New APO - TEC 140 possibly ?

[Retro Gear]

Help selecting a new telescope would be appreciated. My current position is – I have a Meade LX200 12” that I'm going to defork and use the OTA on a new equatorial mount (the subject of a separate post – probably going to be the Mesu 200) and purchase a new refractor. I particularly like planet / Moon / Sun observation hence the new refractor – the Meade for everything else.

My budget (slightly flexible) is £4000, I would like a 150mm APO refractor and would use it for visual and (later on when I have the right kit) imaging. So my initial wish list comprised the Esprit 150mm ED, Lunt Engineering 152mm ED and the Explore Scientific 152mm ED. Then I joined SGL and started reading the amazing reviews of the TEC 140 – that's when the mental torment started ! Now obviously the TEC is beyond my stated budget but if I forget about ccd cameras and other bits & pieces for the foreseeable future I could stretch the refractor budget to enable the purchase of a TEC 140 (I have talked to my wife about this and she is on-board with me getting the best we can afford). So whilst it would appear to be the so called “no brainer” there are few things apart from cost I have to consider.

The reviews / posts etc. I've read about the Esprit / Lunt / ES instruments would appear very positive (with the possible exception of some colour fringing at certain magnifications noted with the ES and its carbon fibre tube causing slow thermal stabilising). I'm 65 with eyesight to match – my vision is not that bad but obviously not that of a younger person either – I wear glasses most of the time. I have never had the opportunity to look through any of these refractors. So I realise this is a subjective thing (and therefore difficult for other people to answer) but is it likely that I will really notice a massive difference between the TEC and the other scopes mentioned ? I would think and hope I would but just wondered if SGL members have had the opportunity to asses / compare these scopes.

Also – I would like to use the refractor for solar obs at some point way down the line when I get suitable filters (narrow band H-Alpha etc – ouch! - the cost!). I realise that dedicated instruments are available for solar viewing but I thought having purchased a good quality refractor it would be a shame not to use it. I have read that oil spaced instruments are perhaps not ideally suited for solar work (heat etc..) but I would have thought that the correct filters would deal with this. Anyway – maybe I've misunderstood that point.

So – enough rambling – any help with these points or perhaps APO's I've not mentioned would be appreciated. I guess it might seem a bold start for a relatively inexperienced person like myself to start off with a first refractor like a TEC 140 but I've waited & saved a long time to get some descent kit and obviously I want to get the right thing.

Many thanks for reading.

Will

 

[Starlight 1]

Its not a post that I can reply to , my Tak fsq106ed was £4000  but this is a good post so it will nice see the reply .

[michael.h.f.wilkinson]

I have looked through a TEC 140 (Olly's) and it is a very good instrument indeed. I cannot compare it to others, except that the Esprit is not suitable for use with a Herschel wedge for solar white light, due to rear Petzval element (flattener). The TEC 140 can be used that way (according to authorities like the maker, and @Montana ). With a full aperture ERF (or front-mounted etalon if you REALLY feel like splashing out) you can do H-alpha as well. Most Ca-K modules are rated to 4" aperture, so you would need to stop it down for that use.

 

[Retro Gear]

Michael – thank you for the information – I have to confess my ignorance and had to look up what Herschel wedge did – but that's why I'm here to learn. I've used a Thousand Oaks glass front filter with my Meade which has been fine. Is the Herschel wedge/field flattener problem uniquely associated with the Esprit? Yes I would like to go the front mounted etalon / rear blocking filter configuration eventually (once I get the scope purchased) - would going this route bring the Esprit back into play as a viable purchase? I realise it's crazy expense but if I have a really good refractor I would have thought investing in good kit to go with it would be the way to go. I'm really looking forward to getting all this gear together.

Many thanks

Will

[Davey-T]

On the subject of the budget a front mounted ERF for the 140 would be around £1000.00

Dave

[cs1cjc]

Or you could consider the APM 140mm F/7 FPL53 doublet: http://www.apm-telescopes.co.uk/apm-140-980.html

[ollypenrice]

If you get a good example of any of these big apos I doubt that you will see a vast difference between them. However, with a TEC you can be pretty sure that you will get a good one. I'm very fond of mine. I like the views it provides on all kinds of target. I like the simple, high quality construction and finish and I like the fact that the boss replies to your emails - and you know who he is. The TEC140 is expensive but it is not insanely expensive. In visual use its colour correction is sensibly perfect - at least to my eyes which are a similar age to yours. In DS imaging the blue is not always kept under perfect control but here I'm nit-picking. The image I usually trot out in TEC140 discussions is this one. No fancy processing went into Alnitak here. It appears as a double, cleanly split, and is far better controlled than it is in my Takashi FSQ106N - though the TEC has aperture advantage of course.

