mikeDnight

I don't go along with the often stated claim that the light grasp is halved. If you use a 6" telescope you will still get the full resolution of a 6" aperture, but with the added advantage of doubling your sensitivity to fine detail (the resolution remains that of a 6"), as you're using both your retinas. Neither is the light grasp halved! You will get the same light grasp of a 6" scope as light grasp is determined by the aperture. The binoviewer will divide the light recieved by the aperture and there will be some minimal light loss due to reflection on the prism surface, though anti reflection coatings greatly reduce such reflections. The light that enters the prism leaves the prism, that is why prism diagonals are so highly rated. On leaving the prisms the combined light is recieved by both retinas and the brain receives all the light from the combined light paths. So you are essentially using the full aperture of a 6" with the exception of very minimal loss at the prism. I use a 100mm refractor and objects like the Orion nebula, M13, M27 lose none of their wow factor, and are certainly not equal to a 2" or 3" aperture but still retain the full punch of the 4" apo.

Exactly what Stu says! Whatever jiggery pokery goes on in the binoviewer the brain puts back together again flawlessly. In fact I'd say there's a significant gain in the ease with which observable detail reveals itself, as both retina's are deciphering the information in the image rather than just one. So in a sense, by using a binoviewer, you are increasing the potential power of a telescope, not reducing it.

I bought a revelation binoviewer around ten or twelve years ago which cost me £99. It has performed admirably alongside much more expensive, and supposedly superior models, and I have no desire to "upgrade". Also, with the moon and planets through my 100mm apo, the binoviewer, 2X SW Delux barlow and paired cheap 16.8mm orthoscopics or plossl's out perform any and every high end single eyepiece that's ever been in side by side comparison. It's truly jaw dropping!

Baader Morpheus are superb and the 17.5mm will give you a spectacular high contrast view with a nice dark sky background.

If you haven't already tried using a binoviewer I'd suggest doing so at an astronomy club before buying one. Not everyone gets along with them! Personally I love them and would suggest you buy a cheap model, which are generally optically and mechanically very good. A 2X Delux Skywatcher barlow is excellent and will allow you to screw just the barlow lens element directly into your binoviewer, or use the full length barlow for a little more amplification. Don't waste money on expensive high end eyepieces for bino viewing. A good plossl or orthoscopic pair will deliver stunning lunar and planetary views that will equal the very best single planetary eyepieces in performance. Binoviewers are ok on brighter deep sky objects but generally they are best for moon and planets, where as deep sky is often better observed using a single quality wide field eyepiece.

I don't get too bogged down with the technicalities of eyepiece design but leave that to the experts. My comments are based entirely on personal experience. Eyepieces like the Abbe Orthoscopics were designed for use in telescopes having a long focal length, but today most telescopes are relatively short and so the Abbe Ortho design can struggle to give good correction at the edge of the field of view. More modern designs are much better at correcting the edge of the field, but this means more elements and greater expense. F11 is considered long by comparison to many of the refractors on offer today, but its short compared to the F15, F18 instruments and longer that were the general rule half a century ago. Some modern wide angle eyepieces can cost a small fortune, but for general use at F11 you could find some very nice performers in the Sky watcher range at a fraction of the price of many top brands.

I'm not a fan of Omni Plossl's, but find the TMB Planetary II to be quite a nice eyepiece. The original Burgess TMB Planetaries were the best if you can find any. The KSON Super Abbe Orthoscopics, though cheap, are excellent in scopes with long F ratio's. They are not so good at F11 unless you use a barlow. They also make great binoviewer pairs in the longer focal lengths. Personally I'd keep my eye out for second hand Japanese eyepieces such as the Vixen LV, Ultima 5 element super plossl's or volcanoe top orthoscopics. They are relatively cheap and often unappreciated, but they are top notch optically.

The SW 80ED is a nice scope but its in a large tube, same as the 100mm ED. If you could find a second hand Equinox 80ED then that would make a nice grab and go scope. However, a 102mm F7 ED is a much more impressive beast when it comes to rich star fields and nebulae. And its lunar and planetary prowess will wow you. I can see a love affair in the making!

Excellent sketch Mark. You've captured the Apple core shape perfectly, along with some subtle detail within it. It's a true eyepiece view you've managed to illustrate, which shows you're a very good and careful observer.

The detail in your image is breathtaking. Defnitely one of the best pics of M27 I've ever seen. Brilliant!

I'd forgot the DF and the DL have just two grub screws, where as the DC has three. There are shims inside the DC focuser as I found out after my dismantling escapade. I suppose adding another or adding slightly larger shims may help, which is something I hadn't considered. It might be that there will be some residual image shift but it should be pretty well controlled. With my own DC scope, I can use 300X with the target remaining in the centre of the field during focussing, so image shift isn't much of a problem, but I'm purely a visual observer and I may be less effected by it than others may be. Below is an image showing the three grub screws on the DC version.

She certainly looks gorgeous lying naked after her body waxing Dave. Makes my heart skip a beat!

