Peter Drew

A pair of "Marigolds" will give you a good manual grip. PST components can be freed easier after the careful application of some hairdryer heat. 🙂

Whilst we appreciate Tony's kind words, myself and Andy are responsible for the running of the Centre but the 40 years development has been shouldered by countless others. I'm pleased to report that the telescope has been successfully dismantled, optics cleaned, corroded internals refinished and the rebuilt unit collimated and ready for collection. 🙂

Start with a small fast refractor, that's a "toe dip". A "Faststar" or "Hyperstar" is a full body plunge. 🙂

The pictures look good enough, there's no way that collimation at that level would produce the issue reported

I think it can be repaired. If you could get it to me I would do my best to sort it out for postage only. 🙂

Sounds to me to be more likely a mechanical-optical issue rather than focusing or collimation. It's possible that the stronger springs have distorted the mirror cell, how free is the primary mirror in the cell? 🙂

Good tips but I would question the "problem" of the tilted main prism. I have worked on around 20 PST's and each one has exactly the same forward tilt. It is my belief that this is intentional to avoid unwanted reflections. The prism is a pentaprism which produces constant deviation of the light path so a small tilt does not affect the optical performance. 🙂

Celestron certainly use a smaller mount for the 4" and 5" models and use the same larger mount for the 6" and 8". I have both mounts. 🙂

Could be John Nichol, ("Glasspusher") on this forum

My deforked 12" SCT runs happily on a EQ6 Pro for visual use. 🙂

We all have different levels of interest. Double stars for instance, low magnification one star, high magnification, all being well, two stars and that is all the detail you are going to see. Whereas the Moon.............. 🙂

If weight and general larger mass are not a serious consideration I would favour the 10" F5 every time, better resolution, light grasp and a more forgiving focal ratio. 🙂

My 30" Dob requires a tall step ladder. The focuser is on the E side so it's a push away action. Either side or action has its problems in the dark, there is little difference between the telescope moving away from you and the sensation of falling backwards. Smoothness of movement is critical, a jerky movement can easily unbalance an observer. No clear advantage over E-W focuser. 🙂

If the corrector lens is plano-concave I would expect the plano side to face the diagonal. 😀

For "lunar and planetary stuff" I would seriously consider a Maksutov. 🙂

Dramatic image , best Newton rings I've seen for a while 🙂. Tilting the camera can reduce/eliminate the rings, adapters to achieve this are available.

I think most agree that such sightings have been reported since the 1950's and that no verifiable contacts have been made with aliens in the 70 odd years since. This suggests to me that, if aliens exist, they prefer to remain anonymous and out of touch. If so, why would they blatantly advertise their presence by displaying easily observable lighting systems? 🤔

A pair of Coronado PST's makes a good H-Alpha binocular. 🙂

They certainly did have sightings, Von Daniken said so. 😀

A few years ago I was commissioned to fit an early model of the Fujinon 150 to a Starchair. I had a number of "rides" on it and found it quite comfortable, sadly the project didn't coincide with some clear weather so I was unable to try the binocular astronomically. Both the Fujinon and the chair are pretty heavy. 🙂

You can buy anti galling preparations to mitigate against corrosive seizure. 🙂

Never counted them but must be in three figures. 🙂

I had the same email. Not sure what precipitated it. I think the recent furore over the DPAC of a telescope put a number of manufactures in the spotlight. No affiliation with Astronomics, just a subscriber to Cloudy Nights. 🙂

Unless you have an OCD about dust then it's best left well alone. Apart from any potential accidental damage, removing the mirror for cleaning can open a raft of collimation issues. 🙂

It was the Skywatcher solar mount, I didn't notice what tripod, the LS50 was not mine. The issue was managed by using both hands, I'm not advocating one system over the other but given the choice I would prefer tilt tuning. 🙂