mikeDnight

What about an 'armchair astronomer' chair, for those wild winter nights when us oldies choose a good old classic fireside read rather than freezing to death. ☺ Does this count?

Hi Rob, That's the main reason I don't like the Sytee mount. It's trying to be all things, when very often, the main reason for a mount like that is simplicity. Plus I think it spoils the look.

That's mighty kind of you Paul. You're a good mate, and I don't care what everyone else says! The Vixen won't need a tripod as I'd use the one I already have, and there's already a counterweight attached to it. I really hate Altaz mounts that need counterweight arms to balance a scope. The DZ won't really need a balancing arm as it weighs next to nowt. With the Vixen AZ the counterweight sits tight against the mount body. It's a shame no one makes a proper altazimuth fork mount with slow motions anymore. The only other Altaz's are the Losmandy AZ8 and the Rowan, both of which are overkill for my scope. The Losmandy is all in and works straight off, but with the Rowan you've to pay through the nose to get essential extras to make the darn thing work. It's like buying a car and having to buy the wheels and seats seperately. A T-Rex would be far better for me but sadly nolonger available, and John won't sell me his for less than six figures.LOL I don't actually need a new Altaz, or anything else for that matter. I'm just window shopping due to lockdown boredom!

That's a great report and experience Gerry. The Moon really is utterly spectacular when viewed through a binoviewer, even in a small scope. Your 15" sounds like an amazing beast though, and I had a mental picture of your TSA stood shivering on the side line, like the skinny wet kid at the edge of a swimming pool, waiting for his dad to help him get dry. Poor thing! Didn't you feel just a little guilty? 😁

Then at the cheaper end of the market, there's the Skywatcher Delux 2X Barlow, which is remarkably good even in a Tak FC100D. I currently use an old Celestron Ultima SV Barlow in my FC100DZ when I use my binoviewer, and there's no hint of CA. The SW Delux is equally colour free in the binoviewer too. The Delux certainly won't break the bank, and although the Celestron Ultima SV is nolonger in production, it can still be found second hand for around £45 to £50. Takahashi offer a 2X barlow that goes before the diagonal, but in all honesty, I found it no better than the SW Delux or Ultima SV. If you want to use a truly top class amplifier, Then buy yourself a Takahashi 1.6X extender-Q. You could even combine the Q with a 2X barlow to really boost your power when the seeing allows.

I'm wondering if anyone has had hands on experience of this mount? It seems to be a good size and strength for a grab and go altaz', but it is quite pricey for a small to mid range mount. I'm particularly interested in the amount of plastic in the form of covers and caps that could crack or get easily damaged over time. At the price, I would prefer no plastic at all, but that could be a big ask.

If adjusting the screws doesn't solve the problem, you could try gently tightening the nut that holds the worm, shown at the top left of your pic. I've come across several old mounts displaying slack, but by simply tightening the above nut it prevents the worm from any sideways movement, and the mount then drives perfectly.

"Open window" isnt good! The orthoscopics probably appeared to perform well because of their lower magnification, where as the TOE at 4mm would be magnifying the heat currents washing out the Pop. Tak ortho's and a TOE - I'm a little envious!

Can I ask what eyepiece you were using? I'm just wondering if the eyepiece had a smallish eye lens, its possible that some moisture or oil from an eyelash could have transfered onto the lens? It's strange that moving your eye over the eyepiece changed the view.

We're the scopes mounted piggy back on an equatorial or on an altazimuth? And could the Tak have been closer to the tree tops? Trees can cause problems at times, even if they aren't actually covering the object being viewed. My western horizon has a high tree line that disturbs the view of an object as it nears the tree tops. Also, could there be air vents in your neighbours roof that may allow heat to roll up the roof?

