Peter Drew

Mono imaging for solar is the way to go, you can add colour to choice in post processing. 🙂

"Guilty as charged". 😀

Yes indeed you can. I have made several in the past, I have a 13" "optical window" from one at present. They do enclose the tube of a Newtonian, keep the dust etc away from the optics, reduce thermals and of course eliminate spider diffraction. Their downsides are significant increase in weight, cost and susceptibility to dewing up. 🙂

I think I could claim that Exchange and Mart effectively launched my career. In the mid 1960's I was making telescopes as a hobby and advertising them in E&M. If more than one wished to purchase a telescope I made more to supply the demand. Eventually this became so time consuming I decided to go full time professional. The rest, as with Caxton, is history. 🙂

Current corrector plates are produced by evacuating parallel sided discs against a former that has the opposite curve to that of the finished corrector rather than a cylinder, the rest of the process remains the same. When I made Schmidt-Cassegrains and Schmidt cameras in my early professional career the optics were made by Jim Muirden. Jim hand figured the difficult correctors from scratch!. The figuring for Schmidt camera correctors was interesting, Jim introduced a thin wire into the field of the test apparatus of a thickness that when the image of the artificial star could be completely occulted the star image was smaller than the resolution potential of the film available at the time. 🙂

If you are going to get a 150 Flextube anyway there would be little harm in giving it a try. It would by no means be ideal due to the extra weight and longer moment arm, the tube being a larger aperture than the 4se will place the centre of gravity further out from the mount and the extra length might foul the mount at high elevations. A DSLR will add a fair bit more weight and restrict imaging to snapshots of the Moon and bright planets. If you are serious about astrophotography you would be better off investing in a setup that is designed for the purpose. Welcome to SGL. 🙂

Never mind, probably just a comet. 🙂

I'm watching your video more than anything this Christmas day! 😀. The bracket that holds the worm is connected by the two large hexagon screws underneath it, if these are slackened the bracket carrying the worm can be pushed closer to the wormwheel allowing the worm to engage with the wormwheel. The problem has to be the result of one of these issues.

Just had another look at the video and I might have suffered an optical illusion as at a closer inspection it now appears that the wormwheel might not be turning. If this is the case, then the worm is not engaging. The worm would have to be way out of adjustment for it not to engage as the pitch is quite coarse, can you rotate the mount without operating the cable and see if the wormwheel turns freely past the worm? 🙂

According to your excellent video, the cable operated worm and the engaged wormwheel appear to be working properly. What is not happening is that the wormwheel is not moving the shaft that it is fitted to. I suspect that there is a knob or somesuch in this area that locks the wormwheel on to the shaft and thereby turning the mount. 🙂

On a budget, consider a Newtonian reflector, they are the cheapest, fastest apochromat available. 🙂

I discovered this last year. I accidentally breathed on to my eyepiece which produced a light misting. Instead of waiting for it to clear I continued to look at Mars. As the mist cleared it reached a point where the filtering was just enough to reduce the glare but at the same time revealed the best detail. I tried this again recently, on purpose, and it still works! 🙂

Sanity check for an imager? Whatever next! 🙂

Never mind the cigar, have a stiff drink in consolation. 😀

An interesting and well executed design. As an enthusiastic builder of large refracting binoscopes I have wrestled with the problem with mounting them over the years. I have built several versions of chairs that carry the observer as well as the binoscope with varying success, my main problem, as yet unresolved, is isolating my heartbeat, this produces an annoying "tick" to the view at the higher powers that binoscopes are capable of. As a result, I have reluctantly reverted to parallelogram mounts. I also build "reverse" reflecting binoscopes that don't have the overhead neck ache problem, I have also recently fitted the Celestron StatSense Explorer system to my 300mm model but not yet had the opportunity to use it. 🙂

After fixing the problem I would probably bond the plastic component back on rather than invest in a riveter and rivets for a one off job. 🙂

My first telescopic view of Mars this apparition due to various circumstances, around 6pm Wednesday evening. For convenience I dug out my 1980's orange C8 equipped with a Baader zoom eyepiece. At the 8mm setting 250x Mars looked small and the brightness swamped the detail, surprised anyone can see anything at less magnification? Replaced the Baader with a TV 6-3 zoom and at around 350x Mars looked a lot better, various albedo markings became obvious and the polar hood was evident. Very brief observation due to health considerations but glad to have an opportunity before Mars recedes. 🙂

Although you can't eliminate human error, dovetail clamps rather than the dovetails themselves, are often inadequate. Specially the dual fit versions that result in too shallow a holding face and don't get me started on the spring loaded ones. Finally, if you're going to drop an OTA, make sure it's a Mak-Cass. 😱

I would expect the Moonlight focuser to unscrew from the backplate of the OTA. If so it can be replaced by the appropriate Meade visual or photographic adaptor depending on the required use. 🙂

I used the video system to attach a 12" LX200 OTA to an EQ6 Pro and it worked very well for a one man operation. I would have thought that a structure that had a platform to place the OTA on vertically but with a hole in it to avoid the camera unit, would be reasonably straightforward to make. Better luck with whatever comes next. 🙂

Can you clarify whether it is the camera mount that is wobbling where it is attached to the telescope or the whole telescope wobbling on its mount? A photo of the setup would be very helpful. 🙂

The Jones-Bird design utilises a "fast" spherical primary mirror, a corrector lens system prior to the secondary mirror is intended to correct the aberrations of the primary and also increase the effective focal length by around 2x. The design offers an inexpensive system and a reduced physical length. The success of this arrangement relies on the quality of the optics and their relative alignment. Many reports suggest that this falls short of ideal in the mass produced models. 🙂

Daystar etalons and Lunt/Coronado etalons are completely different items. The latter are specially coated glass plates separated by a very thin air gap and the tuning is either by pressure or tilting of the etalon. The Daystar etalon is a cleaved mica chip which performs a similar Ha effect and is adjusted by heating. Daystar have little or no control over the quality of each chip, it is what it it is when cleaved. Daystar then grade the chips, the best go into research level instruments and the rest go into those of descending cost down to a level that Daystar judge to be acceptable. No doubt many are discarded completely. Unfortunately the parameters for acceptance seem quite wide, hence the variation in performance reports. 🙂

Just noticed my post count! 🥳

Triplet lens elements are very sensitive to lateral displacement and can cause all manner of optical effects. The decentring of the central spot despite adjusting the tilt of the cell was what made me suspect the issue. 🙂