johnturley

Out of curiosity, how did you find the TSA 120, compared to the FS 128. John

Would be interested to see what you think of this mount, I was thinking of getting one as a lighter alternative to my AZ-EQ5 mount. The latter was bought to accommodate my ES 127mm Refractor, however the Star Adventurer GTi would probably be adequate for my recently acquired Tak 100 DZ. John

Totally cloudy here. John

Observed Jupiter after 5pm last night through my 14in Newtonian and Esprit 150 in time for the Great Red Spot transit, viewing conditions were reasonable, but not great., limiting the usable magnification to around 160x through both instruments. I was however able to make out the GRS through both instruments, the view through the Esprit was sharper (as usual), but the colour of GRS stood out more through the larger Newtonian. I looked again at around 7 pm, but surprisingly perhaps, viewing conditions had significantly deteriorated. I then looked for the 2 comets which should have been on view, Pons Brooks in Cygnus, and P Kushida in Taurus, but was unable to spot either comet. P Kushida was always going to be difficult in my Bortle 5 skies at around magnitude +10 (fainter than predicted in the ephemeris), but I did expect to spot Pons-Brooks, which should have been around +8.5, similar in magnitude to the Ring Nebula in Lyra, which I usually find quite easy to spot. However Pons-Brooks was quite low down by then, and the lights were still on at the nearby school (they go out later in the evening), causing the sky to be brighter than normal. I finally took a quick look at Uranus which showed up as a pale greenish-blue disc, as with the GRS, the colour was more obvious through the 14in Newtonian. John

I don't know why current telescope manufacturers don't offer 'Slip Bands' with their scopes as Fullerscopes used to do in the 1970's. John

At one time Pluto was thought to be an escaped moon of Neptune, and its 'escape' was supposed to be what caused Triton to circle Neptune retrograde, however I don't think that theory is in favour anymore. John

Interestingly I understand Clyde Tombaugh tracked down Pluto in 1930, based on predictions by Percival Lowell which were based on the gravitational impact of the suspected Planet 9 on the orbits of Uranus and Neptune. In fact it had actually been imaged 15 years earlier in 1915, but missed apparently because one image fell on a flaw in the photographic plate, and in the other it was too close to a brighter star to be identified. According to Percival Lowell's calculations, to have these impacts Planet 9 should have a mass similar to that of the earth, and a diameter of around 8,000 miles. Following observations with the then new 200in Palomar Telescope, the diameter of Pluto was revised down from 8,000 to 3,600 miles, and following later observations from spacecraft and the Hubble Space Telescope was then revised down further to only 1,400 miles, less than half the size of Mercury, and smaller than the Earth's moon, and less than 1% of the earth's mass, so it couldn't have had the gravitational impacts that supposedly led to its discovery. This therefore leaves a bit of a mystery as to how Pluto was tracked down in the first place, and its discovery close to the predicted position is now put down to being a bit of coincidence. John

I suppose if depends on the reflectivity of your curtains, most curtains will have a higher reflectivity than plain glass (except perhaps in the matt black curtains), so it will probably get darker in the bedroom when the curtains are opened. John

That's for the Edge HD version, the standard XLT version is £1,895. John

According to the map, I'm quite well placed away from most of the main flight paths in Dronfield, Derbyshire. John

Sounds like I was never going to get the best results from my C9.25 with storing it in the conservatory (which can get quite warm in sunny weather even in winter), and then bringing it out just before use. My Tak 100 DZ, which is stored in the same place, will cool down and acclimatise much more quickly. My Esprit 150 is stored in a wooden observatory shed (piggybacked on my 14in Newtonian) where the temperature will be much closer to the ambient, although it can get quite warm in summer. The need for the C9.25 substantially diminished anyway after I purchased the Esprit 150, although it would have been potentially better for planetary photography, having more than double the focal length. John

My C9.25 gave quite good results on planets, although I don't think it was as sharp as the Esprit 150, but unfortunately I never got round to comparing them side by side, partly because my wife had 'boxed it in' in the conservatory with some quite large house plants. Sounds like you were unfortunate by getting a bad sample with your C9.25, some claimed that the C9.25 provided superior planetary views even compared to the C11, because of the longer (f2.5) focal ratio of the primary compared to the C8 and C11. Did you check the collimation, Rother Valley Optics checked mine before I purchased it. John

That's interesting as some observers regard Mewlons as being 'Planet Killers', however, especially since getting my Esprit 150, I've become more of a refractor enthusiast, and to me the ultimate Planet Killer if one could afford to buy and accommodate it, would be a TEC 200 or perhaps even a TEC 250. John

