI Pro II mono seems to work, in Windows 8! I was also able to find a working GPS receiver with a USB output.

So it looks like I am on my way with my next imaging setup, but I have learned that the main OTA that I want is going to go up in price as of next year, and so I am wondering if with these next couple of Paychecks I should purchase it. That would be the start of my imaging setup however the danger in that is that I would end up with something that I could not easily test until I have a mound to go look at (and take pictures of?) unfocused stars.

Things will be getting interesting over the next few weeks folks. If you know anyone with $85 an hour who needs computer help let me know. I am also tutoring for $35 if you know anyone who needs it.

P.S. Something that will definitely be happening with my next couple of paychecks will be me fabing a cable for EQMOD.

Additions to the Blog

The expedition preparation page now has some prose on there, along with links to some pin boards which might be of interest to people planning to go on expeditions.

Also I have added new recommendations for first scopes, some more reasonable than others. All in all I added reasonable quality GOTO and non-GOTO scopes for the most part 8" is too large for a non-Dobsonian telescope. I personally think that 6" is pushing it, as far as usability is concerned.

ACA and Me (Along with blog updates)

Hi all,

So here it is, part of the reason for my travails at the beginning of the semester was an attempt to keep my health insurance. Now that the Affordable Care Act exchanges are up I have decided to buy health insurance from Blue Cross, Blue Shield of Arizona.  The result being that I hope to no longer be afraid of loosing my job or my status as a student for fear that I will loose my health insurance.

This is a tremendous burden lifted off of me. Now its time to concentrate on moving forward. I have gone back to work which should allow me to begin saving money shortly, right now I am eating less than ten dollars worth of food a day. The next step is to increase my income so I can begin making purchases to go on expeditions. This has led to a couple of site redesigns, the tabs at the top will show my progress as I loose weight. I have even begun walking my dog further when my hands are not frostbitten.

The good news is that my weight is coming down nicely, also at the top you will find links to pinboards as well as expedition planing ideas and guides. Those will be under construction as time goes on. Right now its looking like I will be ready for the Grand Canyon Star Party next fall if I can just put together enough money for the scope and the camping gear.

Speaking of the scope, I have decided to re-purpose my DSI II mono as a guide camera since I don't really feel like paying $300 for one. I have also purchased Photoshop since it was on sale for 50% off, which is a great deal that is still going on, hence if you want Photoshop CC I suggest you get on it right now.

Size doesn't matter

Hi all,

I had my two week post op appointment, and guess what? I am doing so well they advanced my diet, no more full liquids now I am on to mushy proteins!

Now I need to begin by discussing a sensitive subject.

Ladies and Gentlemen I need to talk to you about the sizes of your equatorial
mounts. Now I just went back and corrected some mistakes in my rant about aperture when I came across this monstrosity:

This is the Skywatcher EQ8, and there is some excitement about it, even talk that it will challenge the big boys, i.e. the Paramount ME and the Astrophysics AP1200. To this I say, so what? This thing ways about 110lbs, which means that you will take it out once a year if at all, the same thing goes for the Paramount and the AP1200. This is yet another symptom of the bigger is better mentality, and it is highly correlated with aperture fever. 

If you want a beefy equitorial mount you are sport for choice from the CGE Pro to the LX 850 to the Losmandy HGM Titan, but the question you have to ask is, is a 100lb mount really "portable." Just because it mounts to a tripod does not mean that you can lug it around as much as you want. The only way these mounts are truly useful is if you put them in a dome near your home. 

Its an insidious trend I have noticed, taking ridiculously massive mounts, putting them on tripods and calling them "portable." The EQ8 even has handles on the mount head. If you really want to do astrophotography get yourself a sturdy workhorse like them mount I am going to get:

And yes I changed my mind again, the Gemini II system scares the shit out of me, I think it might be too complex for its own good. 

Order of Operations

Hi all,

Now that I am a week into my liquid diet, I think its time to admit that this is happening. If you want tips for surviving a liquid diet I would be more than happy to help. However, its time to talk about The plan again. So the goal is to be able to go to the Grand Canyon Star Party as our first expedition this will happen next summer assuming all goes well. However I need a road map for my acquisitions. Things have been made more complicated by my insistence on a Losmadny G11 for my mount.

