Tak TSA 120 or a SkyWatcher Esprit 150ED?

[Tonk]

I'm on the fence between two refactors. Both scopes are close to my budget limit  (one more than the other) and I'm buying the scope to be remotely operated from southern Spain for imaging. The specs of the two scopes are:

1) Takahashi TSA 120 ED triplet - 120mm aperture, FL = 900mm, F/7.7 - package cost £3,398      (the TSA 130 is a little too much over my budget - and the TSA 150 ! er no)

2) Skywatcher Esprit 150 ED triplet - 150mm aperture, FL = 1050mm, F/7 - package cost £4,000

Similar focal lengths and focal ratios. The final costs will be slightly more as I'll be selecting a motorised focuser plus other assortments such as  a field flattener.

What sort of difference is the extra 30mm aperture of the Esprit going to give me over the TSA ? Would you emphasise resolving power or is colour correction a deciding factor (or is this unfair to the Esprit)

Which would you choose?? - is the quality of Tak going to weight over the Skywatcher - or is this premium Skywatcher got a good enough reputation not to be worried. Are Taks over priced for what they deliver? Too many questions!

Any help in making this decision  would be greatly appreciated.

Thanks Tony

 

PS the "package" versions have various spacers and camera adapters - the bare scope option I looked at is ~£400 cheaper with both scopes

 

[Owmuchonomy]

Have you looked on UK ABS, there are two very tempting TAKs on there!

[gnomus]

Would you have to budget for a better focusser on the Esprit, I wonder?

[ollypenrice]

For remote you need bomb proof mechanical integrity. You also have a long lead time between trying the kit and finding that it does or does not perform. You then have an even longer lead time to get it fixed, and the cost of getting the changes installed at your remote site. The temperature extremes of southern Spain are probably even greater than we experience here, but in the same order of magnitude. This has a big bearing on the quality of lens cell design.

Resolving power is not the big deal. There is a small difference in focal length, and so field of view and resolution. On occasion one will be more suited to your particular target, on another occasion that will be reversed. The difference in FL will average out to being of zero imortance over a range of targets.

Which of the two instruments has the best record in terms of quality control? I know what I think but the opinions of just one person are likely to be anecdotal so I won't express mine.

Have you factored in any necessary field flatteners?

Have you considered a TEC140?

I'd be after that big Tak on ABS myself.

Olly

[Tonk]

Thanks all,

Olly - its not going out to Spain for many many months yet - so I'm setting up a dummy remote in my backyard obs at present - starting out with the mount control - that's currently in hand. Camera comes after that and finally the odds and sods such as focus, heaters, weather station (to feed my 10Micron refraction data). Per has a new gear control box I want to look into as its optimised for 10 microns

Yes I had considered the TEC 140 - actually been considering that for years but I still scouting around in case I missed anything.

 

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Have you factored in any necessary field flatteners? 

 

yes - as I noted above ... "plus other assortments such as  a field flattener"

 

 

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The temperature extremes of southern Spain are probably even greater than we experience here, but in the same order of magnitude. This has a big bearing on the quality of lens cell design.

 

Right this is the critical stuff that I was not fully aware of - I'm aware of pinching but thought that was an issue with running refractors in very cold climates - that tip is worth its weight it gold - CHEERS!

 

I'd be after that big Tak on ABS myself.

 

If you mean the 150ED - it went last Feb  - but at £5,700 was slightly too much - eats into camera budget

[Tim]

I cant speak for the Taks, but I do have a Skywatcher 150ED in my obsy and happy to answer any particular questions on it that you may have.

In short, the optics on mine are pretty much perfect, colour correction is excellent, and the complimentary field flattener gives a good flat field across my full frame camera chip. I can provide images if you want to see them. I have noticed no aberrations, pinched optics, unusual flares or anything else untoward when used in the UK standard temperature range. As temperatures drop during the night I usually refocus a couple of times, by a handful of microns. I'm waiting for the stock focuser to let me down in some way so that I can justifiably upgrade to a Feathertouch, but so far no joy. It holds tight, even with a big camera, OAG and filterwheel on the back, doesn't slop, skew the image, or get 'sticky' with temperature changes.

