Hodgson Observatory

As many of you know I have gotten into Astro Imaging in the last year. The other day I noticed my old 6″ F5 reflector just sitting in the corner of the garage and decided to see if it would make a fair imaging platform for cheep. It is on a Vixen Polaris “Clone” mount with dual axis drives. The problem with the drives is they had no guide port for imaging. I searched around the web and found an interesting modification that I could do to the hand controller to add an ST4 guide port to it. Here is the link to the article.

http://www.store.shoestringastronomy.com/eq_mod.pdf

Rather than purchase their kit I picked up the parts at Ace hard ware and did the mod my self. Here is the had controller with the new ST4 guide port. The white cable at the bottom of the controller.

I also had some adjustable rings and an old 60mm Celestron refractor that I could use as a guide scope. After some “Engineering” I got the whole thing together and working to my satisfaction. It turned out pertty nice, and seems to function well.  I wanted a Wide field system that was compact, light weight, and portable. I think this little rig fits the bill. Here is what it looks like.

Last night 6/25/09 I got to give it a try and it worked flawlessly. The image it produced was very pleasing to me and gave me the wide field I was looking for. The light pollution in Sioux Falls limited my exposures to 15 seconds each so I took 130 of them and then stacked and processed them. Here was the outcome.

Not to bad for a bunch of parts laying around!

JJ

The SEAC recently rescued a vintage 16″ Cave Newtonian reflector. It was stored in a machine shed at a local college. The scope is being parted out to club members that wish to refurbish, and contribute to it’s completion. This instrument will be used for our club’s public out reach, and club member research. It will be housed in and observatory building at the Hodgson Observatory site upon completion. If you are interested in following an image history you can visit the SEAC image gallery here: http://www.inskysd.org//gallery/categories.php?cat_id=74]

JJ

Over the spring and summer I have been working on building up an imaging system. I already had a very good German Equatorial Mount. It is a Sky Watcher EQ-6 with GOTO and an auto guide port. A rule of thumb for mounts and Astro Photography is to not exceed 1/2 of the mounts rated load limit. The Sky Watcher EQ-6 is rated for 40 lbs of optical equipment.

I wanted a refractor of about 4″ to 5″ aperture as the main imaging scope. The Orion 120mm F8.3 looked like a good starting point so I purchased it. The focuser was junk so I replaced it a GSO Crayford unit. I also set every thing up to operate in a 2″ mode to reduce vignetting.

Now I had to decide how I wanted to guide the system. Once again Orion to the rescue. They had a very nice 80mm F11 guide scope and rings for a reasonable price and it is very light. It also came with a very crappy 1.25″ focuser. I replaced it also with a GSO Crayford 2″ unit. The guide scope mounts piggy back on the 120mm unit. Both weigh about 25 lbs total.

I needed a good guide CCD. Here is where I could use a web cam or go for a dedicated guided camera. Orion had a great little guider call the Star Shoot Auto Guider. It is a complete package with cables and software. Plug and play system.

The nice part of this system is it all is compatible with each piece of gear. I loaded the softwares and powered every thing up and it all talked right the first time out of the box…Sweet!

The camera I decided on was the new Canon XSi / 450D. I chose it for its features. It has a Live View mode, 3″ LCD screen, and new software that allows for automatic imaging. Once you set this system up you can start it and then go inside and forget it. Check your watch later and go out and start another session!

Too date this has been a wonderful system to use and the images are stunning. Total cost including the initial out lay for the mount and all parts and cameras has been $3700. Not inexpensive but reasonable for a start. I don’t see how you can Astro Image for much less without compromising the system. Maybe a lesser mount with smaller scopes and a less expensive camera could get you in at under $2000. The mount is the most important part of Astro Imaging. It has to be extremely stable and capable of carrying all the weight of the AP system.

In conclusion I hope this gives you an idea of what it takes to get started in Astro Photography. It is a costly investment and your results will reflect the investment. Astro Photography is not tolerant of compromise, especially with the mount. If you are planing on doing AP, start with the best mount you can afford and make sure it has a guide port. If it has a guide port, that is a good indicator that it will be ok for AP.

JJ