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TEC 140FL

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#1 Marcus Roman

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Posted 22 July 2019 - 03:13 AM

Hello dear friends, I'm interested in knowing opinions about the new TEC 140FL from people who had the opportunity to look through...also, if anyone can compare her/his feeling to previous TEC 140ED or to other premium 5/5,5" apos (Taka FS128 etc.)...


Edited by Marcus Roman, 22 July 2019 - 03:13 AM.


#2 Stelios

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Posted 22 July 2019 - 03:28 AM

Moving to refractors for a better fit.


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#3 Marcus Roman

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Posted 22 July 2019 - 03:57 AM

Moving to refractors for a better fit.

Thanks!!!



#4 flyingcougar

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Posted 22 July 2019 - 04:17 AM

Jeff B did a pretty extensive evaluation between the FL and ED a few pages into this thread:

 

https://www.cloudyni...age-4?hl= 140fl


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#5 Marcus Roman

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Posted 22 July 2019 - 05:15 AM

Jeff B did a pretty extensive evaluation between the FL and ED a few pages into this thread:

 

https://www.cloudyni...age-4?hl= 140fl

Thanks! I read it and I understand that  at least this first release samples are not superior to the ED version...just wondering which 140mm apo I want to address to...



#6 cytan299

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Posted 22 July 2019 - 05:39 AM

Hi guys,

   Another question is whether the 140FL is optimized for AP, i.e. does this new design minimize the infamous blue bloat that is seen in the 140 ED when used for AP? Or a field flattener is still necessary for AP?

 

cytan


Edited by cytan299, 22 July 2019 - 06:04 AM.


#7 Scott99

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Posted 22 July 2019 - 09:15 AM

the purpose of a field flattener is to correct field curvature, not chromatic aberration.   All refractors with normal (closely-spaced) objective lenses have inherent field curvature that must be corrected with a flattener optic for imaging.

 

Have you guys read the design specifications and information from TEC?   That's the best place to start IMO.   The specs in Yuri's humorous "wings of strehl" post delineate the differences between the ED and FL versions quite clearly.

 

https://groups.io/g/...20,2,0,27329759


Edited by Scott99, 22 July 2019 - 09:26 AM.

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#8 Element79

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Posted 22 July 2019 - 10:02 AM

Hi guys,

   Another question is whether the 140FL is optimized for AP, i.e. does this new design minimize the infamous blue bloat that is seen in the 140 ED when used for AP? Or a field flattener is still necessary for AP?

 

cytan

 

I think that the design of the TEC140FL is for general purpose use and not optimized for one or the other.  TEC makes a dedicated field flattener for this scope for imagers that threads into the Feathertouch focuser.  I think that the one designed for the 140FL also reduces the focal ratio a bit but I may be wrong about that.  I am strictly a visual user.

 

Several weeks ago when I was testing mine I couldn't detect any violet haze at all even looking at bright objects, but then again my eyes are old and are probably not capable of seeing as far into the violet spectrum as they could when I was younger...

 

The TEC140FL is definitely a very nice scope but the TEC140ED was excellent too.


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#9 cytan299

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Posted 22 July 2019 - 11:50 AM

the purpose of a field flattener is to correct field curvature, not chromatic aberration.   All refractors with normal (closely-spaced) objective lenses have inherent field curvature that must be corrected with a flattener optic for imaging.

 

Have you guys read the design specifications and information from TEC?   That's the best place to start IMO.   The specs in Yuri's humorous "wings of strehl" post delineate the differences between the ED and FL versions quite clearly.

 

https://groups.io/g/...20,2,0,27329759

Hi Scott,

   I've read the TEC group, and that question has been asked about whether the 140FL has the blue bloat feature (because the 140FL may still be optimized for visual) or not, but I don't believe Yuri has given an answer. Please correct me if I'm wrong.

 

    There are other posts that claim that the FF will shift the blue to reduce or fix the bloat:

 

https://www.cloudyni...ts-for-tec-140/

 

and here

 

http://www.astrosurf...ent/apo140e.htm

 

I'd like to know because I'm choosing between getting a TEC140FL or a TOA130NFB. I'd really like to get the 140FL because it is a lot lighter than the TOA130.