With the TEC flattener the field is enormous, evenly illuminated and supremely flat, though these qualities are really of interest to the DS imager. However, they do affect resale value.

Olly

[mikeDnight]

On 19/04/2016 at 13:52, Retro Gear said:

Help selecting a new telescope would be appreciated. My current position is – I have a Meade LX200 12” that I'm going to defork and use the OTA on a new equatorial mount (the subject of a separate post – probably going to be the Mesu 200) and purchase a new refractor. I particularly like planet / Moon / Sun observation hence the new refractor – the Meade for everything else.

My budget (slightly flexible) is £4000, I would like a 150mm APO refractor and would use it for visual and (later on when I have the right kit) imaging. So my initial wish list comprised the Esprit 150mm ED, Lunt Engineering 152mm ED and the Explore Scientific 152mm ED. Then I joined SGL and started reading the amazing reviews of the TEC 140 – that's when the mental torment started ! Now obviously the TEC is beyond my stated budget but if I forget about ccd cameras and other bits & pieces for the foreseeable future I could stretch the refractor budget to enable the purchase of a TEC 140 (I have talked to my wife about this and she is on-board with me getting the best we can afford). So whilst it would appear to be the so called “no brainer” there are few things apart from cost I have to consider.

The reviews / posts etc. I've read about the Esprit / Lunt / ES instruments would appear very positive (with the possible exception of some colour fringing at certain magnifications noted with the ES and its carbon fibre tube causing slow thermal stabilising). I'm 65 with eyesight to match – my vision is not that bad but obviously not that of a younger person either – I wear glasses most of the time. I have never had the opportunity to look through any of these refractors. So I realise this is a subjective thing (and therefore difficult for other people to answer) but is it likely that I will really notice a massive difference between the TEC and the other scopes mentioned ? I would think and hope I would but just wondered if SGL members have had the opportunity to asses / compare these scopes.

Also – I would like to use the refractor for solar obs at some point way down the line when I get suitable filters (narrow band H-Alpha etc – ouch! - the cost!). I realise that dedicated instruments are available for solar viewing but I thought having purchased a good quality refractor it would be a shame not to use it. I have read that oil spaced instruments are perhaps not ideally suited for solar work (heat etc..) but I would have thought that the correct filters would deal with this. Anyway – maybe I've misunderstood that point.

So – enough rambling – any help with these points or perhaps APO's I've not mentioned would be appreciated. I guess it might seem a bold start for a relatively inexperienced person like myself to start off with a first refractor like a TEC 140 but I've waited & saved a long time to get some descent kit and obviously I want to get the right thing.

Many thanks for reading.

Will

 

Hi Will,

I feel that out of the refractors you've listed the Tec 140 is robably the best choice. The Tec is not mass produced and its optical quality is up there with the very best, plus it's resale value, should you ever decide to part with it, will remain high. The super fine optics of the Tec will show you stunning planetary detail. You won't see any perceivable advantage by going for a 152mm as its quality of the optics that matters most for planetary and the Tec has it.

AstroPhysics have no issue with using their oil spaced triplets for solar observing without the use of a full aperture filter. A 2" Herschel wedge combined with a single polarizing  filter attached to your eyepiece will give you great views of the Sun, and should not harm your lens one jot. The lens does not get hot as its at the focal point where the heat is concentrated. That's why a scope with a Petsvel design should never be used for solar unless a full aperture filter is used. If you're worried about damaging the oil, you might consider going for a top end air spaced triplet such as a Takahashi TOA 130 or a TSA 120. 

Mike

[cs1cjc]

The practical option is of course one of the 120mm (118mm if you are bring picky) Skywatchers, which are reliably good.  The only problem these seem to suffer is that in some the lens cell pinches at low temperature. Mine is fine.  It is usable immediately and takes only about 40 minutes to be at its best.

I also do not think that you would get a bad APM.  Mine made its way undamaged from China to Germany and then to the UK , but was poorly aligned when it reached me.  However it was realigned by APM without a fuss and now tests well.  Future models are coming with a star test to reassure buyers and a more robust lens cell.  I cannot give  proper review of it though, because drugs I am taking until June effectively prevent me from handling cold objects...

[Davey-T]

You could always buy a SW120 while you're waiting for the Tec140.

Dave

[Retro Gear]

Chris – I'm now looking at the APM scopes – there appears to be quite a few options available – hope your health improves soon – astronomy and handling cold objects go together unfortunately don't they.

