Go Back   IceInSpace > Equipment > Equipment Discussions

Reply
 
Thread Tools Rate Thread
  #21  
Old 05-07-2018, 05:22 PM
rustigsmed's Avatar
rustigsmed (Russell)
Registered User

rustigsmed is offline
 
Join Date: Mar 2012
Location: Mornington Peninsula, Australia
Posts: 3,950
For a bit more wouldn't you go for the ts 130 f7 triplet?

https://www.teleskop-express.de/shop...A-focuser.html -
there is a more expensive one if you want a larger focuser.
Reply With Quote
  #22  
Old 05-07-2018, 05:59 PM
casstony
Registered User

casstony is offline
 
Join Date: Feb 2006
Location: Warragul, Vic
Posts: 4,493
Quote:
Originally Posted by gregbradley View Post
I have used a Tak FS152 before which was fluorite and crown glass element doublet. It was great visually but a bit false colour in images.
Greg.
I wonder if it's a mistake for a fussy imager to try to make one scope do two jobs?

The NP127is might work though?
Reply With Quote
  #23  
Old 05-07-2018, 06:38 PM
glend (Glen)
Registered User

glend is offline
 
Join Date: Jun 2013
Location: Lake Macquarie
Posts: 7,033
Quote:
Originally Posted by rustigsmed View Post
For a bit more wouldn't you go for the ts 130 f7 triplet?

https://www.teleskop-express.de/shop...A-focuser.html -
there is a more expensive one if you want a larger focuser.
Well the question related to Doublets, not Triplets. It does not reflect my personal preference. As a personal preference, yes I would prefer the 130mm FPL-53 Triplet.
Reply With Quote
  #24  
Old 05-07-2018, 06:43 PM
gregbradley's Avatar
gregbradley
Registered User

gregbradley is offline
 
Join Date: Feb 2006
Location: Sydney
Posts: 17,877
Quote:
Originally Posted by rustigsmed View Post
For a bit more wouldn't you go for the ts 130 f7 triplet?

https://www.teleskop-express.de/shop...A-focuser.html -
there is a more expensive one if you want a larger focuser.
Sounds like a nice instrument. FPL53 air spaced triplets were a rare type of scope not that long ago.

How times have changed.

Greg.
Reply With Quote
  #25  
Old 05-07-2018, 06:46 PM
gregbradley's Avatar
gregbradley
Registered User

gregbradley is offline
 
Join Date: Feb 2006
Location: Sydney
Posts: 17,877
Quote:
Originally Posted by rustigsmed View Post
For a bit more wouldn't you go for the ts 130 f7 triplet?

https://www.teleskop-express.de/shop...A-focuser.html -
there is a more expensive one if you want a larger focuser.
Quote:
Originally Posted by casstony View Post
I wonder if it's a mistake for a fussy imager to try to make one scope do two jobs?

The NP127is might work though?
Petsvals as I understand them generally are not good for visual.
My TEC180FL was good at both visual and imaging so not necessarily. But if its a Petsval then yes its more oriented towards imaging and not visual.

I think I am more interested in an APO triplet and F7 with a nice reducer/flattener available.

Greg.

Greg.
Reply With Quote
  #26  
Old 05-07-2018, 07:58 PM
casstony
Registered User

casstony is offline
 
Join Date: Feb 2006
Location: Warragul, Vic
Posts: 4,493
Quote:
Originally Posted by gregbradley View Post
Petsvals as I understand them generally are not good for visual.
Greg.
In terms of planetary viewing the NP's are only marginally behind the Tak doublets and triplets and the NP is designed to be easy to use for visual.

The most noticeable difference between my NP101is and FC100d is depth of focus due to the focal ratio's and the FC is a little more contrasty I think (need to get them side by side on Jupiter again).

An NP127 is a lot pricier than a TS triplet though.


Here's an interesting review: http://doctordreviews.com/4inch-shootout.html
Reply With Quote
  #27  
Old 05-07-2018, 08:07 PM
FlashDrive's Avatar
FlashDrive (Poppy)
Senior Citizen

FlashDrive is offline
 
Join Date: Apr 2008
Location: Bribie Island
Posts: 5,056
Get this one Greg .....

https://www.cloudynights.com/topic/6...ope/?p=8677450

Credit to denis0007dl of CN

Col....
Reply With Quote
  #28  
Old 07-07-2018, 08:00 AM
gregbradley's Avatar
gregbradley
Registered User

gregbradley is offline
 
Join Date: Feb 2006
Location: Sydney
Posts: 17,877
Quote:
Originally Posted by casstony View Post
In terms of planetary viewing the NP's are only marginally behind the Tak doublets and triplets and the NP is designed to be easy to use for visual.

The most noticeable difference between my NP101is and FC100d is depth of focus due to the focal ratio's and the FC is a little more contrasty I think (need to get them side by side on Jupiter again).

