Wednesday, December 31, 2008

The Moon and Venus

Happy New Year's Eve everyone!

Tonight the Moon and Venus put on quite a show right after sunset. Venus was very bright and dangling right below the lovely crescent moon. It was extremely windy and cold, but I went outside with my Canon 30D and the Tamron 28-200mm zoom to grab this shot.


Tuesday, December 30, 2008

New Ride!

I've also been preoccupied with my new vehicle which I picked up off of Craigslist in Washington, DC. It's an electric scooter called the "eGo Cycle II Classic". It's a 24V 35AH scooter with a 2HP motor. It can go about 25mph and has a range of 15-20 miles on flat terrain. What a fun ride! It has some minor issues, the brushes on the motor need to be replaced and the back tire has a bad case of being out-of-round, but those are easy things to replace...

Ordered a Dewalt Jigsaw

After much deliberation and mulling in my head on how to make this cut, I've finally decided to not do it by hand and ordered a Dewalt DW318K orbital jigsaw. This should arrive in the next few days and allow me to make the cut easily!


Wednesday, December 17, 2008

Full Moon at Perigee 12-12-08 Take II

I had a sneaking suspicion that something was wrong with the first moon image I put up. The moon didn't seem very round! Taking a closer look at it, I can see that my stitching software, Smoky City Design's Panorama Factory had misplaced the merge points and had actually duplicated the upper middle part of the image. You can see the duplicated if you look carefully. You can see two columns of veeeery similar craters! I'm leaving the blog entry up so that everyone can see it. Here is an updated version of that image with a little less sharpening and better merging.

Antonin Rukl's Atlas of the Moon!

I've heard wonderful things about this atlas. It's legendary in it's cataloging of all of the craters and mare on the moon. I just picked up a pristine copy on Astromart and look forward to getting it soon. 

Monday, December 15, 2008

Full Moon at Perigee 12-12-08

Early in the evening, I saw the full moon rising above the horizon and it was gorgeous. I was very disappointed to see the clouds roll in shortly after that and kind of gave up hope. At around 10:30 PM, I looked outside and saw that the moon was nearly at zenith and the skies were perfectly clear. I grabbed the Coulter and headed outside. This is the result. It's my best full moon shot so far. I'm very happy with the result. I hope to be able to get even more detail when I get the Dob Driver II installed and working.

Friday, December 12, 2008

The Moon is Full and at Perigee Tonight!

Tonight is a rare combination of two events. The moon is full and at perigee tonight. It's a bit cloudy right now, but I'm planning on being out there taking photos tonight!

Ambrose Liao

Wednesday, December 10, 2008

A Belated Introduction

I have just now realized that I haven't introduced myself or my astronomy hobby. Here goes:

I started getting interested in telescopes when my wife and I went on a vacation with her spotting scope; an old Kowa TSN-2 76mm model. It has pretty good views and I really enjoyed it. This interest went viral when I saw what could be done with digiscoping with a point and shoot digital camera. 

I had a Canon Powershot G7 at the time and was challenged by how to get it to work with the Kowa. My first attempts were abysmal failures. The 6x zoom of the G7 just doesn't work well with the 20-60x zoom eyepiece of the Kowa. Since I've always been one to uhm, not opt for the most expensive option out there, I decided to try and make the two work together by hook or by crook but certainly not by throwing money at it! The major problem was the tremendous amount of vignetting that was happening with the scope/eyepiece/camera combination.

After much reading and experimenting, I found that the Kowa zoom eyepiece was at least partially to blame. The eye relief available from it was very short and just not compatible with the G7's long eye relief requirements. I then tried putting my old Nikon SLR's 50mm f1.4 lens up to the Kowa and the G7 and that seemed to work fairly well. I then bought some step down adapters from to see if I could match the lens to the scope. I measured the threads on the Kowa and found them to be around 43mm. I bought a couple of rings in order to match the 58mm of the Nikon to the 43mm of the Kowa and voila, it worked!

I was able to take good quality moon photos! 

There are obvious problems, general softness and fairly bad chromatic aberration (green and purple fringing), however, I was fairly happy with the results. 

After hanging out at the digiscoping birds Yahoo group, 

I found many spectacular examples of digiscoping that were truly inspiring. Many of the experts there used Swarovski, Leica, and Kowa Prominar spotting scopes with their point and shoot cameras. The problem is that these scopes typically sell for over $2,000 with no eyepiece!

