15 replies to this topic

[jeffcrilly2]

Refactor experts:  I have a question...

 

If one were in the market for a 6" class APO refractor, what would be the choices?

 

Here's some requirements I have for the decision...

- Ideally comparable optically and mechanically with the AP 155 f/7

- Likely a triplet

- No slower than f/8

- Reasonable availability

- Flattner and Reducer are available (these are a must have)

- Feathertouch focuser - specifically I'd like the focuser to be FT HSM / PDMS compatible (which I'm already using)

- Rings are available / included

- Price?   Perhaps under $10k

 

Thoughts?

 

Usage will be visual (planets, moon), and imaging w/ APC and full frame sized sensors - narrowband, LRGB, and OSC.

(Mounting is not an issue.)

 

Here's a list (other than the SVX I don't know if flattner/reducer are available for these).

• SVX152T f/7.9
• ES152 f/8 Triplet Carbon Fiber
• TS Photoline 150 f/8 Doublet
• APM 152 f/7.9 ED-APO Doublet (Nice price, too much color?)
• TOA-150? (focuser may be an issue, and it is pricey)
• Skywatcher 150 ED Triplet APO f/6.9

Anything else out there?

 

thx!

 

-Jeff

 

[rkaufmann87]

Don't forget the the AT 152 EDT from our sponsors.

[Lagrange]

APM also do a 152mm f/7.9 with an LZOS triplet lens and a Feather Touch focuser that should be within budget although you'd probably have to wait 4-6 months according to the APM website if you couldn't find a vendor with one in stock.

[salico]

Agema SD 150

Edited by salico, 24 January 2022 - 05:39 PM.

[ris242]

>TS Photoline 150 f/8 Doublet

 

possibly when they were selling the APM doublet?

 

 

But their Triplet FPL-55 Apos - 155 F/8

and they also have 140 F/6.5 's photolines.

[Mbenj2405]

WO FLT156, it works pretty sweet and they will sell with a 3.5" FT.

 

[Heywood]

Refactor experts: I have a question...

If one were in the market for a 6" class APO refractor, what would be the choices?

Here's some requirements I have for the decision...
- Ideally comparable optically and mechanically with the AP 155 f/7
- Likely a triplet
- No slower than f/8
- Reasonable availability
- Flattner and Reducer are available (these are a must have)
- Feathertouch focuser - specifically I'd like the focuser to be FT HSM / PDMS compatible (which I'm already using)
- Rings are available / included
- Price? Perhaps under $10k

Thoughts?

Usage will be visual (planets, moon), and imaging w/ APC and full frame sized sensors - narrowband, LRGB, and OSC.
(Mounting is not an issue.)

Here's a list (other than the SVX I don't know if flattner/reducer are available for these).

• SVX152T f/7.9
• ES152 f/8 Triplet Carbon Fiber
• TS Photoline 150 f/8 Doublet
• APM 152 f/7.9 ED-APO Doublet (Nice price, too much color?)
• TOA-150? (focuser may be an issue, and it is pricey)
• Skywatcher 150 ED Triplet APO f/6.9

Anything else out there?

thx!

-Jeff

I would suggest a 5.5 inch f/7 for $7400. That is, the TEC 140FL. It weighs only 19 pounds, is relatively small, is high quality, and will be almost indistinguishable from a true six incher. And TEC gives great customer service. Note:  If you call the TEC dealers, you can sometimes get a 140 fairly quickly.

Edited by Heywood, 24 January 2022 - 08:17 PM.

[bobhen]

You will be hard-pressed to do better optically than the APM LZOS F8 152mm triplet.  The price is around $8,700 USD. HERE is a link.

 

The Agema 150 F8 is also getting good reviews. It's a Fluorite "doublet" and you might have a pretty long wait. The price is around $9,200. I believe there are a few user/review threads here on CN about Agema refractors. 

 

CFF offers a 160mm F8 oil-spaced triplet for around $11,500. Excellent and you get a little more aperture but it's a little over your 10k budget.

 

The Tak 150 triplet is of course pretty heavy. I wouldn't worry about the focuser, it will most likely meet your needs. If you are dropping $13,200 for a TOA 150, the price of a FT focuser should not be too much of a concern, if you feel the need. The TOA 150 with its 2 ED elements will have superior color correction and an exquisite figure.  

 

If you want a value-priced 6" Apo, the APM 152 F7.9 doublet has nice mechanicals and gets good reviews. 

 

In the 6" apo class, price is a pretty good guide to optical and mechanical quality.