It suffices to say that the first purchases need to be the laptop and the telescope, these will be the biggest expenses next to the purchase of a new SUV at some point in the next year, probably next fall. But we can break it down even further, the main problem with building a telescope from scratch is that you will inevitably mess things up. You can have all the wishlists and planning that you want but your going to inevitably meet with the fact that Murphy's law goes double in Astronomy.

Your main enemy is the complexity of open loop tracking systems. Everyone solves this with a guide camera, however there is something much more insidious. I have often said I will never buy a used telescope mount and here is why,

This is as close to a precision mechanical instrument as you can get in our hobby, it requires knowledge of mechanical and electrical repair and it is very sensitive to the weight that you put on it. There is no way you can just flip a switch and let it do its work. It has to be coaxed and finessed into doing its job. You cannot loose patients with it, you cannot try to reason with it. You can only be patient and work with it. If you try to take it out of the box put weight on it and get it to track and point, you are probably going to destroy it. 

This is the problem with mounts, they are a lot like cars, and this leads people to treat them like cars. That is to say that for the most part people treat there cars like shit. They assume that its going to work and when it does not they get frustrated and/or irate, when a car is a mechanical object and hence it must be maintained and taken care of, it does not need near the coaxing as an astronomical mount but the point is that you should not just abuse it and then expect me to purchase it. 

So I am going to buy the mount first, take my time assembling it, powering it on learning to balances it, getting to know its nooks and crannies and when I am done I will buy a telescope and put it on the mount, but not before I have taken the time to understand this object. After the mount then I will probably by a Camera, then the telescope and guide scope package. The laptop will also go in there somewhere since it is just a very useful object to have around. And once that is all acquired there will be test runs in my back yard then maybe in Tucson. The reason not to just get into my truck with a new scope and take it to a dark site is simple, it won't work. The scope won't work, the trip will probably be a disaster. 

The Software Problem.

A few posts ago I stated my intention to purchase a MacBook air. The good news is that the first facets of "The Plan" are months away from being implemented hence the plan is still in flux. The MacBook is probably the nicest single piece of hardware currently available, however MacOS X is  not suitable for amateur astronomy in my opinion. Several Apple fanboi's heads just exploded, but hear me out. When you have a hammer everything looks like a nail.

The problem is that the primary purpose of my next laptop will be the control of the telescope and focuser for acquisition of images. While there are plenty of applications that work with OSX which will do data acquisition there are serious gaps in the hardware support. The drivers for these objects simply do not exist for OSX.

Now the gap between OSX and Windows is nothing compared to the gap between OSX and Linux. People simply do not make decent acquisition programs for Linux. Now the thing about the hammer and nail is that since OSX is a UNIX  you might just say, "Aaron your a competent programmer, why don't you just write the drivers." To which my answer would be "F$#@ YOU!" because writing drivers for hardware you don't manufacture yourself is about the most arduous task one can set oneself.

The root of the problem is the fact that this hobby is small and populated mainly by a generation of people for whom modern digital technology didn't exist. The result is that most of them are windows users as a result of some anti-competitive shenanigans in the 90's.  Hence everyone who makes hardware to interface instruments to computers makes drivers for windows. I would argue that any off the shelf components are best plugged into a windows computer, since Murphy's Law goes double for Astronomy.

The solution of course is to make interfaces to mobile devices, tablets and the like for controlling instruments at the observing site, Bluetooth is more than capable of wirelessly controlling a telescope. However unless wireless USB matures and becomes a standard we would be stuck with Wi-Fi for carying image data. This is a problem I am interested in working on since wires and darkness tend to be a witches brew for ruining expensive equipment. Any thoughts readers?

More on First Scopes

Hi all I have been thinking about first scopes for the past couple of days. I have put together this pin-board to refer people too in the future. The problem with first scopes is complicated so I think it would be best to put all of my thoughts down on paper. (so to speak)

It is a cliche at this point to point out that there are a bunch of really bad options for your first scope, but these generally fall into the category of a small refractor (50-90mm in aperture), it could be on an equatorial mount or not, it could also have a clock drive. None of the bells and whistles matter, whatever you do do not buy an instrument for visual use that is in this aperture range. The problem has to do with the fact that while they are light and portable you cannot see anything with them. Usually they have terrible quality optics but mostly the problem is that the sky will swamp out anything other than the brightest of objects in the city.