I thought for a moment and realized that their expensive spotting scopes were really very high quality telescopes with erect image prisms in them to right the images. I then realized that there were many high quality scopes and many high quality correct image diagonals available at significantly lower prices.

I then searched for a good high quality small refractor. That lead me to which I highly recommend and bought my first telescope, an Astrotech AT66ED APO. Along with the scope was a 2" Astrotech dielectric diagonal and a Stellarvue multi-reticle red dot finder.

At about the same time, I picked up a Universal Astronomics Unistar Light Basic mount and UA surveyor's tripod. The whole setup (scope, diagonal, mount, tripod) was only $475; about the cost of an eyepiece for the high-end spotting scopes!

After about 6 months with the AT66ED APO, I was perusing my local for telescopes and came upon the 13.1" Coulter Odyssey 1 Dobsonian. I was the first to respond and by pure luck, the owner was about 1.5 miles from my home. I rushed over there after dinner and grabbed the Coulter (which was in excellent shape), two Televue Plossl eyepieces (32mm and 7.4mm), a Televue 2.5x Barlow, and a Telrad finder for $175!

Thus my adventure in upgrading and modifying the Coulter began! You now know most of the rest of the story. I've got big plans for the Coulter, including a truss Dob in the future from a plan that I have in my head right now

As for why I'm into Lunar Photography... I would love to be able to digiscope birds, however, with two young girls and a busy work life, I am not able (very often) to go birding with my scope so have put that on the back burner and am focusing on moon photography since I can do that when the girls are asleep!

More later!

Ambrose Liao

Monday, December 8, 2008

Pearl Harbor Day Moon 12-7-08

I didn't get a chance to do the big cut this past weekend, but I did get outside with Clifford (my big red Dob) and took this shot. It's a stack of 10 images from my Canon 30D mated to the Coulter.

It was very windy and cold out there. 22 degrees and 10-15mph winds! I'm amazed this turned out at all! Copernicus and Tycho really show up very nicely and Montes Jura lurks in the shadows.

Ambrose Liao

Friday, December 5, 2008

Prepping for the Big Cut!

I've marked (actually scratched) the line I plan on cutting on the rocker box of the Coulter. It looks gigantic and kind of scary. I don't have a workable power jig saw to do this job so I may have to improvise with a hand saw doing multiple cuts. The good news is that the Coutler rocker box is built like a tank so sawing it should be easily done by putting it on it's side. I hope to be able to do the work this weekend.

Ambrose Liao

Thursday, December 4, 2008

The First Cut is the Deepest!

I measured and marked out the central area for the azimuth motor and I took a hand saw to the rocker and cut out the notch for the Tech 2000 Dob Driver II's Hurst stepper motor and gear assembly.

I then test fit the motor in the slot. It seems to fit well. I may need to notch out the slot a bit so that the motor sits flush with the board rather than proud of it. I want to be sure that the diamond patterned wheel makes solid and balanced contact with the base board. There are two roller assemblies which need to be mounted underneath the rocker and replace the Teflon pads that are there now.

This is the view of the stepper motor from the front of the rocker box. I may need to paint the stainless steel plate to help make it blend in more with the rocker box.

Next up is to cut out the large circular area for the 18" altitude bearing I picked up from Bailey Ceramic Supply!

Ambrose Liao

Tuesday, December 2, 2008

Moon, Jupiter and Venus conjunction

My wife, Cynthia, called me on the way back home from work last night and told me that I had a present waiting for me when I came out of the subway. A gorgeous moon with two sparkling diamonds floating by her. I couldn't wait!

When I did come out, I had to walk out of the busy downtown Bethesda high rise area to see it and I was floored!

The photo above doesn't show how sparkling Venus and Jupiter were in the night sky. If you zoom in to Jupiter (the one on the left), you can see one of it's moons!

Taken with a Canon 30D with a 18-85mm IS lens handheld.


Monday, December 1, 2008

Third Upgrade of the Coulter Odyssey 1 - The Drive System

The basic Alt-Az mount for a Dobsonian is a very basic, yet fully functional way to point your scope at the stars. However, when you're using a high powered eyepiece, objects that you locate move out of the field of view very quickly. The time can be as short as 30 seconds. This isn't enough time to get a really good view of a star or the moon. The next upgraded needs to address this.