Mike – thanks for addressing the oil issue – I think I would like to use a full aperture filter arrangement particularly after reading this article (amongst others)

http://www.skyandtelescope.com/observing/guide-to-observing-the-sun-in-h-alpha092321050923/

once I can afford it – I'm still reading about this equipment. Sorry to be a bit dim but is the Petsval design optics an inherent part of the Esprit scope or is it associated with the field flatteners ?

Olly – I think the image you have presented says it all – and yes it's getting a good example of an instrument that can make or break things – I have a rather poor example of a Meade LX200 GPS and I know from reading posts by other owners of this scope that they think very highly of them. Providing the TEC's oil spaced arrangement will not be affected when used for solar observation/imaging (using appropriate filters) then I'm going to try and stretch the budget to get one (although I'm looking at the APO scopes as well). On the subject of purchasing it – I note owners on SGL seem to have purchased direct (I assume) from TEC – just wondered if this is still the best route - I've seen them for sale on Baader Planetarium's web site. Presumably by contacting TEC in the USA you get to deal with Yuri Petrunin directly ?

Dave – hmm … the wait might be a long one I guess – if I can get my existing LX200 deforked and mounted on a new mount (hopefully the Mesu 200) then I'll be good to go whilst waiting (any thoughts on how long - looking at Steve (kirkster501) recent purchase – it took about 7 months)

Thanks to everyone for the reply.

Will

[ollypenrice]

All three of the TECs I know personally, including my own, were bought second hand so I don't know about dealers.

Olly

[Davey-T]

43 minutes ago, Retro Gear said:

Dave – hmm … the wait might be a long one I guess – if I can get my existing LX200 deforked and mounted on a new mount (hopefully the Mesu 200) then I'll be good to go whilst waiting (any thoughts on how long - looking at Steve (kirkster501) recent purchase – it took about 7 months)

Thanks to everyone for the reply.

Will

Lucky you don't want a AP Starfire, about a 10 year wait at one time 

Dave

[DaveS]

You could have a word with Rupert at Astrograph,

http://astrograph.net/epages/www_astrograph_net.sf/en_GB/?ObjectPath=/Shops/www_astrograph_net/Products/AG-TEC140-35

Currently quoting 2-4 months.

There are a couple of bigger TECs on their site, but make sure you're sitting down before looking at the price .

[Retro Gear]

Davey-T Yes – 10 years is a bit long to wait at my age – also they only seem to have a single APO scope in the price list.

DaveS – thanks for the link – not seen that site before – looks a better price for TEC 140 than Baader Planetarium as well – the bigger ones are way out of reach but I'm sure amazing to use.

Doublets are so much more affordable than triplets but I guess you get what you pay for – from what I've read you see the difference more in imaging than visual use (I hope to do both). Lots to think about now – thanks for your help

Will

 

[Retro Gear]

Having a bit of a reality check at the moment - I've read so many posts/articles/suppliers web site info etc. regarding scopes I hit an information overload wall and decided to stop and have a re-evaluate where I'm trying to get to.

I'm quite happy to be shown the error of my thinking but better now than later when I've purchased stuff.

TEC 140 would be amazing in all respects from what I've read and pushes my budget from £4000 to £6000 which may be doable. I would like to do visual to start with and later imaging once I get more experience & confidence. One item (on Ian king Imaging) said “Remember! It is far easier to obtain quality images with perfect tracking by using a high quality short focal length and small aperture instrument, providing you use a CCD camera that provides a good enough sampling rate”. So I started thinking perhaps I'd be better getting two APO scopes - a 150mm 'ish doublet or triplet for visual and good quality 80mm 'ish for imaging. I know doublets will probably (or definitely) show some CA when used for imaging but from what I've read they are fine for visuals.

In cost terms it could work out OK i.e similar to the TEC140 – for example;

Borg 89ED f4.3 Set B08943 with Feather Touch Focuser £2,280 (from FLO)

APM Telescopes 152 F8 Doublet APO Refractor with 3” Feather touch Focuser £3,449 (from Astrograph) Or the Esprit 150ED Triplet £3,999 (from FLO).

I've sort of lost my way with this a bit since I'm thinking ahead to ccd cameras and what would make a good affordable match with the scope(s) I might get. Any help – including a slap around the head to get me on the right track would be appreciated

Will

[Davey-T]

You will discover as many before you, including myself that unless you decide to image a fairly specific range of targets you need more than one scope camera combo, even the esteemed Mr Penrice is committing to a long focal length imaging scope as well as the Tec140.

Your LX200 will fulfil that role then a widefield 60mm / 80mm triplet and possibly a big doublet, and probably two cameras of different spec's and lots of other peripheral expensive bits.