I tried adjusting my DC focuser shortly after I bought the scope, as it was quite stiff. Using the three grub screws to adjust the tension I ended up making a bit of a mess of things, ending with very noticeable image shift. I phoned Nick Hudson at True Tech, who told me to remove the pinion, loosen off the three grub screws so the draw tube slides freely. Then he said to tighten each grub screw equally, counting the turns on each, until the draw tube friction moves smoothly. Then reassemble the pinion, gently tightening the two screws. It took me a couple of attempts, but the focuser image shift and the initial stiffness that prompted my intervention disappeared. I also attached the Tak micro focuser. It seems image shift is the result of the three grub screws being unevenly tightened!

I would rather go for a 6" F5 achromat as a rich field scope rather than a 6" F5 reflector. Having used several of them they've never failed to deliver stunningly sharp star fields, impressive light grasp, and are very comfortable to use. They make brilliant comet seekers! ☺

Imagine that. No experts ruining the planet! 😊 When are they all leaving?

I found the AZ5 acceptable for my 100mm F7.4 and it did carry the 100mm F9 reasonably well too, although it was at its limit. The SW AZ5 uses worm gears and not a tangent arm as with the AZ3. Also, the AZ5 allows easy observation from the horizon to the zenith without overbalancing or the clutches slipping. However, the SW AZ4 is better built and much stronger despite its lack of slow motion controls. I've used an AZ4 now for many years and love its simplicity and solidity. Like many mounts at the cheaper end of the market something's got to give, and with all of these mounts its the tripod, unless you opt for the steel version. My own AZ4 is mounted on an old but very solid Vixen aluminium tripod, and with the clutches properly set, I can observe at very high powers without fighting with the mount. Below is a pic of my 100mm F7.4 and my friends 100mm F9 both happily mounted on SW AZ4 mounts. ☺

It doubles as a bit of a man cave. Whenever the wife gets fed up with the repetitive banter between me and my friends, the observatory offers a clean and somewhat cosy retreat even in the cold of winter, as its electrically heated. And yes, it has been known to act as a dining room of sorts on occasion. 😊

The 4" apo will take higher powers than the Mak while maintaining a sharper star image, and so may prove to have the advantage in double star observing despite its smaller aperture. Again, when it comes to lunar and planetary, its sharpness will not be beaten by the Mak, with the apo sailing along at 300-400X on some targets, while the Mak would struggle to keep up. It stands to reason then that the advantage of a good apo on both stellar and lunar and planetary, then that would also translate when it comes to solar observing.Having said that, the 127mm Maksutov is a remarkably good scope, which in my view is probably the best out of the SW Mak range. The 127 is also a great portable scope. Whether you'd use the Mak much after buying an apo only time would tell.

So many wow's over 40years that I wouldn't know where to begin. What i would say though, is what I believe to be the biggest game changer for me over the last ten years, is the use of a cheap binoviewer. To see a pair of the cheapest Abbe orthoscopic eyepieces very noticeably outperform a single TMB Super Monocentric eyepiece was a real jaw dropping wow moment both for me and my friends.

It was my decision to down size slightly that prompted me to move to simpler, but still high quality eyepieces. I was very happy using my Equinox 120, but after buying a Equinox 80ED, I found myself using the 80mm far more often because of its ease of use and set-up. The 80ED was superb, especially with a binoviewer installed for lunar and planetary observing. At times it even gave a better view than the 120ED. So after considering the advantage of the smaller scope, I thought it would probably be a good move to go for a scope that was somewhere between the two, giving a little more resolution than the 80ED but retaining its light weight easy set-up. When I heard that Takahashi were offering a light weight 100mm fluorite apo, I couldn't resist and have never looked back. The 100DC is just as comfortable as a grab and go scope as it is as a great observatory instrument. Simplifying my eyepiece collection has also liberated several thousand pounds that had been trapped in a the form of Televue and Pentax eyepieces. In my FC100DC F7.4, my collection of excellent but old five element super plossls give me just as much joy with their piercingly sharp images. ☺

I know its a 80mm to 102mm under consideration, but perhaps the 120ED Pro should be thrown into the mix. They are no longer physically than the 102ED Pro and are terrific visual refractors!

An 80mm apo is a very enjoyable scope to use visually, but you'll notice a significant improvement in both brightness and detail through a 102mm apo. There's never been a better time to buy an apo refractor, particularly in the 80 to 100mm range. Whichever make you're thinking of, you'll be very unlikely to be disappointed. For some, an apochromatic refractor of around 4" aperture is all the scope they need. The second hand market has some gems at times, so you may not need to buy new!

I'm going to leave answering that apparently simple question to someone else John. As for the BAA. Definitely another thread! 😊

There's an almost endless banquet of telescopes available to the amateur today, and this may at times create some confusion for a newcomer to the hobby. So without going into all the intricate differences in designs and capabilities of every telescope, I was wondering what you would consider to be a "serious telescope"? For me, I've have some amazing times at the eyepiece of a 3" refractor and a 4.5" reflector, so on a personal level, I could play quite merrily with scopes of this aperture and not get fed up. Where does your heart lie and why?

What's imaging? Observing through the telescope is all i've ever done and almost certainly all I'll ever do. I'm fortunate to have a couple of excellent visual observers to associate with locally (good friends), so observing is very much alive and healthy in my little world. I do think the skill of observers is on the wane though, as many today just assume you need to either have a large aperture scope to see anything of worth, or you need to live on Hawaii - neither of which is true!