Now your going to ask me why I don't have any Catadioptric Telescopes on this list, the reason is that there focal lengths are so long, but mostly it has to do with the way they are mounted. No initiate amateur should ever deal with an equatorial mount, the set up is too complicated resulting in whole nights wasted trying to make things work. The only other option is a fork mount and there we have a whole other set of problems. Since forks grow with the aperture of the telescope you are restricted to single arm fork mounted telescopes 8" in size if you are going to use it more than once or twice. This is a hard truth to understand but the fork is both heavy and weirdly shaped resulting in it being uncomfortable to carry. This means that you won't use your telescope. Don't believe me? Go to ebay (or Astromart) and search for the phrase "only used once" or "only used once or twice" when looking for a telescope.

While we are on the subject, you may think that you will get a deal buying second hand telescope. This is a terrible idea for the following reason, you don't know who owned it. Telescopes are sensitive instruments meaning that if they are misused or mishandled in any way they may require costly repairs or be utterly unusable. For the most part GOTO scopes will have issues with there motors and gears, Newtonian telescopes will require collimation. These are issues you do not want to have to deal with without a stout warranty and some guidance.

The truth is that the only way your going to get into the hobby and staying in it is to have a telescope that performs well visually while at the same time being portable enough to take into your back yard at night. This leads us to the Dobsonian telescope. Basically you take a Newtonian telescope put some castors on the sides of it and put it on a rotating platform and you have an altitude-azimuth telescope. Add optical encoders to each axis and a computer and you have something that can be used to tour the sky with relative ease.

For the impatient this is the best option in less than an hour you will have your telescope setup and be exploring the sky with 6" or 8" of clear aperture. You won't track objects but you will be able to find them. If your a patient person then I would suggest something without the computer, since it will enable you to learn the sky the hard way, finding objects by star hopping.

I would not recommend GOTO telescopes for your first scope. Why? Because they are pieces of technology, slightly anachronistic since they have a digital computer, only in the most rudimentary sense. Usually GOTO telescopes end up being unusable, leading to a great deal of frustration with no objects being viewed through the scope.

Now the last and most important tip is this, Amateur Astronomy is a frustrating hobby no matter how you do it. There are very few shortcuts that don't end up being headaches at some point. The point I am trying to make is that perseverance is a necessary and sufficient condition no matter which road you chose to make astronomy your hobby.

Signal and noise

Hi all, I owe you a blog post but I have actually been busy. The surgery stuff is progressing I still don't have a surgery date and I am still massively frustrated with the disaster we call an insurance industry in this country. However I am not going to complain about that I am instead going to complain about something else.

When you don't have a telescope for astrophotography you spend most of your time researching which telescope to buy. Such things occur naturally with hobbies, since the goal is to chase the dragon for the most part. Its strange the first money out the door is going to be spent on a car, an old Subaru Legacy 5 speed (hopefully) then comes the telescope, then comes the software for the telescope then comes the computer upgrades.

My point is that planning is the only thing I can do and part of planing is research. The problem with research is that because the community is small there is a lot of superstition being perpetrated as fact. The best example of this I have come across is focusing.  Astrophotography is part art part science. The art is in the photographs, the science is in the planning on how to get to the photographs. When it comes to actually taking picture I anticipate trouble in two actions, the first is in polar aligning the mount, this must be done any time you move the telescope to a new location or break it down and set it up. The problem with polar alignment is that it is complicated and you want to do it well, this may mean taking a couple of hours to polar align your mount. The methods for polar alignment are not all that controversial.

However the second place I think I will have issues (and by I, I mean all astrophotographers) is focusing the telescope and keeping it focused. There is a great deal of information about focusing some of it might not be all that useful. The problem comes in that for the most part telescopes bend light so it comes to a focus, how they do this is very much dependent on the length that the light has to travel. The problem is that focusing needs to be exact, the goal is to get stars as small as possible on the imaging medium. You can do this crudely by hand, but most go to some sort of mechanical help for this, then there is the problem on thermal expansion. See most objects length changes with temperature, the result is that your focus (the place where your stars are smallest) moves as the temperature changes. This also means that the spacing of your lenses changes as temperature of the cell holding them does.

