10/27/2025
So I finally finished restoring my dad's old telescope. The main scope is a 10" reflector, f6 which means the main mirror is 10" in diameter and has a prime magnification of 6x. The second telescope on the big one is a 4 inch refractor, f10. The restoration included replacing the 2" secondary mirror with a 2.6" mirror. This doesn't sound like much but the area of a 2.6 mirror is much larger than a 2" mirror. I also replaced the 1.25" focuser with a high precision 2" focuser that can support my Nikon D850 that weighs 2.22 lbs and can be adjusted to the width of a hair. (This sounds simple but actually was a very involved process to get the focus to adjust at the width of a hair for both use with the camera and eyepiece.) The telescope has been basically sitting in storage for the last 45 years so there was considerable cleaning and painting that was needed. Last night I started the process of polar alignment. This is a slow process where I align the telescope to point at the Earth's rotational north, not the magnet north. The telescope weighs over 260 lbs and is not meant to move so rotating the mount just 0.25 inches is a big challenge. It will take many nights to get the alignment setup. (The reason why a polar alignment is important is to have the telescope counter the rotation of the Earth. The precision needs to be very high. A star will take up 5 pixels and there's over 8,000 pixels across the sensor. If the telescope is not tracking the stars exactly the star might be elongated and be 3 pixels high & 20 pixels wide, resulting in star trails.) Ideally I would like to be able to take a 1 minute photo without the telescope showing more than 3 pixels of movement. Currently I am only at 4 seconds before I see trails.
A challenge that I am facing is that the mount was made in the early 70s with a very high precision AC motor that uses both voltage and frequency to adjust the speed that it turns. If you ever had your lights flicker when the dishwasher ran or some other appliance, there was a change in voltage. The telescope can't have a change in voltage or frequency unless deliberately done so. That flicker that we see will slow & speed up the motor resulting in trails.
Yes, I know this post is long. This is much easier to read than much of the political posts that are on Facebook. To capture the photos I do, whether astrophotography, landscape or nature, takes time and an understanding of your equipment and the environment. It also takes an understanding how to process the photos. My photo of Comet Lemmon took roughly 15 minutes to capture & nearly 20 hours of computer programming time. (Comets will take at least 3x the processing time than other astrophotography pictures because of the number of times you need to process it.)