Hi Alan, First off, its almost certainly nothing to do with your scope, either mechanically or optically, and almost certainly due to some form of atmospheric disturbance. A similar thing has happened to me a couple of times. The first was back in 2003 just after I'd bought a brand new FS128. I'd taken my scope excitedly round to my friends house where we had first light with a view of Jupiter. It was absolute perfection, and the Galilean satellites were perfect tiny discs each subtly different in colour and size. Then I swung the scope round to look at Vega in the east. The star image was terrible! It wasn't boiling or colourful, but just a stationary blur. I was distraught, as I'd paid £3,850,00 for this scope and I was far from rich. I arranged for the scope to go back to the vendor but the currier didn't turn up. So I decided to take the FS to my local astronomy club to get some moral support. That was a mistake! As i walked up the hilll towards the big observatory, my so called friends were all hysterical with laughter and rolling round on the grass desperately trying to grab their breath. My friend Gain tried calmly to reassure me saying "Michael - Takahashi don't make bad scopes"! At the same time my other friend Paul had tears streaming down his face and was almost wetting himself. Then Peter Drew took the scope off me, mounted it on a GP, and aimed it at Vega. After a few seconds Peter stepped back from the telescope and said "That's one of the best star images I've seen". I looked and saw a perfect image of Vega. Then I tried to explain that it wasn't like that two days earlier, but they just looked at me as though I was nuts. The FS never gave a bad image after that first view of Vega. The second time this happened was in April 2017. The night was one of exceptionally good seeing and the first quarter Moon was high in the sky. My friends Paul and Rodger had called round to observe with me. I was using my FC100DC and Paul brought his FC100DL. Both scopes performed perfectly and we all observed together for several hours. Rodger was amazed at how well colour corrected the DC was. As Jupiter rose in the east we aimed both scopes at the planet. Both scopes were pretty much on an equal footing, until suddenly the DC gave the same stationary blur that I'd seen on Jupiter all those years earlier. Detail on Jupiter's disc all but disappeared in the DC, which was mounted on my GP in my observatory. Paul's DL was around twenty feet further down the garden and gave a spectacular view of the festoons, garlands and white ovals. At first I wondered If the lens had dewed over, but it was as clear as crystal. Looking at the situation the following day, I noted the DC had been looking directly over the apex of a bungalow a few yards away. The DL however looked past the house. The atmosphere on both occasions was steady, so any mild heat plume would rise like a steady column. I can only imagine such a steady mild heat plume to be the only reason possible for creating that steady blur. The FS and DC were capable of extreme high power, which they wouldn't have been if the optics weren't top class. May be in your case, one scope was looking through a stable heat column while the other wasn't? My friend Gain posing with my FS128 mounted on the Astronomy Centre's GP mount, spring 2003. below, my glorious FC100DC on its GP mount in my observatory, spring 2017.

I spent an hour looking at stars and a few fuzzies with my DZ after the clouds cleared last night, and the need to understand Takahashi diagrams suddenly became unimportant. The seeing was ok but certainly not steady, and there was a haziness all around. M42 was dropping low behind the tree line towards my south west, yet the E star was instantly obvious with the scope straight out of the house. I couldn't make out the F star, but the trees were in the way. The soot black nebulosity in M42 stood out solidly against the brighter nebula. It was a glorious sight made all the more impressive given the poor position of Orion. I played around with various eyepieces for a while, enjoying the views of rich star fields and open clusters. The Pleiades, despite being low was still enmeshed in subtle nebulosity. But the most pleasurable and memorable part of the evening were the stars themselves. Despite the less than perfect seeing the star images were simply exquisite, and the little DZ with a 2mm Vixen HR eyepiece stood 400X with ease, it wasn't even breaking into a sweat, and still it gave textbook images. I also found that eyepiece choice makes a real difference. The HR's are a perfect match with the DZ and double stars, and my old Ultrascopic's kept pace quite well in giving perfect star images. But quite surprisingly, my 10XW compared to my 10mm Ultrascopic, was not quite upto delivering the sharpest stars, even on axis. It is still a beautiful eyepiece though, but perhaps nolonger good enough!? So it seems you don't need to worry about graphs, you just need to look at the stars.

The 120mm Evostar (Helios as it was called back in 1999), was not a particularly heavy telescope. And the EQ 3 that came with it was certainly adequat enough to carry the scope to allow for serious prolonged observing. If you intend to carry this set-up any distance, then unless the tripod or engineering has changed since then, it should work well. Heavier mounts and heavier counterweights may mean the scope gets used less.