 

So, is it necessary to get the FF? 

 

cytan


Edited by cytan299, 22 July 2019 - 11:54 AM.


#10 marcus_z

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Posted 22 July 2019 - 12:01 PM

So, is it necessary to get the FF?

I bet a Skywatcher with FF performs better than a TEC without FF...

#11 peleuba

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Posted 22 July 2019 - 12:20 PM

 

Several weeks ago when I was testing mine I couldn't detect any violet haze at all even looking at bright objects, but then again my eyes are old and are probably not capable of seeing as far into the violet spectrum as they could when I was younger...

 

 

 

Glad you got your telescope.

 

"Blue boat" in this context does not refer to visual, but, rather imaging where stars look larger with blue halos in photos.  This occurs because of unfocused light at the ends of the spectrum. and is only visible in longer exposure CCD/CMOS imaging - film too, if anyone still uses it.

 

The "Wings of Strehl" that Scott linked to are, I believe, design parameters and goals based on exact melt data and a perfect lens figure of a TEC140FL.  Basically its a theoretical representation of a perfect lens.  Actual production will be slightly different, but TEC is a very good company and production will be close to design.  "Wings of Strehl graphs do seem to show that there will be better correction (at least theoretically) at the ends of the spectrum, too, leading to a higher polychromatic Strehl.  But I am not sure this has been fully realized after seeing Jeff's TEC140ED vs TEC140FL autocollimation tests in double pass.


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#12 starryhtx

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Posted 22 July 2019 - 01:34 PM

The TEC "never in stock" 40 would be a great scope if you can get one!



#13 Scott99

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Posted 22 July 2019 - 02:03 PM

The TEC "never in stock" 40 would be a great scope if you can get one!

I just ordered one last month and it's expected within a week or two.   My TEC110 was an excellent scope so I ordered a larger TEC.  They will sell one to anyone with cash - give it a try!  laugh.gif

 

Field flatteners are photographic correctors and are not used visually.  From the specs of the lens design I see excellent color correction across the board.  I expect the scope to be excellent for visual use and imaging.   From the info TEC posted it seems clear that any unfocused blue in imaging or visual will be reduced from the ED version, if not completely eliminated.


Edited by Scott99, 22 July 2019 - 02:06 PM.

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#14 3 i Guy

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Posted 22 July 2019 - 02:05 PM

The TEC "never in stock" 40 would be a great scope if you can get one!

Since you keep beating that dead horse, let me spell it out for you. Tec 140’s will never be “in stock”. The glass used to make them ain’t cheap. Why would Yuri make more in a production run than he has orders for? If you want “in stock”, buy a Tak, Chinese, or put up a wanted ad. This is about as close to “in stock” as you’re ever going to find.

 

Tec 140


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#15 vahe

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Posted 22 July 2019 - 02:35 PM

For those who are disappointed for the current long wait time of TEC scopes, here is a very old post by Roland, somewhat related to this subject.

(It is from post #10968 on the old tec-scopes Yahoo Groups).

 

"In the year 2001 I was in my 20th year making telescopes, accessories and apo lenses. I also had only 3-6 month wait the first 5-8 years but that changed as apos became popular. So now I am 5 years behind  in my 25th year of 2006. I predict that Yuri will be an additional 1 year behind every 5 years that he is in business (extra opticians do not grow on trees and are just about impossible to train from scratch in a small company environment). In fact, I would bet that for  some of his products, like his large Maks, he is already more than 1 year behind and has had to drop some due to production constraints, just like me.

.

So, we will see down the road. Meanwhile, don't hesitate to load up his schedule because the longer you wait, the longer you will wait."

.

