Have I bought a lemon?

[Stratis]

Hi all,

When I first started out in astronomy I was deeply prone to impulse purchases.... in particular second-hand scopes on eBay and ABS, I always felt like I was at a dog rescue shelter and I wanted to take them all home...

Don't worry, I thought, that AstroMaster 114 will be fine with a bit of a clean!

It's fine, a Heritage 90 Maksutov will be a fantastic planetary scope, and you can use the mount forever!

SkyWatcher 127 blue-tube with an odd knocking noise? Easy fix, surely!

It got so bad that I have been thinking about writing a 'Newbie Scope Choices to Avoid' post, I have so much experience with small, rubbish scopes. Obviously this sort of thing had to end, and a year later I have sold off all three of the above scopes (with no misrepresentation.... apparently a lot of people like a fixer-upper...)  and managed to settle on my current stable of scopes, centred around my 102mm ED doublet which I have enjoyed immensely and has produced fine astroimages with an impressive colour control for a doublet. I'd managed to avoid the scope fever for an entire year, and then something happened.

A Teleskop-Service 115mm PhotoLine f/7 Triplet APO was offered to me for a very good price.... with a 3" Rack-and-Pinion focuser upgrade...

I had to have it, and was saying yes awfully fast... a 115 triplet has been my 'dream' scope for a long while now, but could never justify the £1600 asking price for a decent example, given what sort of SCT/newtonian aperture can be delivered for that sort of money. I also image on an HEQ-5, and am intimidated by the challenge of getting decent tracking with anything heavier mounted...

But, I have no idea what sort of scope this is! Are they decent? Is TS shipping garbage these days? I haven't had a RnP focuser since the AstroMaster 114, aren' they meant to be terrible compared to Crayfords?

Obviously it's not going to be a Tak Fluorite (it has FPL-51 glass up front), but assuming Quality Control holds up (I have had unbearably terrible scopes from Celestron and a fantastic one from Kunming Optics so QC seems to be a true lottery below £2k) do you guys think I have made a mistake?

I realise it may be too late either way but... just hoping for some context from you knowledgeable folks on these 115s

[baggywrinkle]

I have bought from TS and their products have been reliable, this is no Seben like device.

From what I have seen and heard the TS refractors are of good quality.

[Mrbloke]

There's only one way to find out!

[Chris]

Is that the one on ebay for 750? If so it looks like a lot of scope for the money, I was tempted myself

I think TS used to have a bit of trouble with pinched optics in cold weather, but this was a long time ago now. They are a very good company that I've used many times. I've never had trouble with any kit I've brought from them

You know the second hand market by the sounds of it, so you know there is always a tiny bit of risk involved.

[nightfisher]

This looks remarkably like the Altair astro version and is more than likely made by united optics in china, should be a good scope, my 102 f11 comes from this factory and its a good scope

[michael.h.f.wilkinson]

The pinched optics was an issue with the quadruplets, I recall. I have not seen such reports with the triplets. Regarding Crayfords vs R&P, a quality R&P is considered to be better than a Crayford by many imagers (less chance of focus slipping, just ask Olly Penrice (runs for cover))

[Skyline]

Its a lot of money for pinched optics and buying a lemon, you never know it might turn out to be the best scope you have ever bought. The only way is to try.

[beamer3.6m]

Can you not view it before you buy it?

[damnut]

TS have been producing decent scopes for some time, as above looks very similar to the Altair Astro range. I think you need to feed it a decent eyepiece and see how you go!.

Good Luck..

[michael.h.f.wilkinson]

The TS series are essentially the same as sold under a variety of brands. I got myself an 80mm triplet (with FPL-53 element) from that same series and it is a very nice little scope. I bought it from APM but TS sell exactly the same scope (the flatterner that came with mine was actually TS branded).

[Stratis]

The pinched optics was an issue with the quadruplets, I recall. I have not seen such reports with the triplets. Regarding Crayfords vs R&P, a quality R&P is considered to be better than a Crayford by many imagers (less chance of focus slipping, just ask Olly Penrice (runs for cover))

Ahhh that sounds alright then.

I'm not concerned about pinched optics particularly, with an air-spaced and (from what I am reading, un-cemented) triplet lens there is no separate element to overtighten, and if by some miracle this had happened it should be possible to remove the lens cell and take a mm or two of turn out of the tightener.... I've done it before with smaller lenses (with good results) so should be fine.

I guess what I'm concerned about is the level of quality TS are demanding from the suppliers; I know Altair are extremely picky about which lens cells they ultimately pass on to the public, I hope T-S are also putting the effort in to make sure the optical elements match up correctly and control colour like they should. 

Time will tell I guess . If I get a clear night, I will do a side-by-side comparison of the intrafocal/extrafocal colour profile of the scope and my other refractors.

I currently have the 102ED doublet, ST80 and William Optics ZS66 SD.... this should make an interesting colour comparison given the APO/mostly APO/semi-APO/achro spread of lens technologies

[ronin]

I would cease worrying, the scope will be fine.

FPL-51 and f/7 sounds pretty nice.

The scope will have come out of Longprng or U.O. (if they are not the same) and they have been making good scopes for years, not in the LZOS, APM, AP league but still good. Someone has been sensible and not tried to push the glass to or beyond it's limit by trying for f/5.5 or f/6.

Have you looked at the front page of the TS site?

Seen the building they seem to occuply ?

Small it is not, getting big enough to take over ESA.

[ollypenrice]

 I haven't had a RnP focuser since the AstroMaster 114, aren' they meant to be terrible compared to Crayfords?

