Split Zygote2

Dear mikeDnight, thank you for taking the time to pen this which I have just read with much interest. Reading between the lines on Roger Vine's site I had deduced some of it but it is good to hear matters first hand as it were. I totally echo your sentiments in respect of the SkyWatcher 120 EDs. My example shows no discernable colour either in or out of focus a trick my TV85 does not match and there is no perceptible glow of unfocussed light around the moon indicating a good level of polish. Of course mine is a very excellent example but then isn't everybody's? As a visual only scope it compares very well with the best, though photographically I suspect it would be a slightly different story. Horses for courses. I note your fondness for the AZ4, my Equinox 120 is mounted on one such atop a Berlebach tripod on wheels. Slightly vibration prone at high powers but still very usable and although I suspect the mount is at its limit here it is infinitely preferrable to my Ercole mount which exhibits way too much stiction in azimuth no matter how well balanced. Michael

A little late to the party (much sorrying) but for what it's worth... I have compared extensively a Tak TOA 130NFB to both a well collimated Skywatcher 10 inch Dob, flocked and fan cooled and a SkyWatcher Equinox 120. Three long nights in particular are worthy of report. First in respect of The Dobsonian - visual observation of the moon on a night of very good seeing at around 300x magnification the Tak just edged the Dobsonian in sharpness however on the following night of even better seeing The Dobsonian came out clearly as the victor. I have only been been observing seriously for around 6 years (although I bought my first Newtonian in the 1970s) but I have spent all too many hours in the darkroom testing photographic lenses and shooting many, many 1000s of frames to that end. To me the subjective difference between the dob and the Tak is very similar to comparing images taken with a Large Format Camera (negative size 5x4 inches) and a Medium Format Camera (negative size 6cm-ish x 7 cms) where the absolute sharpness of the lens (large format lenses are often not so sharp mine certainly were not) is not the only determinant of image quality. I suspect that the result of the first match between The Dobsonian (He insists on capitalisation) and the Tak illustrates the oft mentioned thought that a smaller apperture copes better with less than perfect seeing than a large one. In respect of the refractor shootout (SkyWatcher Equinox 120 vs. Tak TOA 130) on a night of truly superb seeing once again obseving the moon the Equinox (just aquired 2nd hand and I wanted to test it) reached 450x magnification before the image broke down while the Tak went on to 781x mag with no image breakdown at which point I had no shorter focal length eyepieces to use in the 2.5 powermate. Note I would not claim that this was a controlled test or representative of anything other than my experience of the two instruments concerned on one particular occasion. Such high powers are essentially empty magnification where no more detail is to be discerned and beside which the image is so very, very dim. Needless to say I was very pleased with the Equinox's performance which I bought as a roll it out onto the patio whilst praying, mostly in vain, for a break in the clouds sort of scope. Personally I am not predisposed to value something according to the price paid, rather the reverse. It has been my life experiance that if 999 units of exquisite perfection are produced the 1 in 1000 lemon will unerringly find its way to my door. I have for instance an early example of a TV 85 that I find quite underwhelming although this of course may not be entirely the scopes fault. Would I buy the Tak again? Well I bought it very hurriedly (I really wanted a TSA102) immediately after the Brexit vote as I feared (correctly) that the pound would be adversely affected. My thought was, "if not now - never." Optically it is very good. I have done the artificial star thing and the Ronchi grating thing and the electricity pylon thing (my favourite and shamefully my most observed target - to evaluate chromaric aberration) but while the 4 inch focuser displayed no image shift it would rack out abruptly under the weight of a 2 inch diagonal and an Ethos. (less than a kilo or so) with enough force to make a loud clunk or produce a yelp of pain if a finger was in the way when the scope was pointed down towards Australia. This issue thanks to the kind advice of the late Per Frejval (sp?) on this forum I have since rectified. Other than that the only thing I would note is that is it pretty heavy. 11 kilos or so sounds manageable but this becomes 14.5 kilos with tube rings diagonals et al. Add 3 kilos of scuba diving weights at the focuser end to raise the eyepiece higher when pointed towards the zenith and mounting the scope becomes an exercise that requires planning, practise, a good back and much care. Changing equipment for me is often precipitated by the thought that "The grass is greener on the other side" which is then tempered by an oft voiced regret "Why, oh why did I ever sell that scope!" I suspect that I am not unique in this, all I can say in conclusion is that in respect of the TOA 130 I have no desire to scratch this particular itch. Michael