My original post was asking the question as to whether a Takahashi 100 DZ could outperform a Non Premium 120- 127 mm Refractor, such as my Explore Scientific 127mm FCD 100 Refractor, and based on the comparisons I have carried out so far, the answer appears to be one of ‘Yes, Maybe, but only Just’. Last week (16th– 18th January), taking advantage of the cold clear conditions, I mounted both instruments on my Skywatcher AZ-EQ5 Mount in AZ mode (see photo), and compared the view of the Moon and Jupiter, through both scopes. It was not possible to get the two scopes exactly aligned to each other (the AZ-EQ5 has fine adjustments in altitude but not in azimuth), but managed it within a couple of degrees. I also on 16th and 17th January, compared the view with that through my Esprit 150, which is piggybacked on my 14in Newtonian in my observatory shed, and which can be seen to the right in the attached photo. In order to get the magnifications as close together as possible, I employed a 4.7mm ES 82 degree eyepiece in the Tak, a 5.5mm ES 62 degree eyepiece (which is a sharp little eyepiece) in ES 127, and a 7mm T6 Nagler in the Esprit 150, giving magnifications of 170x, 174x, and 150x respectively. I did try on one occasion a 3.5mm T6 Nagler giving 228x in the Tak, but viewing conditions weren’t good enough to support this magnification. On 16 Jan in particular I compared visibility of craterlets within the Mare Crisium on the Moon, on 17 Jan the shadow transit of Europa on Jupiter, and on 18 January the Alpine Valley on the Moon. As expected, with its extra 27mm of aperture the ES 127 gave a brighter view, but the view through the 100 DZ appeared generally sharper, but only marginally so. One advantage maybe in the Tak's favour was that with it, I was using a Baader Zeiss Prism Diagonal, as opposed to a Baader 2in Dielectric Diagonal with the ES 127, and a 2in BBHS Diagonal with the Esprit. However the view through the Esprit 150, was significantly sharper and brighter than the other two instruments, I have compared the Esprit 150 with the ES127 on previous occasions, and thought that the advantage to the Esprit was greater than might be expected from just the extra 23mm of aperture. Unfortunately I never got round to comparing my 9.25 CPC before I sold it with the Esprit 150, but I suspect that at least as far as sharpness was concerned, the advantage would have been with the Esprit, except perhaps under very good viewing conditions. The CPC however could give good planetary views, so I’m really surprised when @Mr Spockstated in another thread that his Tak 100DF consistently outperformed his C9.25 on Jupiter. I haven’t so far done a comparison between 100DZ and the ES 127 when it comes to faint Deep Sky Objects, but with its extra 27 mm of aperture, I would expect the advantage to be ES 127 The outstanding thing about the Tak 100DZ however, is how light and portable it is compared to the ES127, and does pack good performance into a relatively small light package. One of the reasons I decided to purchase one, was that due to recent back problems I wanted a lighter and more portable scope, so as to reach areas of the sky which are obstructed from my observatory shed, and possibly also to take on holiday, so I don’t regret purchasing it. I may also consider a smaller lighter mount than my AZ-EQ5 (which was purchased to accommodate the ES 127), but it’s not too heavy to carry round, especially with just one counterweight, which is all that is needed with the 100 DZ To summarise, based on my experience with my 100 DZ so far, Taks are optically very high quality scopes, but they do perform according to the Laws of Physics, and not the Laws of Magic, as some Tak enthusiasts suggest, permitting much higher magnifications (up to 100x or even 120x per inch of aperture) to be used compared to other scopes. I can’t see ever being able to use 400x to advantage on planets (maybe on double stars) through my 100DZ. It would be interesting to compare the performance of a 100mm Tak with scopes such as the StellaMira 125mm ED Doublet, or Esprit 120 (similar price point). It may well be that the optical quality of Taks is more consistent than with most other makes, although Es Reid informed me that he has occasionally come across what he described as a Friday afternoon Tak, which is one reason why I went for the Zygo Test from Rother Valley Optics for my 100 DZ. I may be fortunate in so much as according to Es Reid, my Esprit was one of the best he had tested, he had in his workshop at the same time a Tak FS 152 for renovation, which he said my Esprit compared favorably to. John

Yes, it does, it's only about half the size it was in the 1970's, when it was easier to spot. John

