Peter Drew

Just like the Queen. ?

I don't think you would notice much difference for EAA use. ?

What telescope are you going to use and is the pier to be a permanent one?, from your appraisal of Rugby it appears you might want to move in the future. ?

You're not the only one intrigued by the Solar Scout. Despite many claimed to have been sold, no reviews or performance details seem to have been reported. I think "Retailer 2" was probably nearer the mark, a combination of an inexpensive 60mm telescope combined with possibly a minimum standard Quark plus the fact that the Quark element could not be interchanged to other telescopes accounted for the low price. I have to say that the advertising for this product was vague to say the least. Still waiting with interest for some real world use report. ?

Further "research" has revealed that the 37" James Gregory telescope at St Andrews University is in fact a Schmidt-Cassegrain. The 37" is necessary to give full illumination from the 36" aperture corrector. As such, it's the largest SCT yet made and the largest aperture in use in the UK. ?

I was using a 15" Grubb refractor at Stonyhurst College(terrestrially) last week as a preliminary to doing some refurbishment work on it. ?

It could well be. The infrared lights on top of the turbines creates an Aurora Borealis effect photographically. ?

I believe that St Andrews University has a 36" catadioptric telescope that has a 38" primary and often claimed as the largest as a result. ?

Many years ago I built the tube assembly to house a 106cm mirror for the Astronomy Centre. We eventually managed to purchase a pre-generated mirror blank but the project to grind, polish and figure the mirror is currently on hold whilst we find a way to mitigate the effects of turbulence from wind farm turbines that now ringfence our location. ☹️

Doing its bit to save the planet? ?

The post title begs the question "useful for what?". A 60mm refractor is ideal for solar sunspots and suitable double star observation but would be less useful for comet seeking. The urban myth that 3" refractors and 6" reflectors are somewhat equal has nowadays been debunked now that good quality examples of each are readily available. What is useful for me, these days, is a larger aperture to come close to seeing what younger keen sighted observers can see with smaller ones so my minimum useful aperture is gradually increasing. The bottom line, probably, is that the higher the quality the smaller the aperture that can be considered useful. ?

Another Celestron NexYZ smart phone mount. The first one has proved to be so good we ordered another for our other observatory rather than having to share. ?

Fullerscopes offered A, B and C quality optics in their Newtonians. The A quality ones were by David Hinds and low expansion glass, the B quality were usually also by David hinds, high optical quality but plate glass. C quality optics were by whoever could make them the cheapest at the time. Refractor optics were either left overs from Broadhurst Clarkson which Fullerscopes took over or made new using the same processes. I think the bronze gears of the MklV mounts were supplied on the export models, Still today one of the sturdiest mounts for the price. ?

I think the tripod tray is just missing its attachment screws. ?

The Postman delivered a Celestron NexYZ phone to telescope eyepiece bracket today. Many of our visitors attempt to image through our telescopes with their phones and obviously have difficulty with accurate placement. Hopefully this will be a great help and it should get a good workout this Saturday if it's clear. Seems a nice piece of kit with good adjustment functions. ?

Best plan so far. ?

My wife had this procedure done on Wednesday of this week after cancelling a previous appointment due to worry about it. She is already marveling at the improvement just a couple of days since, perfect vision at a distance and very little discomfort. Big relief for me as well as I had done my best to persuade her to go through with it. Now looking forward to mine when the time comes!. ?

Also following with interest. I've had some experience with a 6" Yolo version. These TCT's (Tilted Component Telescopes) do have excellent false colour free, high contrast images. Like folded refractors they can be a challenge to collimate initially. ?

Good positive news! ?

I've used the "box" IPD arrangement on several 6" refracting and larger reflecting binoscopes, it does offer a rigid platform. The 6" F8 model in the photos incorporated two opposing racks driven by one pinion such that IPD varied by turning knurled knob. You do need to refocus though after adjustment. ?

Similar mounting systems for catadioptric primary mirrors or any thin edge/thick centre profile mirror. ?

I have the standard aluminium tube one, it was donated so I'm not sure what level of optics it contains. Side by side it outperformed a 127 Skywatcher Mak which might be expected and on a par with a good Intes Micro MN56. Cool down time was considerable and I also found the micrometer based focuser awkwardly placed and fiddly to use. Good colour correction and minimal image shift when focusing. Definitely a lunar and planetary telescope. ?

An interesting variation. I'm struggling to see what obvious advantages it offers over some Dobsonian designs. ?

I think it is likely that the secondary/corrector assembly is preset at the factory and no user adjustment is provided. We have a donated Bresser version and this has the conventional Newtonian type secondary adjusting screws. Because of the design, you can't really use the usual collimating aids, I've found the best option is to use an artificial star and adjust the primary mirror cell screws until the defocused "star" image is both round and evenly illuminated at the periphery. I wouldn't recommend removing the corrector lens, replacing it accurately is likely to be a lottery. ?

The 80ED's are not exactly equal in length but it's the photo that makes them look staggered. The binoscope in the background is my 6" F5 achro made from Skywatcher OTA's. ?