I originally heard about a device called an equatorial platform. This device rotates the scope essentially in harmony with the rotation of the planets around the earth (sidereal rate). It's quite ingenious, but pricey. The least expensive one I could find new was around $500-800!

There is also the option of building one yourself, if you have the woodworking and electronic skills necessary to do the job.

Since my hobbies are woodworking and electronics, I thought it was an ideal project to take on next! However, as fate would have it, I came across a used Tech 2000 Dob Driver II Rim system for sale for $100 on The two motors used in the Dob Driver II are more expensive than $100. The red handheld unit where all of the "smarts" of the system are, is where all of the costs are located!

The Tech 2000 Dob Driver II system is also quite ingenious and much simpler in implementation. Instead of mimicking the rotation of the earth, it simply adjusts the alt-az mount to track the object you're observing. It contains two powerful stepper motors (one drives the rotation of the scope and the other drives the altitude of the scope) and with just a few seconds of training, will track an object without tedious polar alignment or telescope levelling which are critical for an equatorial platform.

New, their models sell for around $750 to around $1150! I was able to find a NOS (new old stock) Rim drive system for only $100 on This is almost as good a deal as my Big Dobsonian was!

More photos of the Dob Driver II here:

I've got all the parts I need for upgrading the system, now all I need to do is to mount the drives and install the altitude bearings to have it work with my Coulter.

I've already notched out the baseboard for the azimuch motor:

Next, I need to cut out a circular area out of the rocker box so that I can add an 18" altitude bearing to the right side for the Rim drive motor.


Second upgrade for my Coulter - Focuser

I still have the spider to upgrade on my Coulter, but a more urgent needs was to upgrade the focuser. The original focuser was a fairly straightforward rack and pinion 1.25" focuser which worked well, but was limiting in that I couldn't get my dSLR (Canon 30D) to focus. The Canon needed about 2 or 3" more inward travel. I decided to go for a low-cost 2" low-profile focuser. The ones I found on the popular telescope stores were kind of pricey at around $160. This Orion one looked good, but was out of my price range.

I was fortunate in finding the same focuser from It was only $100 used. It didn't have the exact same coloring as the Orion focuser, but it functioned and looked identical.

The focuser allowed me to achieve enough in-focus to use my dSLR! I was very happy.

What is even more spectular is that with my dSLR and the scope combination giving me 2,400 mm, the moon fills up the frame of the dSLR almost perfectly. This is a full-frame (1.6x crop factor) shot of the moon.

Next up: the drive system!


First upgrade of the Coulter - The Cell

After reading up on the Coulter on and on Kirk Mona's excellent Coulter Odyssey web page (, I decided to upgrade the primary mirror cell and focuser first.

The cell came from JStar which is a one-person operation based in California. The cell is fairly heavy duty, but very easy to adjust and to install. 

All of the photos of the cell and spider are here:

After the installation of the cell, the scope looks like this:

Because of the dramatic reduction in the weight of the scope's cell, the balance was changed so I needed to add a couple of hand weights to the scope to rebalance it.

The new cell dramatically improves the cool down times of the scope. I can start observing less then half an hour after taking the scope outside. Whereas before, I would have to wait 2 hours or so before observing.

All of the photos of the scope with cell are here:


Updating the Coulter Odyssey 1 13.1" Dobsonian Telescope

Back in March of this year, I was fortunate to be able to purchase from, a used Coulter Odyssey 1 13.1" Dobsonian telescope in essentially pristine condition. It's about 5'5" tall and weighs around 90 lbs. It came with 2 Televue eyepieces, a 7.4mm and a 32mm Plossl. It also came with a 2.5x Televue barlow and a Telrad Finder. All for $175! I was very happy. The original 8x50mm finder scope was pretty much worthless, so I removed it and sold it.

The telescope is a 1,500mm (59") focal length and a f4.5 focal ratio. Very powerful and very fast, too!

Here's how it looked when I first picked it up:

Here's the whole batch of photos that I took of it when I first got it home.


Upgrading my Coulter Odyssey 1 13.1" Dobsonian telescope

I haven't really mentioned this much before, but I thought I'd start entering some info on my upgrading of my Coulter Odyssey 13.1" Dobsonian telescope. I originally bought this back in March of this year and love the views from it, however, found out fairly quickly that it's a bear to set up and to use (bump, nudge, bump, etc...)