I'm really surprised to hear about your experience with a C 9.25, I had a C 9.25 (CPC version) for nearly 10 years also. I bought it to provide me with something slightly portable, as at the time I was planning to move house, and didn't know whether I would be able to move my observatory shed which contains my 14in Newtonian. In addition at the time, the C9.25 had a reputation for providing superior planetary views due in part to the longer (f2.5) focal ratio of the primary mirror compared to the C8 and the C11. The house move however did not materialise, as I ended up splitting up with my then girlfriend, but I did compare the C9.25 on a number of occasions with my 14in Newtonian, and found that it gave quite good planetary performance, and depending on viewing conditions, it sometimes gave a steadier view than the 14in. Regrettably I never got round to to comparing the CPC 9.25 with my Esprit 150 after I purchased the latter in 2019, although it had been my intention to do so, partly because my present wife had 'boxed it in' a corner of the conservatory with some large house plants. Following back problems last year, I decided I wanted something lighter and more portable (with hindsight I think would have done better buying a C9.25 OTA and mount separately rather than the CPC version), and sold the CPC 9.25 to part fund the purchase of my Tak 100 DZ, which when finally blessed with clear skies over the last few days, I have been comparing with both my Explore Scientific 127mm, and Esprit 150 Refractors. I will give further details in another thread, but looking at the Moon and Jupiter over the last few days, I have been finding that 100DZ and ES 127 gave similar performance, but that the view through the 100 DZ, although less bright (due to the smaller aperture) appeared slightly sharper. Nether instrument however came close to the view through the Esprit 150, which on most nights equals, or gives a more pleasing view on planets than the 14in Newtonian. I realise however that an Esprit 150 would be far too big and heavy (plus expensive) for the OP to consider, but maybe something like the APM 140 FPL53 doublet, which at about 9kg is a similar weight to the C9.25, might be worth considering. John

It doesn't have to be GOTO, mine isn't, but ideally you need be able to position the scope correctly straight away, so that it is initially within the field of view of your favourite low power eyepiece without having to 'sweep around'. Another key to making it easier to find, is leaving the focusing mount in the correct focal position for your favourite low power wide field eyepiece, its a lot a harder to find if you have to re-focus first. I initially use a TV 24mm Panoptic, which is parfocal with my T6 Naglers, if you have to refocus after changing to a higher power eyepiece you can easily end up 'losing it'. John

I can usually find Mercury in daylight using a combination of a setting circles and a sidereal clock (actually an app on phone these days), provided the magnitude is brighter than zero, it helps if the sun is down below buildings or other obstructions making the sky background appear less bright. Between zero and +1 finding it becomes increasingly more difficult, and I don't even both trying if it is fainter than +1. John

Arrived yesterday from 365 Astronomy (FLO were out of stock) a Baader Zeiss T2 Thread Prism Diagonal, and from FLO to fit the diagonal a Baader T2 1.25in Helical Focuser, and a T2 to 2in Nosepiece. According to some observers, the Baader Zeiss Prism Diagonal should give better better high power lunar and planetary views through my Tak 100 DZ than my Baader 2in Dielectric Star Diagonal, and I bought the Helical Focuser as an alternative to fitting a micro focuser to the Tak, which I've read mixed reports about. I didn't want to go to the expense of fitting a Feathertouch Ficuser, and one disadvantage of the helical focuser is that it only takes 1.25in eyepieces, but with the Baader Click-Lock accessories I have fitted, it is easy to swap to my 2in Diagonal if I want to use 2in eyepieces.

According to the information on Astro Trail's website (UK Tour Organiser), the likelihood of clear skies in the Torreon area of Northern Mexico, is greater than for most locations in the USA, but who knows. Mexico / USA Total Solar Eclipse 2024 | Astro Trails (astro-trails.com) John

Cloudy here in Derbyshire too, as it has been for the last few days, but forecast to improve over the next few days. John

I take it that's the Baader T2 Zeiss Prism Diagonal, I've just ordered one for my Tak 100 DZ from 365 Astronomy who had it in stock, FLO are currently out of stock, and advised me that they are not expecting fresh stock until around April-June time. John

Hi Louise Thanks for your postings, we are on return flight BA 242 with British Airways on 18 April, I have sent you a Private Message. John

I take it then you are not very happy with your Orion Optics 10in Dob, what's wrong with it. John

With my 14in Newtonian (on which my Esprit 150 is piggybacked), I use old fashioned setting circles and a sidereal clock (actually an app on my phone these days). It's on a massive fork mount built by Astro Systems (Luton) in the 1980's, but because of its age it's not GOTO, just mains synchronous motor with variable frequency oscillator. It would be nice to upgrade the mount to GOTO, but because of its design, it would probably cost a fortune to do so, if it was even possible. John