After a few sessions with the Meade ETX-125 it was time to also try the larger telescope, the Obsession F/4 18" telescope. The first tests in house during daytime showed that everything still worked. Only the mirror is quite dirty. It should be cleaned but that can wait. For observations is a dirty mirror most often not really a problem unless it is really really dirty. So for the first test I don't do anything about the condition of the mirror.
One of the problems I found was that the control computer, the Argo Navis, had lost the battery power. After buying a new battery, opening the controller and replacing the empty battery I had to set the date and time again. All other settings are in non-volatile memory so these were kept even with an empty battery. The motor drives worked good and also the motor controller, the Servocat.
Also the Telrad, the device that is used to visually point the telescope to the object in the sky, seemed not to work. After changing the batteries it still didn't work, but after checking again when it was darker, I saw the red rings. So apparently the device works but the rings are too faint to see them during the day.
Another problem, that I had found some time ago, is that the laser collimator was defective. I tried to repair it but without result, so I ordered a new one.
For a first test I brought the telescope outside in the garden on August 20, 2018. It took me quite some time to build the telescope up. That is the problem when you haven't done it for a long time. Also collimation was troublesome. And when aligning it appeared that a connection between the Argo Navis and the encoders on the telescope was not working. After reconnecting everything this problem was solved.
When all was done I started using the telescope. But I ran into problems from the start. The Argo Navis was correctly initialised and showed where to point te telescope for a selected object. But the goto-button on the hand pad didn't do anything. The telescope did no automatic goto. So I moved the telescope manually following the directions on the Argo Navis. The object was perfect in the eyepiece, so the Argo Navis was functioning correctly. But the object did not stay in the eyepiece, so apparently the guiding function of the telescope did not work. So the observation session came quickly to an end. But what I had seen through the telescope was multiple times better than what the ETX-125 showed. Not strange given the different sizes of these two scopes.
After considering what could be the problem I decided that the problem would be in the communication between the Argo Navis, which was working correctly, and the Servocat. If that communication is not working then the motor controller doesn't get the information to drive the telescope in the correct directions and also doesn't get the information to guide the object so it stays in the eyepiece. I checked the documentation and my old notes and found that probably the baud-rate of the connection was not correct and that I was using the wrong serial port on the Argo Navis.
So on August 22, 2018 I went out for a second trial. This time building up the telescope, collimating the telescope (during daylight) and aligning the telescope went a lot quicker. This time the automatic goto and guiding the object worked perfectly; even better than on the ETX-125. So, after some visual observing I decided to try to take pictures with my Olympus OM-D E-M1 camera. I needed to use the Televue 2x barlow to get the camera to focus. I made a number of movies with the camera of Jupiter, Saturn, Mars and the Moon.
I ended the evening with some more visual observing. Light pollution especially because of the moon makes it very difficult to see faint objects like globular clusters or planetary nebula. Open clusters were easily visible. And the moon and planets were stunning!
The next day I processed the video's that I made. First I had to convert these from MOV to AVI with VirtualDub. The next step should have been Registax, but it appeared to work better by first processing the video's in PIPP; that gave a first alignment of the images and also skipped the bad images. Then the processing in Registax worked better. But for Jupiter and Mars I was unable to get details. Apparently the images were overexposed. So for a next time I need to find out how to regulate the exposure for video's. Luckely one video of Jupiter was shot while clouds were drifting over Jupiter. That dimmed the planet sufficiently to get visible details. With wavelet processing in Registax and further processing in Photoshop I got good results.
The exposure of Saturn and the moon were apparently much better because I got a lot of details while processing these in Registax.
The results are very good. But look for yourself in the gallery.
Update August 28, 2018: another session with my Obsession telescope. This time I was able to take also a good video of Mars. After processing in ImapgesPlus I added this image to the gallery.
Obsession telescope
Jupiter, Olympus OMD E-M1, 120 of 480 frames
Moon, Olympus OMD E-M1, 1009 of 2250 frames
Saturn, Olympus OMD E-M1, 870 of 3480 frames
Mars, Olympus OM-D E-M1, 372 of 1493 images stacked
