10" f/8 Moon and Jupiter Pt.2

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While playing about with the collimation in daylight I discovered the secondary mirror was rattling and rotating in its mounting tube. So I cut a piece of soft foam to stuff behind the mirror. One less thing to worry about.

Next I removed the primary, removed the fan from behind the mirror and fitted it on the back of the cell. I then added another spring to each collimation screw and added a washer under each wing nut.  Now adjustments were firm and without backlash.

Having tilted the OTA gently upwards on the bench I inserted the Cheshire alignment tool and re-collimated from scratch. Looking from in front of the OTA past the secondary was the easiest way to get rough alignment. Finally I had everything overlapping as seen through the Cheshire.

The Moon was climbing over the hedge as I put the OTA on the MkIV mounting and connected the drive box. Now I could see two tiny craters in Plato and lots of shading in the relief of Plato's  floor. Turning on the fan only caused vibration without any improvement in seeing fine detail.

Jupiter was still soft despite being high overhead. Worse than last night.

Dinner over and now I'm going back out to try and get some handheld snaps with the Canon (short zoom) digital camera. The best of my results can be seen above. After I removed the rubber eye cap from the 20mm eyepiece my simple tubular camera adapter was much too loose. It used to fit my missing, rubber clad, 20mm no-name Plossl perfectly. I believe the eye relief was also better than the 20mm Meade 4000. This sloppiness in the adapter needs more work in daylight to ensure effortless centration of the image in the camera field. The 20mm provides 100x visually on the 10" F:8.

My guess as to the Moon's altitude was wrong yet again. It had only reached 45 degrees on the digital clinometer when I finally packed everything away.

Click on any image for an enlargement.

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