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 www.camerafilters.com 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 www.astromart.com 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 Craigslist.org 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

3 comments:

Peter Dyrholm said...

I really like your lunar photos. Very very nice, crisp and free from noise :-)
That red thing sure is hmm huge....

I have just been looking at possibly doing digi scoping as a cheaper alternative to fixed focal length lenses... but $2000+ yeah let's just say I have a 4 year old daughter ;-)

Every now and then I am lucky to get a kitchen pass to go to the mountains but I hear you with the balance of family and hobby...

ambroseliao said...

Indeed. I have 2! An 8 year old and a 6 year old who keep me going during the day! I have tried VERY hard to keep the budget low. I haven't spen5 more than $300 on any one item and luckily, my wife has been very supportive: especially after the jewelry I bought her last year :-)

My biggest deal was the Coulter for $175 which included the two Televue EPs and the 2.5x TV Barlow. The second is probably the Canon 30D which I bought for $300. It had been dropped but was easily repaired. Then lastly, is the Tech 2000 Dob Driver II which goes for over $1000 new, I bought it for $100. The one I picked up was from 1995 but looked absolutely new.

Thanks for posting Peter,
Ambrose

Cliff Capers said...

Ambrose -

Are you still around? I have a Coulter Odyssey One and started reading your log and links. Many of the links are now dead. I would love to get in touch with you about upgrade information if you are so inclined.

Thank you and good viewing!!

Cliff Capers