Hi Chris, I talked a friend into buying one of these chinese 4" achromats back in 1999, so I could check it out. It was so good that the following day I ordered a 120mm F8.3. The 120mm came on an EQ3 which was adequate for carrying the tube assembly. It came with three very nice silver-top plossl eyepieces and a good diagonal and 2X barlow. The first view through it was of a crescent Moon, and I was very pleased at the colour correction. In fact my first thoughts were "where is the false colour?" The view was sharp and pleasing, and the 120mm aperture made the scope good for observing brighter deep sky objects. If all I had today was that 120mm scope, I would still be having a great time observing.

Wow - I'm in awe of your Vulcan logic Jeremy. No wonder you're a doctor!

I like the colours! Other than that, for a purely visual observer such as myself, the graphs don't really tell me much. Neither the two TSA's, one FC100DC, two DL's or one DZ that I've observed with showed any hint of visible CA.

I was just seeing who was paying attention. ☺ Takahashi's claim, not mine!

The 40mm Pentax XW is a very nice eyepiece. The 30mm may be better though, as with a 40mm the sky background tends to be too bright, and nebulous objects not so easy to see. The 30mm XW or 31mm Nagler are two of the best I've used. The 40mm Paragon lost it towards the edge slightly.

I don't believe anyone said fluorite was hundreds of times better than FPL53, but it is better. I've never seen any fluorite lens, that's been handled with the usual care of any refractor, shatter. If you ever fancy dropping a crown & flint objective against a hard surface, you'll find the flint element will be just as prone to shatter or flake. It does take more care to form, grind, polish and figure fluorite, hence the greater cost, but Takahashi, Canon Optron and numerous others must think its well worth the effort, otherwise they'ed take the easier option. Really, if fluorite was such a fragile material, no one would use it or want it. And this would extend into the camera and telephoto lens community too, where telephoto lenses can cause the cost of a fluorite telescope to pale into insignificance. Fluorite is not a miracle material, but it does allow a doublet to perform like a top class triplet. Fluorite lenses also allow for brighter images than other glasses. The use of fluorite isn't marketing nonsense but simply a high quality material alternative that has several advantages over other glass types.

According to Takahashi, Fluorite is "many orders of magnitude better than any ED glass." Whatever that means. Laboratory grown Fluorite crystal is also just as tough as many other optical glasses. The hydrophobic nature of fluorite is grossly over emphasized by some, and is generally more applicable to naturally occuring fluorite. I once placed two pieces of naturall fluorite in a sealed container full of water, and after draining the water away around six months later, they appeared to be totally unchanged. The specimens certainly hadn't broken down or turned to jelly. Plus, modern fluorite lenses made by the likes of Takahashi are hard multi coated, and even the old early FC's and Vixen FL102's that had uncoated fluorite elements are still going strong four decades later.

Vixen HR's and Takahashi TOE's are very short focal length with superb sharpness, clarity and definition.

It would depend on who made the fluorite doublet and FPL53 triplet. Merely being made of fluorite or FPL53, doublet or triplet is no guarantee of performance. And there's much more to a scope than colour correction. If the over all optical figure is high, then that's the scope that will perform best, even if its an achromat.

I feel there's a really noticeable jump from 4" to 5", but not such a noticeable jump from 5" to 6". Light grasp will be the most obvious improvement, and if the lens figure is really good, the scope should have an advantage in planetary performance too.

A friend of mine bought a Meade 127 triplet that I'm pretty sure used FPL51. This was quite some time ago and I hate anything with the Meade label on it. Honestly, that scope was as colour free (visually) as any apo I've ever used. I suspect the Tecnosky 152 triplet will be as good if not better as a visual scope. When mated with the right elements a FPL53 triplet can be a beautiful apo.

Hi Phil. The Tecnosky 125mm doublet ED apo is currently being discussed in the scopes forum. It looks gorgeous and is well within your budget. The Skywatcher 120mm or 100mm ED is another you might like to consider. Eyepiece such as Baader Hyperion's or Baader Morpheus are really excellent, as are any of the Baader diagonals. Personally I'd keep my mount choice low tech, as its easy to eat into your budget once you go down the go-to route. A simple Altazimuth or basic EQ5 equatorial style mount would be adequate, and would allow you to invest more in the scope itself.