Thank you Ron for your comments and thank you Cornelius for your imput. Michael

A little long - sorry! This cord wrap issue may (or may not) happen to someone else and result in a less fortunate outcome. AND apologies if this is already a well known foible of the equipment in question - I did do a search with a negative result. Formatting may be a little weird as I did a copy and paste from a word programme but see point 3 below! Disclosure: firstly, the mount - it is BLAMELESS (a statement of faith; we have bonded!) secondly, what happed may on the one hand be the result of a unique set of circumstances that will not occur again before the end of time, yet on the other hand....... thirdly, I am a Board Certified Muppet (Eldest Child's Opinion and possibly not wrong) - when anything related to computers or software is involved. Computers just know when you don't like 'em! The mount (a mid 2016 example) was very recently upgraded by obtaining the SkyWatcher SynScan WiFi module, the SynScan App (Pro 1.11.3) which I run on an iPad Air (the first one) using iOS 12.0.1. This was connected to the dongle(?) generated WiFi to control the mount. I have used this set up for a few nights without incident. I had set up outside on the patio and the mount was slowly tracking across some trees at a sidereal rate (it was daytime) as I was occupied in balancing some new equipment. The Wi-Fi module was plugged in, the mount in Alt-Az mode was being controlled by the iPad using the SynScan App alone (i.e. no planetarium programme or any other device was involved); power as usual was supplied by a fully charged Tracer LiFePO4 12V 16 Ah battery which typically supplies according to my meter around 14 volts over a 2 metre length of cable. All was well, however at this point my brother phoned to query some points in an e-mail that I had sent him. Leaving the mount to do its own thing I went into the lounge via the French Doors, taking the iPad with me, sat on the sofa and loaded up the mail programme to review the mail in question - this doesn't require an internet connection. It is unclear whether or not I shut down the Syn-Scan App (probably not) and I do not know at this point whether the iPad reverted to the Home Wi-Fi network (still on auto join) or stayed connected to the mount's. I suspect it stayed paired with the mount as the mount was much nearer and that is what it had always done before. After a short while on the sofa talking to my brother I became aware of a noise that sounded like a cross between a stationary, hovering camera drone and an angry hornet. The noise was strangely persistent and unchanging in character - so I idly walked outside to investigate. The AZ EQ6 was in distress, not moving and with the power plug bent to an unnatural angle as the motor strained against the power lead which was tightly wound several times around the mount. In addition my TeleVue 85 had seemingly been doing a fair imitation of a propeller as while it was currently motionless and horizontal it was upside down (very fortunately not hitting anything in the process). I cut the power released the clutches and manually untangled the cable. The plastic plug insert inside the metal plug housing screwing the power cable to the mount had fractured neatly into two (possibly by design) but otherwise based on subsequent testing the mount would appear as yet to be undamaged. It could have been a lot worse. In previous instances of briefly, absentmindedly and unintentionally exiting but not shutting down the Syn-Scan App nothing dramatic has occurred. Evidently on this occasion, in these circumstances and given the short amount of time that I was away from the mount, the mount seems to have moved at full slewing speed 'til it could go no more however hard it tried - I would estimate based on the cable wrap 2 full revolutions or so - at the time I wasn't counting . As far as I am aware in a normal Go-To (and the mount was not left going to anywhere it was just left tracking) the mount obeys its software limits to prevent cable wrap (at least using the SynScan hand controller v4.something) and to intentionally recreate this situation I guess you would have to manually hold down the slew control until full cable wrap was achieved; self evidently I was not doing this. Whatever (a word I thought I would never use thus), IT DID NOT FAIL SAFE. The lesson learned is to maybe Hibernate (the App speak for Park) the mount if multitasking with the iPad, better still not to multitask or if unavoidable to stay with the mount. At the moment and without further experience I would be reluctant to again leave the mount to its own devices when using this set up for control. The mount is in regular use carrying a heavy scope that requires 20 kilos of counterweight - had this been the case on this occasion it might have cost very much more than a new power lead. Any thoughts or opinions would be welcome. Our nearest neighbours are SHEEP and although noisy on occasion I feel that they are unlikely to generate much in the way of RF interference. Thank you.

Hi - I have just got a 10 inch Dobsonian having recently moved to a relatively dark sky. I have been interested in astronomy for many, many years and have read a lot but up till now have not done any real observing - so pretty much clueless in terms of finding my way around the sky. I have installed an azimuth protractor on my Dob,changed the azimuth bearings and purchased a digital inclinometer so that with RDF and Stellarium when/if the clouds clear I should be in business. A big thank you to this site which I have perused often already! AstroBaby's Collimation advice in particular has been invaluable; my secondary mirror will be forever in her debt - everybody seems very willing to share their no doubt hard won expertise.