Orion 120ST f/5 Short Tube Refractor - Home at Last

Phew! After months of research and a week of waiting after I ordered it, my new telescope, the Orion 120ST f/5 finally arrived. The scope is mounted on an Astro-Tech Voyager portable Alt-Az mount. Here are a couple of pictures.



Unfortunately I haven't had a chance to really use it yet. I've ordered two eyepieces but neither one is due to arrive until next week. I did scavenge a 25mm Kelner eyepiece (24x power) from an old kid's scope in the basement so I can use that.... except that it's been both cloudy and snowing since the scope got here on Tuesday.

However, the snow stopped this afternoon and I hauled the 120ST out to the front yard. It's daylight and cloudy, but I wanted to test the focus and make sure the finder scope was lined up properly. So, I pointed the scope down the street about 1/2 mile. It turns out that the cheap eyepiece isn't too bad. The focus was crystal clear and I was able to read license plates from 4-5 blocks away (backwards). And I was able to line up the finder scope pretty well.

Actually, the finder tool I use isn't really a "scope" at all. It's a small laser that points at a little glass viewfinder. It doesn't magnify anything, but the laser throws up a little reticule target on the glass which you line up with your target in the sky. The 120ST has such a wide field of view that you don't really need a separate finder. I'm still tempted to get a right angle, correct image 9X50 finder for it also someday, in addition to the EZFinder-Delux, just so that I don't have to contort my back in crazy positions to sight up with something in the sky.

So far I'm pleased enough with the optics. I've heard that some people have gotten poorly collimated copies of this scope and have been forced to return them. There's a 100mm version of this scope that comes with the ability to collimate the objective lens, but this 20mm larger version doesn't have that ability for some reason. (Collimation is the process of adjusting the lens to make sure it is pointed exactly straight down the tube towards the focuser and eyepiece.)

The other bonus is that I've confirmed that I can carry a small chair and a box with the diagonal and eyepiece under one arm while carrying the mount and scope with the other and haul it all outside in one trip. Setup was fast as was teardown. The whole process was really easy, which was extra nice since it is pretty freakin' cold outside.

The next step in the process is to try the 120ST out under clear skies. When my 13mm Ethos and the 4.3mm Antares eyepieces arrive I can then test the focus on the moon and run a "star test". That will also tell me how well the lens takes a focus and how well collimated the objective is.

Instructions and a description of "star testing" can be found here.

More later, when the sky clears up. Shoo, clouds, shoo!