mikeDnight

I think paulastro has the original version of the Astro Tech 102ED. I've used it numerous times and the one thing that strikes me when thinking about it, is that nothing strikes me! In other words, if the CA were objectionable I would definitely have noticed it. If the star images were anything but perfect it would have jumped out like a sore thumb. And if its lunar and planetary performance was In anyway lacking, I would definitely have noticed it! Consider also that Paul's scope had its focuser replaced with a feathertouch by its original owner. It must have been very highly thought of as noone would go to that expense for a mediocre scope. Also, Paul regularly observes with me using his AT ED alongside my Tak FC100DC and the two scopes get along fine. There is no rivalry between the two and they play pretty on all targets. I think a 4" ED is an excellent scope for a serious observer who likes a portable, easy to use, yet very capable all round wide field/lunar/planetary/binary star instrument. Often excelling well beyond their aperture class, a 4" refractor could be the only scope you'll ever need! Whether its the only scope you'll ever want is another matter! Just a quick point on glass types. Years ago manufacturer's didn't necessarily disclose the glass type used in their scopes. I've used a few old Vixen ED's long and short and they were all superb! Today it seems everyone worries a little too much about things they really don't need to worry about. Strehl for example: could anyone really tell the difference between a strehl of say .97 and .99? What i do know is that if you want to add colour to a refractor image, use a Nagler eyepiece and look at the Moon. I wonder how many good apo's have received bad press that way?

FC100DC ready for some lunar observing. FS152 looking at Venus FS128 on a field trip to the Astronomy Centre Todmorden. FC100DC getting ready for bed after a night with the Moon. 150mm Helios F8 refractor FS128 alongside SW Star Travel 102, along with Mike and son Daniel, along with Floppy Bear, on a field trip to Huddersfield Astro Societie's Transit of Venus event in 2004.

A good diagonal won't degrade the image though, as if they did, no one would use them. Also, turning a refractor into a catadioptric by the use of a diagonal is like saying a reflector becomes a refractor by the use of an eyepiece. The mirror or prism only redirects the light, it doesn't play an integral part in forming the image as a corrector plate or meniscus lens would in a true cat'. It's generally felt that mirrors work best in fast F ratio scopes and that may be true, but a friend of mine uses a Tak prism in his Sky 90 without any noticeable degradation in image quality. You could perhaps find an old circle T prism, which are excellent, and try it out. Some cheap prisms though can be atrocious. I had to atomise at least two Celestron prisms because they delivered putrid images. But cheap mirrors can be equally as bad.

Here's a blast from the past! Still all in good working order and nice to use on my 60mm Astral, as they give that vintage view that was good enough to set many of us on a lifetime adventure.

Ooh! This seems overly complex! Not in its actual complexity but in its necessity. I've seen statistics and I've seen dark sky charts and don't really find them to be of much value. Dark sky charts for example show my site to be questionable. The reality is that I get some excellent seeing, and on occasion some great transparency. I can easily see M31 with the naked eye and on transparent nights mag 6 at the zenith. The milkyway is generally visible from my garden on pretty much any clear night. I don't really worry myself about what my site is determined to be by any source other than what I personally experience. Sometimes, thinking too long on the negatives can negatively affect our joy. The thing that bothers me most are aircraft vapour trails, which utterly destroy good seeing and transparency. I can't wait for the next Icelandic volcano to erupt and those monstrous flying polluting machines get grounded again!

I'm enthusiastic about your future review John, but I'm in no rush to read about it. If your location is anything like mine, early spring time seems to offer consistently excellent conditions. With the moon high in the sky and a steady transparent atmosphere, some high power high definition viewing should be achievable, and it still gets dark early enough to offer great views of dso's. It might be worth holding onto it for a while! If the views through the 120ED are anything to go by the 150ED should be a very capable and enjoyable scope to use. And as much as I like Takahashi, no 150mm Tak is going to offer £10,000.00 worth more in performance. This should be a review well worth patiently waiting for!

Hi Cleetus, I have a large privet hedge that surrounds my garden, and where I live there's a large park, plus woodlands and fields to my west and north extending for miles, so lots of grass etc. It's probably the privet hedge though that's the real problem. The dew spots are only minor and the FC lens has never completely sewed over. My larger refractors in the past all dewed over quite regularly, possibly due to me living close to a river.

