Peter Drew

I made loads of telescopes for loads of people but never loads of money!. A "labour of love". 🙂

My oldest telescope is a 3" brass refractor by Davis of Cheltenham, circa late 1700's. My first self built telescope that I still have is a 90mm Maksutov made mid 1970's. 🙂

It's a little known fact that Rusted and myself are clones, although he is a later version. So much of our experiences and current activities are mirrored, we are both DIY'ers, build our own telescopes, mounts and observatories. My 8.5" F12 refractor and mount are built from whatever was to hand at the time, my OTA was made by joining two undrilled 8" Newtonian tubes supplied by OOUK. The mount is on top of a concrete block pier. Before retiring, making folded refractors was part of my business resulting in over a dozen including several 8" F20 to F25. As Rusted says, they can be tricky to build and collimate, but as with most things, once you know what you're doing it's reasonably straightforward. 🙂

I well remember drooling (Drewling?) over this article at the time. I did have a 12" F15 objective for a while, I intended to build a folded refractor but I ultimately sold it at a price I couldn't turn down and it ended up as the objective for a Camera Obscura. I still have the folding flats should another 12" crop up. 🙂

🙂

If the internal nut is not captive then once loosened it wont tighten again. You will need to undo the backplate/focuser assembly and reach in to either remove the nut or tighten it. Fortunately it's the 102mm so large enough diameter to do this!. 🙂

Exactly my experience as well. ☹️

A brief look at around 6.30 this evening. Mars not really high enough and the dome and equipment not really settled but despite this I still had one of my best views so far this year. Could use 400x on the SW 150ed and 500x on the 16" SCT but 100x less on each was better overall. The SCT just shaded the 6" again which says a lot for the SW. 🙂

I have a 150 F5 Startravel and 150 F8 Evostar. Either is at the limit of an EQ5 equatorial for visual use, an EQ6 would be more suitable for imaging. The two telescopes are both a compromise when it comes to visual and imaging, the best choice boils down to which aspect the interest is biased. There are a lot more DSO's than planets! 🙂

Looks to be a right pain to collimate! 🙂

I did find what I suggested to work best for me, specially with large secondaries. Any combination is a big improvement over the supplied arrangement. 🙂

I would do it slightly differently. I would have the screws bearing directly on to the steel washer and the plastic disc/s between it and the top of the holder. The adjustment screws, which should be rounded at the tips, will not dimple the steel washer and the plastic disc/s will allow the secondary holder to rotate smoothly by hand if necessary. Screws bearing on plastic discs could lose their tension as the plastic deforms and alter the collimation. Or whatever works for you! 🙂

Can't say I'm "fascinated" by any particular constellation but I do enjoy the drop down through Perseus, probably as with others, the first I took note of. "Scorpio"?, fascinating if you're an astrologer I suppose. 🙂

It is a fact that many auroral displays are below the threshold of naked eye visibility. These can readily be revealed via a modern sensitive camera. Worth trying when there is a significant alert. 🙂

All hobbies can be deemed "useless". Unless you are actually enjoying them. 🙂

Similar to what I can see in my SW150ED though obviously not as contrasty or steady visually. 🙂

Switch off the Moon???? Usually the chorus from DSO imagers. They overlook the fact that full Moon gives them the respite they need from agonising over misshapen stars, mount orientation issues, tracking errors, computer malfunctions, the list goes on! 🙂

Welcome to the Ha club! 🙂

Me too! 🙂

David retired from mirror making when he became a telescope retailer. He wrote serial numbers on the rear of his mirrors which ran into 1000's, those with the suffix "A" were better than 1/8 wave, usually much better! 🙂

End of an Era indeed. I was pleased to have had a nearly 30 years span of business and social involvement with David Hinds. Along with Rob Miller, David and myself founded AstroSystems and used 100's of his optics over the years, all of premium standard. 🙂

This thread has reminded me of this issue which was raised on Solarchat some years ago now. With regard to sponge ring compression memory, which is a separate issue to loose etalon "up-down" fit, it was advised that if a PST etalon is to be left unused for a considerable time, then the tuning adjustment should be backed off via the tuning ring to release the pressure on the sponge ring. 🙂

I've had a couple of 3.5" Questars pass through my hands, they are indeed fine telescopes and at their launch provided a gulf in performance between them and similar apertures. More than 50 years on, there are many modern telescopes that will deliver equal results and better for some purposes at much lower cost. I have an excellent ETX90 that gives a Questar a good run for the money which set me back £200 but obviously doesn't have as good a fit and finish. I also have a watch, a Russian tank Commanders model, no less, it said so on the box when I bought it in a transport cafe for £3, I didn't get a battery with it though. It keeps as good time as far as I'm concerned as a Rolex. So, if "bling" is your thing and you can afford it, get a Questar, Rolex or whatever. 🙂

The problem is, the prism used in a binoviewer is a beam splitter, this sends half of the light to one eye and the other half to the other eye. Therefore the eyes get only half of the input light and the brain, unfortunately, doesn't recombine the light. With binoculars or binoscopes you get the full amount of light in each eye, the perception, in this case is that the combined light appears to be brighter than a single telescope of the same size. 🙂

Just look at anything during the day Steve, then close and open one eye, the view doesn't noticeably get brighter or dimmer. The brain doesn't stack two images but likes the two sets of signal provided by two eyes rather than one signal and one noise to sort out. 🙂