TSA 120 Trouble!

[Waxing_Gibbous]

My new Takahashi TSA 120 is exhibiting poor behaviour.
There is very slight, yet noticable and annoying CA on Luna in all my EP's (see sig). The fringing is confined to the very limb and does not 'bleed'. Its lessened with narrow-field eyepieces but does not go away.
Luna's "top" is always blue/violet, "bottom" is always green/yellow.
Fringing is independant of height above horizon. Its the same at +20* as it is at +90*.
The same is noticable on Mars.
A Lunar filter eliminates it entirely.
The effect is not evident on brighter stars, but they've been a little washed-out lately with the full moon. Star tests are ,AFAICT, near perfect.
Contrast and deatil are incredible.
This is the first decent-sized triplet I've owned, and I know they are not immune to CF/CA, but does this sound 'normal' for this scope. I would prefer that its colour correction not depend on a $10 piece of glass.
I don't recall any fringing in the TEC/WO 110 or SV 105 that I viewed with earlier this year.
Thoughts?
Ta.
Peter

[gbeal]

Peter,
wow, you will be living up to your description then.
Maybe ask another Peter, "EXFSO" as I recall him having issues with his early TOA from memory.
I suspect collimation, or incorrect rotation of the elements, whether it has always been like this, or gradually happened and become more apparent is anyone's guess. I agree though, it should not be "normal" I don't recall my TSA102 being anything but perfect.
Good luck.
Gary

[casstony]

Peter, I think your problem might disappear if you try observing straight through, ie. no diagonal. If so, you might need to use a mirror diagonal instead of a prism.

Cooling could be an issue too if you observed the moon with a warm scope which had cooled by the time you shifted to a star?

[Waxing_Gibbous]

Hey Chaps!
Thanks for the input. I don't think cooling was an issue as it had been outside for an hour. It should be collimated at Texas Nautical.
I will pursue the matter.
Any other users with this foible chime-in,, pplease.
Ta Peter

[Exfso]

Peter, my TOA130 has more frequent flyer points than Kevin Rudd. It has been back to Japan 4 times now. Mind you one of these trips was my fault and the other was caused by indiscriminate spraying of repellent by someone that caused my coatings to become "stuffed". The original problem I had was astigmatism, which the local rep here I dont think believed could happen. I then decided to deal directly with Takahashi and they were first class. They got me to send the scope back to them for which they paid the freight, and fixed it, sort off, but it was not satisfactory. So they then sent me another 130, at one stage I had two of them here, and I picked the best one of the two. Incidentally this was the one I "dropped" and then both scopes went back to Japan. The damaged one was rebuilt, new lens cell and OTA, dew shield etc. (Insurance is good)
If you need the name of the guy I used, PM me and I can give it to you. I certainly dont believe you should be getting any color regardless of cooldown. What I would be doing is taking an image which shows up the problem and email it to the guy I am referring to from Takahashi, he will refer it to the relevant optical technicians they have, and they will take it from there.
If possible do a star test and send that as well

EDIT; I just realised you are in the USA, definitely contact TNR they are 1st class I believe. If you are not a member of the takahashi uncensored yahoo group, I recommend you join. I gather it is run by TNR, but I stand to be corrected on this. http://tech.groups.yahoo.com/group/UncensoredTakGroup/

Cheers

Peter

[Waxing_Gibbous]

Pete,
Hi.
Actually I'm in S. Victoria!
If you could PM me the name & contact details that'd be great. I'd send you one, but I'm also having Telstra server woes at the moment and it takes about 1/2 hour to send one!

I'm waiting on a call-back from the original and very helpful Californian vendor to see if it goes back to them or to Tak directly.
Alas, I haven't really got the set-up to image properly with the Tak, but I could try an EP projection though that's liable to make it appear worse.