Bought in March 2015, I've cleaned my objective three times, getting rid of pollen and dew spots. Happily the coatings haven't slid off or been wiped off, and the lens still looks immaculate thanks to my trusty Caloclean - Solvent free - optical lens cleaning spray and cleaning cloth.

Tak have definitely removed the alcohol warning so perhaps it was a mistranslation after all!? Below is the original info from page 19 of the user manual.

There is no doubt in my mind that the feathertouch is far superior to the Tak focuser, but it is pricey. Having said that, the Tak microfocuser isn't that cheap either, but I've found it more than adequate for my own needs. If I ever had the spare funds I would definitely consider a feathertouch replacement, as the telescope itself is definitely worth it.

Trial and error works for me!

Yes, it seems to be 81 that might be throwing your focus too far out. 15 should screw directly onto the draw tube and all should be well. I don't know why Takahashi insist on supplying these adapters. I'm sure it would be simpler and cheaper to just have a longer draw tube.

Did you have the extension tubes attached? If so, you'll need to remove them. The set-up should look like the attached picture when a diagonal is used. In this mode the scope should focus pretty much all 1.25" eyepieces. You might like to try and focus on the distant horizon before you aim it at the night sky, at least until you've acquired a finderscope of some sort. It's interesting that you say the latest user manual makes no mention of alcohol! Great scope by the way!!

Yo may be able to order the paint from Nick Hudson at True Technology if the worst ever happened. Hopefully it never will!

I'm not sure how the red dot finders attach to a scope normally, but if they do so by a small dovetail adapter, you could perhaps attach one to the flat surface of your clam shell. By removing the screw protruding from the top of the clam shell you could possibly attach a finder shoe to the shell. If screwing inward from the top of the clam shell be careful that the screw isn't too long or it will scratch that beautiful paintwork.

It's a difficult choice, and I can imagine the temptation to go for the heavier scope because its more readily available. All id like to add to your quandry is that i had two great refractors some time back, a largeish aperture but heavyish ED apo and a light weight but small ED apo. I found that after buying the smaller scope I would use the little grab and go more often and for longer periods. It never failed to impress me despite its diminutive size! Perhaps the lighter scope may prove to be the wiser option in the long run?!

Looks fantastic! Can't wait for your view on the views in your review!!

It's nice to hear your views on the ST102. It really is a capable grab and go rich field refractor, which when used for its intended purpose, which is low power wide field views of nebulae, clusters, comets and fabulous rich star fields. As far as its lunar and planetary ability is concerned, it's not designed for such observing. It is after all a specialist instrument that probably gets bad press because it low price, short focal length and achromatic design. I have to say I have a soft spot for the ST102, but an even softer spot for its big brother the ST150, which is a superb RFT. I wouldn't be put off buying a ST150 because of reports of its CA level. You will only notice the CA on the brightest stars. It's RFT ability is breathtaking!

Very, very....Very Nice!!!

That's beautiful Matt! A few years ago I bought an Equinox ED80 purely for its portability. It was only after I began using it that it very quickly revealed itself to be a very capable scope. I used it far more often than my Equinox 120, and on some nights it even gave a more pleasant view. It was certainly easier to use, so I found myself going out into the garden for just a five or ten minute session. More often than not those few minutes turned into an hour or more, observing the moon using a binoviewer. Jupiter revealed five belts with the red spot easily visible, as were shadow transits and some of the major belt detail. Dropping down in aperture can certainly prove useful at times.

Sorry, I haven't got a clue! I bought it cheap from a local garden centre about five years ago. They'd bought all new seating for their staff and had several hydraulic swivel chairs on sale for about £10 each. Most of the time I prefer to stand while observing, but there are times when sitting comfortably, especially using a seat with a back rest, is most welcome.

That's a beautiful scope John, and I'm certain It will be a terrific performer too. It would look even better on a classic mount like that of the Unitron or Polarex. Truly droolworthy!

For only £12,000.00 more, you could save yourself packaging worries and buy a 152 triplet from that Japanese company. Their name eludes me momentarily!