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Honestly, the moderating on here used to be so scrupulous but now it seems any old profanity can pass unchallenged. Not only is the C-word not on the world filter, as it should be, but the most scurrilous assertions sail through unchallenged.       

Stratis, as a new member you are in the happy position of not having encountered my exasperated rants against the C-word focusers but I've penned a few, believe me. On the whole, horrible slippery things bent on ruining a good night's imaging. OK, this is an extreme view based on the thousands of literally useless c-words pumped out on more budget scopes. Some can actually be used to take a picture but give me an R and P any daty. Preferably Feathertouch please, santa! I currently use Feathertouch and Takahashi.

TS scopes are so numerous as to be variable but they'll be straight if you have a problem and this should be a good one.

Olly

[damnut]

You need a brandy & a lie down Olly

[ollypenrice]

You need a brandy & a lie down Olly

Wouldn't you, after hearing the holy R and P blasphemed in this way?!?!

Pass me another one...

 lly

[RLWP]

There's only one way to find out!

I do hope you are not Harry Hill

Richard

[Stratis]

Hehe this is actually quite interesting from my point of view, being a new astronomer a year or so ago I sought 'common wisdom' and in the succeeding year I have been forced to systematically discard quite a lot of it

50x per inch of aperture? Naah, my 4" APO can exceed that, my C8 can't really reach it.

You need to guide with a similar focal length to your primary? Naaah, Im guiding at one third the primary FL.

RnP suffers from slop and gearing issues? Naaah, not compared to Crayfords with anodized drawtubes...

For the interested, I have received more info about the scope from its former owner...

* He works for TS so hes only selling to make way for his 130mm FPL-53!

* He has found the FPL-51 triplet superior for imaging than FPL-53, on grounds of clarity

*. The scope has the new 3" RnP upgraded focuser, £500 RRP so I gurds Olly will be right

The scope is in the post and should arrive this week.... is there interest in a First Light report on this scope or is it relatively well-worn ground by now?

[Macavity]

Were it not for the pioneering spirit of some wo/men of SGL...

Others would have to pay full price for good stuff? [teasing]

Hmmm. The only Lemons I have bought have been Mounts!

I eventually learnt there were few alternative to the HEQ5.

I worried about much the same things though - "Better" refractors were not within my experience. Indeed, no direct comparison, but a recently purchased Altair Astro ED60-R has proved fine! Not to inflame passions, but I did notice the transition from Crayford-style (back) to rack and pinion on the "-R" series. I can only compare the AA R&P with my Monorails. The "spring-back" (backlash) of the new R&P can take a bit of getting used to... Maybe it will "ride up with wear" (or hopefully not, in this case)? 

As with everything else, telescopes are only as good as the weakest link.

At this level, just as likely to be (me!) the observer. No point worrying?

[DaveS]

Yeah, will be interested in a first light report.

J B Sidgwick quotes an empirical rule of 140 x sqrt D (Inches). But that's for a well corrected unobstructed 'scope. Reduce it for anything with a secondary mirror.

[laser_jock99]

??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????

Honestly, the moderating on here used to be so scrupulous but now it seems any old profanity can pass unchallenged. Not only is the C-word not on the world filter, as it should be, but the most scurrilous assertions sail through unchallenged.       

Stratis, as a new member you are in the happy position of not having encountered my exasperated rants against the C-word focusers but I've penned a few, believe me. On the whole, horrible slippery things bent on ruining a good night's imaging. OK, this is an extreme view based on the thousands of literally useless c-words pumped out on more budget scopes. Some can actually be used to take a picture but give me an R and P any daty. Preferably Feathertouch please, santa! I currently use Feathertouch and Takahashi.

TS scopes are so numerous as to be variable but they'll be straight if you have a problem and this should be a good one.

Olly

I might add that Crayfords aren't the nightmare on Newtonians as they are on refractors. On a Newtonian the weight of the camera et al isn't normally pulling straight down.

[ollypenrice]

I might add that Crayfords aren't the nightmare on Newtonians as they are on refractors. On a Newtonian the weight of the camera et al isn't normally pulling straight down.

True. I have a C-word on our Dob because that is always horizontal.

Olly

[damnut]

Glad to see the brandy worked Olly, I am sure after a bit of therapy you will be able to say crayford ..And to the Op, please do a write up, especially a first light.

[Macavity]

Isn't that the purpose of electric focussers - To hold things firmly in (one!) place?

But I am now replete with Bahtinov masks... (video) Cameras that *invert* the image 

in real time... There had to be a use for that one! I do rather miss my (sold) Borg

Helical focusser. My little ED (semi) APO might have been a genuine use for that!  

[Scott]

Hehe this is actually quite interesting from my point of view, being a new astronomer a year or so ago I sought 'common wisdom' and in the succeeding year I have been forced to systematically discard quite a lot of it

50x per inch of aperture? Naah, my 4" APO can exceed that, my C8 can't really reach it.

You need to guide with a similar focal length to your primary? Naaah, Im guiding at one third the primary FL.

RnP suffers from slop and gearing issues? Naaah, not compared to Crayfords with anodized drawtubes...

For the interested, I have received more info about the scope from its former owner...

* He works for TS so hes only selling to make way for his 130mm FPL-53!

* He has found the FPL-51 triplet superior for imaging than FPL-53, on grounds of clarity

*. The scope has the new 3" RnP upgraded focuser, £500 RRP so I gurds Olly will be right

The scope is in the post and should arrive this week.... is there interest in a First Light report on this scope or is it relatively well-worn ground by now?

always interested in first light reports... If I sneak you a fiver, can you say the r&p is rubbish 

Try putting the 'scope on a piece of fish. if it tastes nice, it's a lemon