The Megrez 80SD set up on the Losmandy G11 mount ready for Astrophotography.
The Megrez 80SD set up on the Losmandy G11 mount ready for Astrophotography.
The Megrez 80SD was purchased in 2003 as a travel telescope. It soon became a lunar and solar scope also. The latter by adding a mylar filar filter to it. It was used during many Halloween nights so show the kids the moon.
In 2022 I picked up a dedicated Astronomy camera and was amazed at the images that I could capture with the now aging Megrez. This refractor, being a doublet, had purple fringes around bright objects. I knew this would be an issue when I bought it but it was primarily used for visual astronomy and the fringes were barely noticeable. This scope is built like a tank and after more than 20 years of use still looks and has the mechanical motion like it was new.
I needed a travel mount for the Megrez 80 and I made an Oak mount for its first trip to New Mexico.
The initial intent is to use an old, original Megrez 80SD at 480mm (which tests at 501mm) to test the setup.
This has an Orion field Flattener added to the optical path.
3D printed bracket that supports the ZWO Electronic Automatic Focuser (EAF).
Since the Megrez telescope is a 25 year old doublet I wasn't expecting much. My first three minute exposure of M31, the Andromeda galaxy, was better than any film shot that I made in the past. After fighting some dust spec issues on the camera sensor the results were amazing. There is a bit of a blue fringe around bright stars, but the image was sharper and had more detail than I expected. While it was a great learning set-up I really wanted better quality. Recently I picked up a 100mm ED scope that should eliminate the blue halos around stars.
The ASIAir Plus is amazing. I am able get the perfect focus, slew to the target (with it making suggestions) and plate solve to confirm the location, set the exposure time and number and see the raw results. All of this is controlled from an iPad. The clouds had a few nights off during the full moon and I was able to get some five minute subs to combine them into the images below. While this takes longer to get the shot than underwater photos do the chance of dying while getting the shot is far less.
The tube rings have a Losmandy D-dovetail plate on the bottom and a plate of 1/4" aluminum on top to hold the auto guider, ASIAir and a Rigel Quick Finder. The plate was cut with a jigsaw (I do woodworking, not metalworking) and the edges were filed and sanded smooth. The mounting holes for the autoguider and ASIAir shoes were tapped into the aluminum.
Getting the focus correct required paying attention to the elements between the scope and the camera's focal plane to get the needed 55mm back focus. Using the photo from left to right...
On the Megrez I used a 2" SVBONY Telescope Camera Adapter with M42 threads.
This screws into the Orion Field Flattener for Short Refractors.
Next is a 16.5mm long 44mm to 48mm threaded spacer that came with the camera.
This attaches to the ZWO 2" filter drawer (21mm long)
and that finally connect to the ZWO camera
An additional 48mm to 42mm zero length adapter is also in there. This came with the camera also.
The transit of Venus is when the Venus crosses between the Sun and Earth. This happens twice eight years apart and then there is a 121.5 year gap before it happens twice again repeating the cycle. For most of us this is, at best, a twice in a lifetime event. Each of these transits takes about six hours and that's only if you are in the perfect location on Earth. For the local astronomers in St. Petersburg we had about 20 minutes. Fortunately the morning clouds cooperated and we were able to get a great view of the first of the two transits in my lifetime. After seeing the transit I quickly packed up and made it to work early.
The second transit in this set happened in 2012 and was visible on the west coast of the United States, but for many it was clouded out. I didn't attempt to see it the second time. The next Venus transit is December 10th, 2117. If you were born in 2024, when I wrote this, you will be 93 years old.
The Megrez 80 ready for Transit of Venus at about 6:45am on 6-8-2004. The solar filter and alt-az mount were a perfect combo for this event.
Venus is the black dot in the upper right of the Sun. This is a view using a camera looking through the eyepiece at 6:59am.
More than 100 local astronomers lined up at the North approach of the Skyway Bridge for the low Sun view and the transit of Venus.
