John

Hi Mark, I'd read a few complaints from folks with the 152 ED's and some rather defensive posts including from the chap that runs APM. I started this thread on the CN forum: http://www.cloudynights.com/topic/535732-apm-lunt-152mm-f8-ed-doublet-optical-quality/ It's had a few diversions here and there, as you get on CN, but my summary is that I don't feel that my confidence has soared in the scope unless it's bought from a source where you can be confident of really good support should there be any issues. It's a bit inconclusive of course but when paying out a couple of grand or more I tend to be a bit risk averse I should get 2nd light with the LZOS 130 tonight, if it stays reasoably clear

I did get the Interstellarium Deep Sky Atlas Alan and I like it very much The innovative presentation of objects by visibiliy in aperture groups is clever and useful. It's more user friendly than Uranometria as well. Of course my other half wants to know why I need 2 detailed star atlases as well as Stellarium, Cartes du Ciel, S&T's Pocket Atlas and my old Nortons If I ever write a book it will be called "Astronomers Excuses and Justifications for Equipment"

I'd still like a 6" as well but it will have to avoid the mounting / handling issues that were presented by the Istar 6" F/12 that you might recall I had a little while back. I thought long and hard about an APM / Lunt 152mm F/8 ED doublet but I've seen enough doubts posted about their objective cells to put me off those a bit. The new APM 140 ED which uses an FPL-53 element looks interesting and is around the same weight / size to the LZOS 130 I believe. One of our members here has one of those. There is, or was, a nice Esprit 150 for sale here and I did think about that one as well. It's too heavy for my mounts at the current time though but they get great reports generally. The Tak was a limited edition of just 100 units worldwide (very unusual for Takahashi) and I managed to get the last one sold of the UK allocation. It's a slender lightweight OTA which cools really fast. I grabbed a couple of hours with it last night and the views of Saturn were pretty sublime for a 3.9" aperture scope, there is no CA whatsoever on anything and it splits tight doubles like nobody's business I cleaned the mirror of the 12" dob yesterday so that's ready for the darker skies and won't be left to gather dust just because a couple of flash new scopes are around

Great looking refractor How do you find the Altair Sabre mount with it ? I'm wondering about getting one for my LZOS 130.

Nope Alan - one Tak FC100DL Flourite and one APM / TMB / LZOS 130 F/9.2 Triplet

Lovely frac(s) kirkster Those flextube dobs still remind me of R2D2 when they are in the "down" configuration I've not posted a pic of my LZOS 130 F/9.2 in this thread yet so yer tiz with the ED120 for scale:

My original plan was to get one really top end scope but in the event two came along !

Thanks Alan - hope you had a great holiday

Yep - thats the grand plan, a half metre apochromat refractor. I've just got to get an observatory on a mountain top and I'll order the scope ! My 130 would make a half decent finder for that one

Thanks Dave Owning these two superb scopes is like a dream for me too. I'm very lucky to be in this position, I appreciate that. Mind you, comparing them with the Vixen and ED120 have shown that the optics on those are excellent as well. If I'm going to part with one the decision is going to be very tough indeed !

Very nice image John After many years in the hobby I've just managed to split Antares visually this year with my 5.1" refractor at 300x and later with my 120mm at the same magnfication.

I agree with Chris - despite the brightness difference between the components, it's the low altitude that makes it awkward. If you can get a lowish and clear horizon then a small frac should do it. I thought the secondary star looked grey-green but with all the "scintilating" going on with the primary I'd not swear to that !

Re: the above - I've had the ED120 and Vixen ED102 out together tonight going over similar territory to that which I covered with the TMB 130 a couple of nights back. Cutting to the chase, both scopes have performed really well and earned their keep despite their much more expensive companions. For a scope worth around 20% as much as the Tak and the TMB the ED120 in particular is an optical gem. I split Antares with it this evening although having done it 1st with the TMB 130 probably did help ! Mars and Saturn looked glorious through both scopes as well

It has a Feathertouch focuser Mark - not sure where I'd go for something better to be honest with you as it's even better than my Moonlites The tube is the lightweight Kruppax version. Fit and finish seem excellent - "Vixen class" plus a bit I'd say. The dew shield is flocked inside. I've put a 9x50 RACI finder on it and an AP 2" diagonal but, apart from trying binoviewing, I can't see a lot of other room for improvements

I think it is my old Istar Mark. I wasn't aware that it had moved on to Mark Turner but then there is no reason that I should. Another interesting, but perhaps more manageable, long achromat is the 5" F/12 on sale at ENS: http://ensoptical.co.uk/telescopes/--fr-telescopes-istar-127mm-f12-r30

I'd still like to get another 6" but it would need to be lighter and shorter than the 6" F/12 Istar that I used to have to ease mounting. I'm still expecting to use my 12" dob frequently when the darker nights are here. I've always thought that the ED doublet Synta / Skywatcher refractors had excellent optics for their relatively low cost and being able to compare the ED120 to more exotic alternatives seems to bear that out. I recall that the glass used in the objectives is sourced from Japan and I'm sure that I read somewhere that Canon (who make Tak objectives) were involved in some way in the design of the Chinese ED doublets. I've also recently been reading that Synta took particular care with the design of the 120mm ED objective including aspherising some of the curves.