Its very disappointing and not just because of the time and money. :(
I'd hoped I'd never have to get another refractor and I saved for yonks. I did my research and concluded that The Tak hit the sweet-spot of aperture, IQ and portability. Going on what was said on-line, I hoped the chances of getting a duff one were very, very low compared to say a Skywatcher/Orion/Nanjing product as I've been-there-done-that ,with them. .
I'd known Taks to have mechanical foibles, but rarely optical flaws, but hopefully the lovely, lovely people at Takahashi can sort it out!
(You never know who's watching!) :)
Thanks again for the heads-up
Peter

[Exfso]

Sorry Pete, with a name like Elktooth county, I assumed it was USA. Will email you the contact detail. I have never had any color in the 130 unless it was out of collimation or had been dropped...;)

[Waxing_Gibbous]

:shrug: Thing is: other scopes I've had have endured equal hardship and survived.
Oh well. Thank goodness for the meds!

[JohnG]

Hi Peter

I did a visual check on my TSA-120 this evening for you using a 16mm Nagler. The edges of the moon showed no extraneous colour at all, a clean, crisp line with no abnormal fringing.

Sounds like it has had a bump in transit.

Now to put the CCD back on :).

Cheers

[Waxing_Gibbous]

Thanks John.
Thats very useful. Always good to know its NOT one's eyes playing-up.
I got double confirmation from my leasee about 20 minutes ago. He's a birder and spent more on his 80mm Leica spotting scope than I did on the TAk!!! He noticed it right away unfortunately.
I too suspect a bump. Don't think I'll try any DIY re-collimation though! :D

[casstony]

Did you try looking straight through to eliminate the diagonal as a possibility Peter?

I had to send a lens to Vixen once and they let me unscrew the cell from the tube to send the objective alone - that way you can get a lot more cushioning around the package to prevent another bump.

[MuntiNZ]

It must have been a blardy hard knock mate!!!
These Tak scopes are built like tanks!!
Are ya sure they didnt run it over with a tank???
Never heard of this happeneing with a Takahashi before.

[Waxing_Gibbous]

Daz,
Apparently it happens pretty often. Re-collimation is the most common reason for Takahashis being sent back.
I have just spent a very interesting morning at CSIRO with my Father-In-Law who was research physicist there for some years.
Amoung his colleauges were Optical Engineers, Materials Scientists, Electrical engineers etc. etc.
I got to yakking with one of the optical people and naturally we got onto telescopes (he makes his own refractors with CSIRO cast-off blanks). He's very conversant with Taks as he owns 4 including an uber-rare, maybe 12 made, FCT125. He called one of the materials blokes over to join the discussion. This bloke is currently working on semi-rigid, non petroleum based, polysomethingorothers with high thermal retentative propertie. Insulating Foam to you and me.

To cut a very long story short, the way Takahashi packs their telescopes practically guarantees trouble.
The triple-box, Excelsior (foam thingys) and rigid Styro-foam construction is "highly sub-optimal'. The styro is in full contact with the scope lens cell. It is much too rigid and transnits too much energy to the OTA. As the rest of the OTA is effectively free-floating, the energy has nothing to do except bounce around inside the tube and cause mischief.
You can simulate this by hitting a bit of pipe on the end. It'll ring like a bell. Plant the pipe in the ground however, and all you get is a dull thud. The Excelsior that surronds the OTA does nothing to absorb the shocks.

There followed a lengthy and rather over-my-head conversation about 2nd and 3rd order wave propagation in solid media........
Again the upshot being:
In order for Styro to be effective, it needs to be molded or cut to the shape of the object, and then, itself surrounded by a superior shock absorbent material.
The front runner material by a long stretch? - Bubble Wrap!

This cheap, ubiquitous stuff is evidently regarded by in-the-know types as something of a wonder material and all are very jealous that none of them hold the patent.
Pound for pound, nothing even comes close.
Thiis particular department of CSIRO designs stuff for industry including delicate instuments for whatever. Before the final thing is sent off, and in order to simulate the stresses it will endure in-transit, the instrument's model or prototype is bubble-wrapped and tossed out the window onto the slope below. If it breaks, they add more bubble wrap until it doesn't. Experimental physics at it's finest!

The consensus was that Takahashi could save themselves a lot of grief and money by simply bubble-wrapping the OTA before packaging.
There you have it.
The Boffins have spoken and no-one need ever worry whether or not bubble wrap is good enough for their gear.