 

I owned an AP 155 for 17-years and I also owned a LZOS 105mm F6.2 triplet. LZOS optics are killer sharp and will best the lower-priced Chinese refractors on your list.

 

Good luck.

 

Bob

[etsleds]

The TEC 160FL as an oil-spaced fluorite triplet is nice and in some ways comparable to the AP155, available with Feathertouch and a good range of secondary optics. Used under $10K, new $12.5K.

[JimP]

I have had a good deal of experience with a fair number of 6 inch plus/minus Apochromats. The ones I would unconditionally recommend, ones I have had direct experience with, would be the AP 155 F/7, TMB (LZOS) 152 F/7.9, TEC 160 FL ,Takahashi TOA 150, and CFF 160. I can echo Bob’s comments about LZOS refractors having killer sharp optics, but I think any of the ones on my list can do whatever you want to do with a 6” Apo.
Not saying anything negative about any of the other scopes recommended. They may be equally as good but, I can’t say, as I have had no direct experience with any of them. 

JimP

Edited by JimP, 24 January 2022 - 09:39 PM.

[Jeff B]

To Jim's list, I would readily add the TEC 160ED.  My sample has one of the best sets of optics I've ever owned and will come in at around $8K  USD......if you can find one.

 

Jeff

Attached Thumbnails

• 
• 
• 

[weis14]

I echo the earlier comments about the TEC160FL and the CFF160.  I've had both and they are fantastic scopes, both optically and mechanically.  If you are willing to buy used, you might be able to find one at a reasonable price with a wanted ad.  It might take a month or two, but that is a lot faster than waiting for either scope to be built new.

[StarAlert]

To Jim's list, I would readily add the TEC 160ED.  My sample has one of the best sets of optics I've ever owned and will come in at around $8K  USD......if you can find one.

 

Jeff

+1  I bought my TEC160ED in October of 2020 and I haven’t seen another one for sale since. I’ll be letting it go after my new CFF180 arrives this spring. I don’t need (or want) 7” and 6” refractors. I’m thinking a 130-140mm might be a better companion for the CFF. 

[Adam Lake]

A big part of the equation here is, how quickly does this need to happen? I notice from the website you can get the SVX with Feather Touch 3.5" and reducer/flattener plus adapters for less than $10000. They're claiming 99% strehl and I'd presume you'd get paperwork supporting that. If you're willing to wait a couple of months one purchase and you're done, and if customer service is ever necessary I can personally attest to the fact that they're first rate all the way, Vic and company are great to deal with. If $ aren't an object I'd recommend the Tak (I ALWAYS recommend Tak ), used mine just last night and the views are unsurpassed, everything you need is available but it's all extraordinarily expensive. It's no coincidence that there's a $ sign in the logo...

 

You have a good problem. Let us know which way you go and good luck!

[drprovi57]

I  noticed the SW 150ED Esprit was not mentioned much.  I have the SW 150ED and I must say it provides impressive views both visually and imaging.  The stock 3.4" focuser works smoothly - not as nice as a FeatherTouch 3.5" - but still very good.  I currently own 2 CFF200mm refractors and have owned many high end refractors - and the SW 150ED continues to impress me.  I especially like the dedicated field flattener and the optional focal reducer - both cover a full size sensor very well.  You could get the SW150ED now and order a TEC or CFF and when either are delivered just sell the SW150ED - for your consideration.

 

Jason

[jeffcrilly2]

Jason - Thx for mentioning the SW 150ED.  

I've been looking into the SW Espirit 150 APO Triplet f/7.    

I didn't realize the Spirit 150 API  existed when I came up with the original list.
But now, I'm quite tempted to pull the trigger on a new one.

 

The Espirit 150  seems to tick most of the boxes.   Also, rings and the flattner are included in the price.   The Reducer is another $500.

I'd like to go with feathertouch because I have feathertouch motors (HSM and PDMS), however optec seems to have a motor for the SW, and I believe the electrical interface for the Optec is the same as the feathertouch HSM.
 

You could get the SW150ED now and order a TEC or CFF and when either are delivered just sell the SW150ED - for your consideration.

 

That is definitely something I've been considering.   Probably the TEC.

 

Re Taks -- I have experience with two of them: FSQ-106n and FS-128.   I'm just not pleased with the focuser on either.  Looks great, but needs maintenance work.   I've done a lot of imaging with the FSQ and some imaging with the FS-128 and they do work superbly, but sadly there is a bit of slop in the Tak focusers.

 

-jeff

Edited by jeffcrilly2, 29 January 2022 - 02:28 AM.