I feel guilty now ! I'll be getting the ED120 out again soon I'm sure. Owning the Tak and TMB LZOS have clealy shown me what a great objective lens these Chinese ED doublets have. For a mass produced, relatively low budget production item they get very, very close to the premium ones. If I was to do a value for money assessment, the ED120 would win hands down.

Ok, some really excellent views from that session. Mars: Not it's most interesting face this evening but as good an object as any for a 1st light. Nice dark details visible around the paler plains in the centre of the disk. I quickly found that this scope supports high magnifications without breaking sweat. 250x - 300x showed a sharp and contrasty Martian disk. Saturn: Easily the best views I've had of the planet this opposition and despite it's low altitude, at times rivalling some of the best views I've ever had of Saturn. With the low altitude I didn't expect to see the C or Crepe ring much in evidence but the 5.1" refractor showed it beautifully. Ring structure was very sharply defined, Cassini Division a sharp black cleft all around the disk with the latter having a lovely 3-dimensional look to it. With careful examination the cloud belts around the disk were showing structure and the S edge of the main belt was distinctly uneven and undulating as it wrapped around the curve of the planets disk. All this at 300x as well Antares: Now this is a 1st - I managed a clear split of Alpha Scorpii . This star is really low down from my home and I just get a 30-40 minute glimpse of it between houses and trees. The star showed some colours from atmospheric diffraction but the 5th magnitude secondary star just around 2.5 arc seconds from the 1st magnitude primary was clearly defined. Never managed that one before ! Vega: Superb star test. No false colour whatsoever inside, outside and at sharp focus. A very similar presentation to the Takahashi FC100DL, except brighter. Epsilon Lyrae: At 300x you could park a car between the pairs of stars here. The subtle tonal difference between one pair was clear as well. Delta Cygni: Wonderfully split and very obvious. This pair can be a challenge for a 4" refractor but this 5.1" just makes it so easy. Lambda Cygni: Wafer thin split of this tight pair. 400x eased them from a touching pair to that hairline split of blackness. Again the best view I've had of this pair. My ED120 can't quite split this one but the extra 10mm of aperture seems to do the trick. Zeta Herculis: Again this marvelous scope provided my best ever view of this really challenging pairing. Just that much more definition of the secondary star, tight against the primary, than the excellent ED120 is capable of. Finished off with a couple of bright DSO's at 150x: M13: Enough aperture and pinpoint resolution here to really show this globular off. Stars resolved right across and a wonderful "diamonds on velvet" appreance to the stars surrounding the cluster. M57: Nice and and bright. Very contrasty, really looks like it should. Outer rim showed uneven thickness and central darker area well differentiated. I'm going to stop there. What an amazing scope to view through. 130mm of unobstructed aperture with a very high % of the light gathered ending up just where you want it to be. Absolutely no CA whatsoever on any target viewed tonight. Crisp, unambiguous focus even at 300x-400x. Wonderful stuff I'm going to think about a more sturdy mount though. The Giro II and hardwood tripod copes with the 8kg OTA pretty well but it's a long tube and with the sort of power that the scope can handle the damping of vibrations could do with being a touch quicker. Might even think about a driven mount as well for a change. The late Thomas Back certainly got the objective design right with this one and the LZOS factory were able to execute it to near perfection with their OF-1 / OK-4 / OF-1 triplet prescription. Probably the best scope I've viewed through in terms of sheer optical quality. I'm delighted with it

I've had the scope out and ready for some time so I snapped the photo's below. I'll post some notes on my experiences with this scope later but so far this evening the scope has been rather mind blowing !

It's excellent ! I got it from the Astroboot. It's the same one that comes with the huge 45/90 degree binoculars: https://www.firstlightoptics.com/helios/helios-quantum-7-25x100-binoculars.html With the addition of a DIY plate I found that it would fit the Giro mount easily. Its at least as stable as the 2" CG5 tripod that I used before and a touch taller as well. Better looking too, IMHO

Indeed it is Shaun

Lovely scopes folks ! Interesting that Tony's scope is designated the FL102S. I wonder if Vixen were contemplating a longer FL version but never quite got there ?

As I got 3 eyepieces with my 1st scope (60mm refractor) I guess I've never needed to buy any more either ......

Astro equipment buying terminology: "Never" = "a week or so" "Keeper" = "until I see something even more exciting ..." "95% of the performance of ..." = "but I rather want that additional 5% ....." And theres more I'm sure. We are all afflicted though .....

Sorry I'm a bit late on this Derek but I think the other posters have got it covered between them ! I have used the scope with my Lunt Hershel Wedge for a short session and it didn't explode or melt Not being a solar boffin I'm unsure if there are any major benefits in using an apochromat or ED doublet for solar viewing though - unless it's because they are generally well figured objective lenses I've not had enough use from the scope to attempt any sort of report on it but one thing that is noticeable right away with it is that it shows no false colour whatsoever, on any target, at any magnification and even inside and outside of focus (where most ED doublets do show a little colour). Vega was just a perfect white airey disk with 2 very fine and faint diffraction rings around it. It looked like an exemplar star test from an optical text book. Rather impressive