[MuntiNZ]

Yeah mate I invented that.

[Waxing_Gibbous]

:lol:
That's as may be but I hold the rights to divalent-watchamacallits.

Anyway, incredibly helpful and friendly Official Place / Takahashi, dealer in California will repair/replace the TSA120 for postage. Though I think I'll ship it in a Pelican (hardcase) if I can find one to suit.
So ultimately its costing about the same or more as buying one here, but you can't buy one here 'cuz there's a silly waiting list. A real Hobson's choice (anyone under 40 will have to look that up! :D)

I regret to say that this has been a pretty dissapointing exercise. North of 4K is a lot to spend on a scope. On top of that, I now have to spend another $3-400, plus paperwork, to ship to and fro for repair, with no guarantee that the same thing won't happen again.

Though I'd never previously owned one, I'd viewed through quite a few Takahashis and was always impressed. Based on this, I'd been touting them as AP/TEC /LZOS alternatives. However the dodgy packaging plus the rather nasty nick on the dew-shield, obviously sustained post-factory, would nudge me toward saying you can do better elsewhere. I'll certainly keep it if it comes back spot-on, but the bloom has gone off the rose, if you catch my drift.

If you are contemplating buying a TSA120 or any Tak from abroad, or anywhere for that matter, make sure they re-pack the thing properly or invest in a Pelican or Scopeguard case. If that puts the scope out of range, (both options are expensive) you are probably better off with a WO FLT110 an SV/TMB 115 or even an EON 120 as the difference in IQ is fairly minor. The first two come with protective cases, the latter, I think, does not, but re-collimating a doublet is a cinch if it's had a bang.

Jeez, If only they'd used bubble wrap!!!:mad2:

[Exfso]

Peter, if you contacted the Tak guy I told you about, I feel sure you would not have to send it back to the USA, especially seeing you are resident in Australia. Almost certainly they would want it sent back to Japan. I know with my issues, Takahashi paid for the freight, which was considerable I might add.
I have heard quite a few horror stories about scopes and handling that originate from the USA. I must admit all the trips mine has done back and forth to Japan have been very uneventful in that respect. I would definitely be pursuing that avenue.

[Tandum]

Have you had a look at collimination with a chesire? Works for me.
http://www.spacealberta.com/equipment/refractor/collimate.htm

[Waxing_Gibbous]

Thank you for the input guys.

Exsfo,
I thought I'd try the original vendour first, again, very helpful bunch, but given the cost of return post will certainly now check your guy out!

Tandum,
While I've had previous success collimating doublets, and even a Brandon triplet, there are no obvious "fiddle-points" with the 120.
Also, mucking about (my skill level :D) with the scope may void the warranty.
I've got a laser collimator but the super-fine adjustments needed to achieve perfect collimation are a bit out of my league.
In addition, though everyone who's looked thru' it has proclaimed "Out of Collimation", I still want to be sure ther are no actual errors in the lens group construction.
Also, for $4000 +, one would expect it to do what it says on the tin!.

Thanks again. Your advice has been very helpful and I'll try to make the most of it! :)

Peter

[DavidU]

I had a lot of trouble with damage to Uber expensive valve amplifier shipping.
Polystyrene packing is next to useless.
I'm suprised Tak ship scopes using this crap for packing.
The inertia of a heavy (yet delicate) item moving will be stopped by polystyrene like concrete.

[Exfso]

I have been told by Takashashi that collimating their air spaced triplets requires specialist equipment. Maybe they are saying that so it goes back to them, but I doubt it as they have a reputation to preserve. Takashashi actually have a small collimating scope, this is fine for the doublets, but will NOT work with their triplets. When one spends lots of $$$ on a scope, I reckon "horses for courses" applies. Leave it to the specialists to collimate, after all if they stuff up, they have to fix it. As I said previously with this sort of thing, they pay for it unless it is caused by the instrument being mishandled/mistreated by the owner, obviously in this case that is not so.

Cheers

Peter