An NP127 is a lot pricier than a TS triplet though.


Here's an interesting review: http://doctordreviews.com/4inch-shootout.html
Thanks for that. I thought about a TV NP127i but to be honest I have not seen any spectacular images using that scope. Good ones but not top notch.
I suspect the correction is not as good as it needs to be these days to stand out. If China is putting out respectable air spaced FPL53 triplets for 1/3rd the APM LZOS price then the playing field has changed. Air spaced triplets were only done by TMB/LZOS up to a few years ago.

We also now have FPL 55 glass making its appearance. I am not sure how much better it is over FPL53, I suspect only a little.



Greg.
Reply With Quote
  #29  
Old 07-07-2018, 08:02 AM
gregbradley's Avatar
gregbradley
Registered User

gregbradley is offline
 
Join Date: Feb 2006
Location: Sydney
Posts: 17,877
Here's an interesting review: http://doctordreviews.com/4inch-shootout.html[/QUOTE]

Quote:
Originally Posted by FlashDrive View Post
Get this one Greg .....

https://www.cloudynights.com/topic/6...ope/?p=8677450

Credit to denis0007dl of CN

Col....
hehe.

Greg.
Reply With Quote
  #30  
Old 07-07-2018, 08:14 AM
Atmos's Avatar
Atmos (Colin)
Ultimate Noob

Atmos is offline
 
Join Date: Aug 2011
Location: Melbourne
Posts: 6,980
From what I’ve read FPL-53 has a higher abbe number (closer to fluorite) but FPL-55 is easier to figure and possibly has better mating glasses.
Reply With Quote
  #31  
Old 07-07-2018, 08:30 AM
gregbradley's Avatar
gregbradley
Registered User

gregbradley is offline
 
Join Date: Feb 2006
Location: Sydney
Posts: 17,877
Quote:
Originally Posted by Atmos View Post
From what I’ve read FPL-53 has a higher abbe number (closer to fluorite) but FPL-55 is easier to figure and possibly has better mating glasses.
Yes almost identical Abbe number. Better grinding capability may end up meaning a higher strehl number for the optician to achieve.

Greg.
Reply With Quote
  #32  
Old 07-07-2018, 08:33 AM
LewisM's Avatar
LewisM
Novichok test rabbit

LewisM is offline
 
Join Date: Aug 2012
Location: Somewhere in the cosmos...
Posts: 10,388
With hints at a possible Roland Christen retirement, the end of the GTX-130 line, and a SHORT run of the 92mm Stowaway, if you want anything touched by the hand of Rolando, I'd jump now (though you cannot get on EITHER waiting list as both are closed).

Otherwise, the Tak 120 is VERY hard to beat, except with the TOA 130 (which is, for all intents and purposes, perfect).
Reply With Quote
  #33  
Old 07-07-2018, 08:37 AM
gregbradley's Avatar
gregbradley
Registered User

gregbradley is offline
 
Join Date: Feb 2006
Location: Sydney
Posts: 17,877
Quote:
Originally Posted by Atmos View Post
From what I’ve read FPL-53 has a higher abbe number (closer to fluorite) but FPL-55 is easier to figure and possibly has better mating glasses.
Quote:
Originally Posted by LewisM View Post
With hints at a possible Roland Christen retirement, the end of the GTX-130 line, and a SHORT run of the 92mm Stowaway, if you want anything touched by the hand of Rolando, I'd jump now (though you cannot get on EITHER waiting list as both are closed).

Otherwise, the Tak 120 is VERY hard to beat, except with the TOA 130 (which is, for all intents and purposes, perfect).
Yes I am on both of those lists. The AP 130GTX list I got on very early.

I can see those 2 Tak offerings are very nice. The TOA though is often said to be heavy and front heavy at that. Not sure if that is a real problem in use though. Too bad they don't do a TOA110. That would be nice.

The Tak 120 does sound nice. The offerings are odd though in that the TSA line is 102 and 120 and TOA is 130 and 150. I wonder if there is a reason for that other than marketing and a change of direction.

Greg.
Reply With Quote
  #34  
Old 07-07-2018, 12:32 PM
LewisM's Avatar
LewisM
Novichok test rabbit

LewisM is offline
 
Join Date: Aug 2012
Location: Somewhere in the cosmos...
Posts: 10,388
TSA line is ONLY 120 now - the 102 has been out of production a few years now, replaced - oddly - with the FC-100 (not a wise Tak choice to cancel the 102 IMHO, as it was THE best 4" scope I have ever owned or used). I expect the FC-100 sells better, being considerably cheaper than the 102 ever was.