Then after a string of cloudy nights you may get a hankering to do a bit of solar 

Dave

[ollypenrice]

38 minutes ago, Davey-T said:

You will discover as many before you, including myself that unless you decide to image a fairly specific range of targets you need more than one scope camera combo, even the esteemed Mr Penrice is committing to a long focal length imaging scope as well as the Tec140.

Your LX200 will fulfil that role then a widefield 60mm / 80mm triplet and possibly a big doublet, and probably two cameras of different spec's and lots of other peripheral expensive bits.

Then after a string of cloudy nights you may get a hankering to do a bit of solar 

Dave

Very true. The big thing for me about refractors, though, is that are highly predictable and when your role is one of 'provider' that becomes hugely important. The TEC can image galaxies, albeit at an unfavourable scale and what it can do it can always do. 'Argh, the collimation has shifted,' is a very big deal in my situation. But multiple scopes have a lot going for them.

Olly

[Retro Gear]

OK – multi scope/camera combinations is the conclusion I came to once my brain had time to assimilate (oh no – I sound like a Borg – sorry ) the many bits of info. At least I can do that in stages once I have more experience instead of going for a single combo that would probably not encompass the applications I would like to use it for. It's the “lots of other peripheral expensive bits” that I'm mindful of. So I'm going to lower my sites away from the excellent TEC 140 and focus on finding a good quality alternative that will leave me with cash to get the peripherals I'm going to need. I definitely will be doing some solar (I've enjoyed doing that with my LX200) and so I'm planning the expensive bits that will be required for that. I'm retired now so cash can be a bit tight although I have saved for the new equipment – that's why I'm trying to plan wisely and get what I need to cover a range of astronomy interests rather than a single item that although excellent will gobble up most of the budget.

Thank you for your help – I'm sure I'll be back for more guidance once I've re-evaluated my plan/objectives.

Will

[Davey-T]

These are quite nice, I have WO 110FLT that is pretty good, you need to budget another £240.00 for the flattener, all these little extras

They also used to do a 123mm they come up S/H sometimes

I wait for my pension to arrive every month then see what I can afford on my want list 

Dave

https://www.firstlightoptics.com/william-optics/william-optics-flt-132-ddg.html

[Retro Gear]

Thanks Dave – that looks a nice piece of kit – I'm in the process of checking out alternatives today and that looks interesting – perhaps need a larger objective than 132mm but not sure yet. Yep – I'm joining the “lets see what's left at the end of the month” team and squirrelling it away (the wife has new kitchen plans – need I say more!).

Will

[Neil27]

Hi Will,

I have been watching this thread with interest, as like you I had very grand plans and sometimes after a lot more thought and evaluation you sometimes come back to something more useful to you and also without the budget constraints.

No one scope can fulfill all your requirements, unfortunately it hasn't been invented yet, 'why do you need another telescope dear' I would imagine is often heard in many of our households and will continue to be heard!

Some great advice given and I think your thoughts nearer the end of this thread are probably nearer what you actually 'need' rather than actually 'want'.

Whatever you decide you are going to have some lovely glass to look through and image with.

Have fun shopping and my deepest sympathies to your wallet regarding your kitchen as well ?

[DaveS]

I'm thinking.....

How about starting with one of the many excellent 130 f/7 triplet apos kicking around for about the £2k mark for visual, Astrograph has an interesting Tecnosky lanthanum job.

Now add a fast 80mm apo for imaging if you're feeling flush, an Esprit 80 f/5 perhaps with flattener or a TS 80 f/4.4 six-element job with built in reducer / flattener for around the £1k mark depending on exchange rates.

At a later date you could add a 1x flattener to the 130 to give a 910mm FL imaging scope, and a 0.75 reducer / flattener for a 680mm FL.

A 130, plus 80, plus the two flatteners would probably still come in at less than a TEC 140.

[Retro Gear]

Hi Neil – thank you for the encouragement and yes it has come down to what I need rather than want - like many things (just getting that message over to the wife RE: kitchen ). I think the multi-scope route will be the way to go, once I make a decision (short list) I'll post and you can have a look and see what you think.

Will

[Retro Gear]

Hi DaveS – looked at the Tecnosky (amongst others) on Astrograph – is the lanthanum coating used by other manufacturers – haven't come across this scope before (not that means anything) – would like to see some reviews. The options for 80mm you've mentioned are amongst those I've been considering – I've sent an email to FLO setting out requirements/restrictions etc. with a view to putting a realistic package together (including all those nice peripherals that I hadn't thought of when I first came under the spell of a TEC). Watch this space for progress – thank you again for your help.

Will