Vahe


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#16 Heywood

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Posted 22 July 2019 - 03:05 PM

I just ordered one last month and it's expected within a week or two. My TEC110 was an excellent scope so I ordered a larger TEC. They will sell one to anyone with cash - give it a try! laugh.gif

Field flatteners are photographic correctors and are not used visually. From the specs of the lens design I see excellent color correction across the board. I expect the scope to be excellent for visual use and imaging. From the info TEC posted it seems clear that any unfocused blue in imaging or visual will be reduced from the ED version, if not completely eliminated.


From whom did you order the 140FL???

#17 Heywood

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Posted 22 July 2019 - 03:07 PM

Since you keep beating that dead horse, let me spell it out for you. Tec 140’s will never be “in stock”. The glass used to make them ain’t cheap. Why would Yuri make more in a production run than he has orders for? If you want “in stock”, buy a Tak, Chinese, or put up a wanted ad. This is about as close to “in stock” as you’re ever going to find.

Tec 140


I've always wondered how Takahashi manages to keep its telescopes in stock.
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#18 payner

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Posted 22 July 2019 - 03:23 PM

They do keep their refractors in stock, but the Mewlons, at least the 250CRS and 300CRS, you'll typically wait on those.

 

Randy



#19 starryhtx

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Posted 22 July 2019 - 03:37 PM

Since you keep beating that dead horse, let me spell it out for you. Tec 140’s will never be “in stock”. The glass used to make them ain’t cheap. Why would Yuri make more in a production run than he has orders for? If you want “in stock”, buy a Tak, Chinese, or put up a wanted ad. This is about as close to “in stock” as you’re ever going to find.

 

Tec 140

Maybe you could sell him yours since there's a 5 year wait.



#20 cytan299

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Posted 22 July 2019 - 03:55 PM

I just ordered one last month and it's expected within a week or two.   My TEC110 was an excellent scope so I ordered a larger TEC.  They will sell one to anyone with cash - give it a try!  laugh.gif

 

Field flatteners are photographic correctors and are not used visually.  From the specs of the lens design I see excellent color correction across the board.  I expect the scope to be excellent for visual use and imaging.   From the info TEC posted it seems clear that any unfocused blue in imaging or visual will be reduced from the ED version, if not completely eliminated.

So, do you mean no FF is required for 140FL to correct the blue bloat?

 

cytan


Edited by cytan299, 22 July 2019 - 03:58 PM.


#21 Salacious B Crumb

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Posted 22 July 2019 - 04:34 PM

The TEC140FL is definitely a very nice scope but the TEC140ED was is excellent too... ;  )

 

Sorry, couldn't resist to correct this as I recently bought a 16 years old ED and just love it. If FL's would be stock items, I would have bought one but I'm way too impatient to wait for years to get one.

 

 

- Mikko


Edited by Salacious B Crumb, 22 July 2019 - 04:37 PM.

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#22 Scott99

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Posted 22 July 2019 - 06:13 PM

From whom did you order the 140FL???

Anacortes -and they have another one ready to go within a month - click on the link from 3iGuy above.

 

Looks like a 160FL is also available there on short notice.  It's nice that TEC sells some scopes through dealers at the same price as direct order...provides another option for procrastinators and last-minute deciders like me


Edited by Scott99, 22 July 2019 - 06:14 PM.

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#23 pbunn

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Posted 23 July 2019 - 02:49 PM

Got mine from Tolga. He usually has one in the que. I bought my 140ED from Anacortes.



#24 Jeff B

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Posted 23 July 2019 - 03:00 PM

My advice is this.

 

If you want the FL version, cough up the down payment, then go shopping for a used ED.  Should take you only a week or two to find one.

 

Happily use the ED until the FL is ready, then sell the ED.

 

If you find you like the ED enough to forgo the FL, then cancel your order.

 

Visually, I found both scopes quite sharp.  The differences I did find visually were rather trivial.  For visual.

 

Jeff


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#25 rob.0919

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Posted 23 July 2019 - 05:51 PM

I just ordered one last month and it's expected within a week or two.   My TEC110 was an excellent scope so I ordered a larger TEC.  They will sell one to anyone with cash - give it a try!  laugh.gif

Seriously ??

 

I've just at the one year mark since i put my deposit down.

But my wait is nearly over.......




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