Peter Drew

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 find it difficult to believe that this latest version of the C6 OTA has had over 3lb shaved off the weight of the previous ones. The originals were designed to be as light as is practically possible, a 3lb saving would take at least a CF tube and leaving out either the primary or corrector to achieve.

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. ?

The residual spots may well be where the coating has oxidised. If so, no amount of soaking or rubbing is going to make an improvement. The test is to look through the back of the mirror towards a bright light. From the look of the "after" image I would think the mirror coating has a few years left. ?

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 had a 12x40 and 20x60 "Tento" binocular also quite a number of 10x50's as I used to dismantle them to make good quality finders. I currently have a 8x40 "Tento", all have been excellent. You're right about the distnctive aroma! ?

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. ?

The Astronomy Centre will be doing "Stargazing Live" as usual this year. ?

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. ?

Trial parallelogram mount for my 80ED binoscope prior to making a heavy duty one for my 6" F5 achro binoscope. ?

And more reliable! ?

Progressing nicely, if it was easy to do, everyone would do it! No reason why your binoscope should perform differently to mine as they both have the same optics, I've been very pleased with mine and have just knocked up a parallelogram mount for it. ?

Exactly. It's ironic though, that self built binoscopes seem to incorporate easy owner adjustable collimation whereas many high end commercial units do not. Purchasers of the latter often spend extra to have them "super" collimated for high powers. My experience has been that what appears collimated often varies with different users. ?

I tried a Nagler zoom set at 3mm on mine which showed that it would take 200x. Or it would if I had a pair of Nagler zooms! ?

I use steel tripods in the main as they come with the telescopes and I find them adequate. If I need a "serious" tripod in either wood or aluminium I build my own as there are better designs available. ?

Stack of plastic cups? ?