'artistic' aircon:
Blade-less fans:
At first I thought there was no more hope for Obby, but after cleaning and accessing the damage, I found that it was still salvageable. The damaged portions were
1. Upper Tube Assembly (UTA)
- secondary mirror coating damage
- Plastic caught fire from debris and burned
2. Primary mirror got damaged by burning debris
3. Nylon shroud melted
4. Truss poles foam melted
'artistic' poles:
Since the optics were all damaged and in need of either coating and/ or refiguring, I decided to go for the best optics and to 'upgrade' my already or 'once' excellent setup. I decided to buy a new secondary mirror from Protostar. I got the quartz mirror with excellent surface flatness and 10-5 polishing finish for the lowest possible scatter. For the Primary mirror, I sent my mirror to Carl Zambuto for accessing the damage. He concluded that my optics had a very good figure and that what was needed was actually re-coating. However, I decided to try his mirror quality and told him to re-polish and re-figure the mirror to his almost perfect mirror standard. It was good choice actually, as he found out that the mirror coating could not be stripped off by chemicals, and in the end it was necessary for grinding and polishing the surface. Since I am using my telescope primarily for observing planets, I decided to go for the lowest scatter and highest surface quality instead of having the maximum transmission like in the past configuration (with OMI primary mirror enhanced coatings)
For the truss poles that were damaged, I took out the foam and sent the poles to be black anodized. For the UTA plastic and the shroud, Rlow helped me to purchase the plastic and the spindex light shroud. Thanks Rlow!
I, together with my wife, did the cutting, mounting, punching holes and sticking (with strong double side tape) of the UTA plastic onto the wooden UTA frame. I bought Protostar flocking material and cut+paste it in the UTA to ensure no stray light reflecting off the plastic. For the light shield that extends out of the UTA, I have made one and good that it was not damaged in the fire. I replaced the velcro that was used as it melted on the UTA.
It involved quite a lot of work on the UTA as Obsession dob's are so beautifully crafted, putting it back was not easy as I did not have the accurate tools to do so. Glad that together with my wife we did it though I must admit i is not as nice as the original, but well, can work should be fine.
Ok, now for the first lights. In fact I took it out a few times to do alignment and testing of the optics; however I did not have a lot of time to do for few hours so could not invite anyone to join. They were short tests of at most an hour each session. I performed star tests quit many times and must say am very impressed with the mirror quality. I estimate that the strehl ratio is definitely higher than 98% which means it is practically 'perfect' quality. In focus the stars had a nice Airy Disc surrounded by clean diffraction rings. In the testing, I noticed astigmatism at quite high powers and thought it was the sling that held my primary mirror has degraded due to the fire and also thought if my secondary mirror was held too tightly. After checking them and realigning a couple of times, it still persists. Also to my dismay, my laser collimator was out of collimation and I had to collimate it back. In the end I star tested with my small refractor with the similar exit pupil and concluded that my eye astigmatism has gone worst! Arrggh.
Therefore, in short the star tests can say was practically perfect with identical intra extra focal patterns at more than 5 rings defocus and almost similar defocus patterns at the most extreme test of only 3 rings defocus. Therefore Carl Zambuto has exceeded the 'very good' mirror I had in the past and I am glad with its quality.
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For planetary, I only tested it on Jupiter and I can say that it renders very sharp images of Jupiter and that fine details especially in the polar regions (tends to be the lowest contrast) were seen well. Since there is no A-B comparison with my OMI mirror of the past, I cannot say conclusively yet that there was 'more details'. More testing is needed to determine if there is truly an improvement in in-focus image basing on memory. However, from the perception of looking at Jupiter, I feel that it may seem to render slightly less scatter around Jupiter and that the fine details stood again slightly better basing on countless times I have used my telescope with the OMI mirror on Jupiter.
Attached are more links of my new 'Obby'
Side view:
View with my favourite observing chair and hand truck (I push the whole setup out of the store-room as ready as it can be):
UTA with flocking. Notice there is no glare in the inner walls of the UTA despite flash photography:
Glad that I have my new Obby!