Shortly after that, I decided to update it and improve it as much as I could do inexpensively. The key word is "Inexpensively!". It's very easy to spend big $$$ on upgrades. I hope to do this with a minimal amount of money and more sweat equity.

Wednesday, November 26, 2008

Moon Sliver 11-22-08 before 8:00 AM from DC

I ventured forth from an early morning slumber to capture the waning moon near dawn. It's a stack of 30 images processed in Registax. Not perfect, but considering the hour, pretty good. I like the tonal range for this image. There's some sky glow from the rising sun, but overall it looks pretty good. This was taken with my Canon 30D through my Coulter Odyssey Dobsonian telescope.


Wednesday, November 19, 2008

New moon (my best yet!)

The skies finally cleared around Washington, DC on Sunday night (November 16, 2008). I went out with my newish Canon 30D and my upgraded Coulter Odyssey and took about 100 photos of the moon. I stacked 24 images in Registax and came out with this photo which is my best moon photo yet. The smallish thumbnail is above, but I highly recommend you check out a larger version on

It's not perfect, but it's a gigantic leap up from my early attempts. I look forward to getting the Tech 2000 Dob Driver II Rim drive on my scope so that I can take photos with less effort in "bumping" the Coulter to track.

 Ambrose Liao
Well, it's been many, many months since I've posted but I'll try and make up for lost time. I've been fairly busy with my astrophotography. Fall is finally here and the skies have been relatively clear recently. I've finished my PMP certification course so can focus on my hobbies again.

First off, I'll be working on upgrading my Coulter Odyssey 1 13.1" Dobsonian telescope. I've already upgraded the primary mirror cell to an aluminum 3 point cell.

I've also upgraded the focuser to a 2" low profile crayford so that I could have enough in-travel for my dSLR.
Over the summer, I picked up a Tech 2000 Dob Driver II Rim version computerized tracking system for my Coulter. I'm hoping that the DDIIR will allow me to track the moon and stars much more easily so that I can improve my astrophotos.

I opted for the DDIIR because I didn't want the complexity of a GoTo scope, yet I wanted it to be able to track an object. The beauty of the DDIIR is that it will track any object (moon, stars, sun) with just a few seconds of guiding. This should be more than adequate for my purposes.

I've started cutting the base for the azimuth drive and am awaiting the arrival of an 18" new baltic birch altitude bearing for the DDIIR.

More later!
Ambrose Liao

Now I'll be working on a Tech 2000 Dob Driver II Rim installation on my Coulter.

Friday, May 23, 2008

Basic Photo Equipment and Scopes

Let me start by outlining my basic photo gear as well as my telescopes.

I started in astronomy back in September of 2007 with the purchase of my first scope: the diminutive but very capable Astronomy Technology AT66ED APO refractor telescope. It's relatively small, but the optics are truly apochromatic (without color). This is critical for lunar photography because of the very bright nature of the moon against the night sky. The difference in brightness causes chromatic aberration in many lesser scopes. Along with the scope, I also bought a very heavy duty tripod and mount. The Universal Astronomics Unistar Light Basic which suits the AT66ED APO very well.

I've posted a photo of the AT66ED APO here:

I already had a Canon Powershot G7, so all I needed was a way to hook the two together. Luckily, there is a great lens adapter available which is very well made called the "Lensmate." It's solid aircraft grade aluminum and built like a tank. This provides a 58mm thread to mount filters or telescope eyepiece adapters.

Here's a shot of the Canon G7 with a Scopetronix MaxView 40mm eyepiece connected to the Lensmate:

I've recently purchased a lightly used Canon 20D to try and further my astrophotography:

You can see the humongous Scopetronix MaxView DSLR eyepiece mount connected to it. The Scopetronix allows you to use any 1.25" eyepiece with a DLSR. Also shown in the photo are the Seagull 2.5x viewfinder magnifier and the Cactus Canon EOS wireless shutter release.

Some photos next:

New Blog and 1st entry

Hi everyone,

I thought it would be wise to post some of my photos some place central so that I could keep up with postings of my lunar photography and my equipment purchases and techniques.

I'll be posting some today and will hopefully keep it up!