I had an engineer make me a specific adaptor to go from the field flattener to OAG, with a 1mm spacing ring to allow for a different camera. I sometimes use a dewstrap wrapped around the cell if it is really moist out, but these days, on really dewy nights, I dont bother imaging, the results are rarely up to scratch anyway. That said, I have never had a problem with the lens dewing anyway, it's just a precaution.

Let me know if you have any queries

[Tonk]

Ye gads I've just seen the other one - up in the last 24 hours - hummm tempted - very tempted

[mikeDnight]

Quality over quantity every time! The 1/20th wave optics of the Tak TSA are perfection incarnate. Plus the Takahashi is a known quantity and its world class air spaced triplet lens is protected by a superb thermally compensating cell, and its resale value, should you ever decide to sell it, will remain high. 

Mike

[Tonk]

Thanks again everyone for chipping in. Yeah the quality thing takes priority. So going to middle ground that still is within my budget I'm going to take a look at a used TOA 130NS very soon - possibly tomorrow.

The TOA150 on ABS is the second ad for a 150 in a couple of months and reading between the lines on the ads I suspect its the same scope - new add says recently acquired but need to sell.

[Retro Gear]

Looking at similar scopes myself – not sure what the difference is between TOA-130NS and the TOA-130S but you can get the latter new (Harrison Telescopes) for £4299 – not sure about delivery times. Interesting point about the same Tak 150 possibly appearing on ABS within a few months. I wouldn't be able to tell a good from bad used scope at the moment so I'm probably sticking to a new one and pay the financial penalty.

Will

[Tonk]

Interesting point about the same Tak 150 possibly appearing on ABS within a few months. I wouldn't be able to tell a good from bad used scope at the moment so I'm probably sticking to a new one and pay the financial penalty.

 

What I find odd its the asking price - £5,500 for a scope that's ~£10,000 new. Too good to be true?? I thought that used Taks usually fetch ~80-85% current retail less VAT 

[mikeDnight]

4 hours ago, Tonk said:

 

 

 

What I find odd its the asking price - £5,500 for a scope that's ~£10,000 new. Too good to be true?? I thought that used Taks usually fetch ~80-85% current retail less VAT 

Of course it could be that the seller simply wants a quick sale so as to buy a less burdensome  scope. I advertised a Takahashi FS 152 mounted on a Losmandy G11 for £4500.00 a few years ago. It sold in less than 24 hrs. At the time I wanted rid of the scope to buy a more manageable set up. That shows how stupid I was. I doubt I'd do the same thing now, but i am prone to rash decisions from time to time.

Mike

[Tonk]

Deed is done - I'm now the owner of a TOA 130

[Retro Gear]

Good for you . Please post your thoughts on the 130 once you get a chance to use it as I'm interested in getting one of these in the near future. Snowing here earlier - rain now - probably is in Leeds as well. Good luck with your new scope.

Will

[Tonk]

Hi Will, will do!

 

 

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not sure what the difference is between TOA-130NS and the TOA-130S but you can get the latter new (Harrison Telescopes) for £4299

 

 

I'm sure the first is the "package" option - it has a few extra accessories. The second should be the bare bones OTA - **no** finder and finder bracket etc. (only mount attaching cradle). The 130-NFB and 130-F variants are similar package/non-package but with a giant 4" focuser/rotator as opposed to the stock 2.7" focuser. I may be wrong in this.

Picking up the NS (S) variant was useful for me as I'm removing the stock 2.7" focuser for a motorised FeatherTouch. The difference between the S and F variants is an incredible £1,100 so it would have been difficult to justify getting that large focuser to take it off and put it aside!