Royce 8" f/6 Ultimate Newtonian Performance
Posted 26 September 2011 - 08:32 PM
Living in Florida, I have been enjoying exceptional seeing recently for Jupiter and lunar observing. I have also enjoyed being friends with some very high caliber lunar and planetary observers (two are nationally known names many of you would recognize).
Without getting into a lengthy review, I will simply say I, and my observing buddies, have been very impressed with the 8" f/6 Royce (conical mirror, curved spider, innovative secondary support, etc.). My scope was an early prototype that was made with a Blacklight phenolic tube.
On one evening, we had six high resolution optics in the field: An eight inch f/9 newtonian, a 10" f/9 newtonian, my 8" f/6 newtonian, a 4" Nikon refractor, a six inch Intes f/12 MCT, and a custom figured high resolution SCT. When Jupiter rose near the zenith, the seeing became excellent and the instruments were all pointed at Jupiter. The Royce Ultimate Newtonian produced as fine (in some cases better) image as the other optimized high resolution instruments. Color, contrast, and resolution were top notch.
I like the Blacklight tube a lot. It does not have a rotating focuser like the new aluminum version, but it is super light, and has excellent thermal properties. Heck, the whole 8" telescope is only 15 Lbs! It definitely wins the award for most lightweight, easy to setup and use planetary scope I have owned. And being light weight, it is really held solid on my CGEM mount.
Although my scope came with a fan, it isn't needed. There just isn't much mass to cool, and the conical mirror ventilates well. I have tried the scope with the fan on, and off. Back and forth...the fan just is not needed (in Florida). In fact, I seal the back end of the tube to prevent currents from entering the back of the telescope. I have not had any problems with tube currents and cool down time is maybe 10 min.
I have owned and enjoyed many fine instruments including high end retractors, maksutovs, and other fine newtonians. The Royce telescope is among the best I have owned and observed with. I have seen first hand, and agree with, the comments in the formal Royce 8" f/6 review found in the CN reviews section.
Posted 26 September 2011 - 09:39 PM
Posted 26 September 2011 - 10:37 PM
Posted 27 September 2011 - 04:50 AM
Although my scope came with a fan, it isn't needed.
...in Florida, as you quite rightly pointed out. In Grandpré in France n a night in which the temperature dropped from 20°C to 1°C, you might have come to a different conclusion.
Life isn't fair. We have to fight the latitude, bad seeing, scope thermals,...and you're getting a free lunch (well, apart from the odd hurricane, that is).
Posted 27 September 2011 - 09:34 AM
I've been very interested in the 8" F/6 Royce.
My own scope is built around 10" f/4.5 Royce conical, which has performed wonderfully.
Posted 27 September 2011 - 06:33 PM
Posted 27 September 2011 - 06:43 PM
Posted 27 September 2011 - 07:47 PM
You might be right. As a generalization, I am finding the conical mirror shape, and reduced mass, are functionally important. I did have the telescope in New York for two months in the spring and would run the fan for a few min. during initial cooldown, and then seal the back of the tube. From that point, I felt the mirror tracked the air temperature very well.
I have experimented with fans on my two conicals and have found that I can do without them, despite the large temperature drops typical of the high desert. I suspect that the thinner outer section of the conical acts as a radiator to pull heat from the center and rapidly disperse it.
The dominant issue I have in my local area is atmospheric (fast) seeing, so there is the possibility it could be masking thermal issues on the scope.