This could result in a lot of painful problems, not the least of which is people telling you that you should not get a carbon fiber telescope tube for a refractor since the lens cell is designed to compensate for changes due to thermal expansion. This is however a third order affect, the expense of getting a carbon fiber optical tube is a first order effect on your wallet. The interesting thing is that you should probably refocus periodically anyway because your never going to be sure where the best focus is.

Let me explain, when I was talking with my friend and mentor about this issue he asked me this question, "Where are these people going to get 0.5" seeing?" In order to see the effect of having a carbon fiber tube you would have to have really nice skies, since the is not a uniform object, its temperature and speed vary we get tiny lenses forming in the atmosphere as the local air changes, this is called seeing. Seeing acts like little lenses dancing in front of your objective, resulting in stars twinkling. More than that it is something you can measure with your camera, since even when focused the seeing smears out stars on your image plane.

Seeing effects your images much more than any choice of optical tube material. So don't worry about what your optical tube is made of unless your going to launch it into space. This has also made me leery of talk of a critical focus zone on a telescope, maybe a reader can explain why between actual thermal expansion and seeing I should worry about my focuser moving a few microns?

Some of the Nitty Gritty of Expeditions (With first scope advice!)

Hi all, Its been awhile. Sorry I  haven't posted, but its hard to think of pithy things to say when your on your back in a CT scanner. Anyway I have had substantial interest in the Astrophotography Expeditions so I think its a good time to talk about some details. (Subject to change since the first expedition is over a year away.)

 The idea is that as long as your willing to bring your own food and gear for you and yours you are welcome. We should have multiple vehicles since I can only carry one person other than myself. The idea is that there will be multiple tents, mine will be for gear and maybe 2-3 people other than myself. We will get together before hand to make sure there is tent space for everyone. Individuals will be responsible for there own sleeping bags and pillows. Now since there will be astrophotography it is going to be natural to ask the question of what other are supposed to do at night.

 I would encourage people who are bringing there own vehicle to bring a scope. This leads me to a question I get asked a lot, which is basically what kind of telescope should I buy. Since we will be under dark skies it will be an opportune time to explore the night sky. The scope I think everyone should start of with is a Dobsonian. My personal recommendation is to go to Orion Telescopes and Binoculars for your first dob. I started out on a 6" and had a blast under suburban skies, so it I would say a 6" Dob would be the low end. Now if your willing to save a bit of money I would actually recommend the XX12i Truss tube, as it will be easy to transport and give you better views at the eyepiece. The computer will give you instant gratification, by pointing you at objects and giving you tours of the night sky, but to push yourself  and get better at astronomy you need to try star hopping to your target. Finally if push comes to shove a good pair of 7x50 binoculars can give you great views without the hassle or the expense of a scope.

If you have some experience with using a telescope and your poison is taking photos of the stars and planets, well I don't really know what to tell you since I cannot recommend my setup to anyone yet. I mean stay tuned for test reports but until I actually have the scope and camera and try it in my backyard or in a field, I cannot say for certain its the right way to go. If your a novice just starting off I would go with the Orion Sirius 80 which is sort of the standard telescope to start out with for astrophotography. As for a camera, I would start of with an unmodified Canon EOS. (t3 or t3i) This will give you a taste for astrophotography.

Now you may be saying, Aaron none of these scopes are what you would buy, and that is correct. However I am not a novice, I am a journeyman. (or at least I tell myself that) I am configuring a modular system for specific targets. When the time comes you may want to do the same, these suggestions are for people beginning there journey.

I would like to reiterate that I do not recommend people jump right into astrophotography, its hard enough when you have a vague notion of what to do, its is impossible if you do not know if you have the target you are interested in in the Field of View of your scope.

The elusive block 3

Hi all,

In case you were wondering what on earth was going on with my previous blog post. There was a section about a Block 3 version of my astrophotography setup. This was an insanely expensive TEC refractor paired to a super expensive Paramount MX. ( I am fighting not to use the adjective astronomical anywhere on this blog.) Instead of a redo of my mount and telescope in Block 3 I have decided to just buy an APO in Block 1. Block 3 initially disappeared  but now I have added a new upgrade, to a 35mm Starlight Express camera with narrowband and  LRBG filters. This may be years down the road so stay tuned.