The design of the TSA is pure triplet, whereas the TOA is well-spaced triplet. The new fluorite FOA shares the same design principle, and is one of the highest Strehl production scopes ever made (it's for all intents and purposes a poly-Strehl of 0.995)
Reply With Quote
  #35  
Old 07-07-2018, 12:46 PM
beren
Registered User

beren is offline
 
Join Date: Oct 2004
Posts: 2,810
Its a shame Tak don't have a "F" version of the TSA-120 with the larger focuser like the TOA-130. For visual its fine but hate the TSA-120 focuser for imaging, tried a few electronic focusers like robofocus and nothing worked when I had the large STT-8300.
Reply With Quote
  #36  
Old 07-07-2018, 12:58 PM
Merlin66's Avatar
Merlin66 (Ken)
Registered User

Merlin66 is offline
 
Join Date: Oct 2005
Location: Junortoun Vic
Posts: 8,904
I use for visual an original TV Genesis.....amazing!
Certainly nothing wrong with the TV Petzval designs.
Reply With Quote
  #37  
Old 07-07-2018, 01:01 PM
gregbradley's Avatar
gregbradley
Registered User

gregbradley is offline
 
Join Date: Feb 2006
Location: Sydney
Posts: 17,877
Quote:
Originally Posted by LewisM View Post
TSA line is ONLY 120 now - the 102 has been out of production a few years now, replaced - oddly - with the FC-100 (not a wise Tak choice to cancel the 102 IMHO, as it was THE best 4" scope I have ever owned or used). I expect the FC-100 sells better, being considerably cheaper than the 102 ever was.

The design of the TSA is pure triplet, whereas the TOA is well-spaced triplet. The new fluorite FOA shares the same design principle, and is one of the highest Strehl production scopes ever made (it's for all intents and purposes a poly-Strehl of 0.995)
Thanks Lewis. I wondered why I could only find the TSA120 listed.
What's with the tiny focuser and no dual speed at US$4430?

First thing would be to throw out the focuser and put a Feathertouch on it.

FOA is only the 60mm right? Sounds good but very small aperture.

If they could make a 110mm FOA it would be attractive.

Greg.
Reply With Quote
  #38  
Old 07-07-2018, 01:04 PM
gregbradley's Avatar
gregbradley
Registered User

gregbradley is offline
 
Join Date: Feb 2006
Location: Sydney
Posts: 17,877
Quote:
Originally Posted by LewisM View Post
TSA line is ONLY 120 now - the 102 has been out of production a few years now, replaced - oddly - with the FC-100 (not a wise Tak choice to cancel the 102 IMHO, as it was THE best 4" scope I have ever owned or used). I expect the FC-100 sells better, being considerably cheaper than the 102 ever was.

The design of the TSA is pure triplet, whereas the TOA is well-spaced triplet. The new fluorite FOA shares the same design principle, and is one of the highest Strehl production scopes ever made (it's for all intents and purposes a poly-Strehl of 0.995)
Quote:
Originally Posted by beren View Post
Its a shame Tak don't have a "F" version of the TSA-120 with the larger focuser like the TOA-130. For visual its fine but hate the TSA-120 focuser for imaging, tried a few electronic focusers like robofocus and nothing worked when I had the large STT-8300.
Yes it was the first thing I noticed about the scope, the tiny focuser. It would only handle small sensored cameras. Plus no dual speed ?? uuhhh what? Every scope I have seen recently listed has a dual speed focuser - every single one.

But then a lot of scopes need their focusers replaced. Too bad Tak doesn't sell OTAs with no focuser!! haha.

FC100 I take it is a fluorite doublet. It replaces the FS102?


Greg.
Reply With Quote
  #39  
Old 07-07-2018, 01:11 PM
Atmos's Avatar
Atmos (Colin)
Ultimate Noob

Atmos is offline
 
Join Date: Aug 2011
Location: Melbourne
Posts: 6,980
Quote:
Originally Posted by gregbradley View Post

FC100 I take it is a fluorite doublet. It replaces the FS102?
The main difference between the FS102 and the FC100 range is that the FS102 had the fluorite element at the front where as the FC100 has the fluorite element at the rear. The FS series may have also been a bit beefier.
Reply With Quote
  #40  
Old 07-07-2018, 01:45 PM
LewisM's Avatar
LewisM
Novichok test rabbit

LewisM is offline
 
Join Date: Aug 2012
Location: Somewhere in the cosmos...
Posts: 10,388
Quote:
Originally Posted by beren View Post
Its a shame Tak don't have a "F" version of the TSA-120 with the larger focuser like the TOA-130. For visual its fine but hate the TSA-120 focuser for imaging, tried a few electronic focusers like robofocus and nothing worked when I had the large STT-8300.
Stuart,

You can buy the 4" focuser directly from Tak and fit it to the TSA-120 directly - both share the 125mm tube.

Cost is...well... so FT may be a better option lol.

I personally find the Tak focuser just fine. Fitting the dual speed add on is so simple too, and not expensive (the FSQ-106ED's of course come dual speed as standard, unlike the old N model)
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 10:00 PM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Advertisement
Testar
Advertisement
Bintel
Advertisement