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Room for a Sky Watcher 140mm ED doublet?

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#1 25585

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Posted 21 July 2019 - 05:42 PM

As known 150s are big beasts. 

 

In all their refractor ranges, Sky Watcher jump from 120mm to 150mm. 4.5" to 6".

 

I woud like a 135 to 140mm doublet, in the ED Pro range, a lower cost alternative to APM's 140mm doublet. Lighter so a larger mount is not required, but 20mm more aperture than a 120mm.

 

How do you all feel about a SW 140mm ED Pro doublet?



#2 junomike

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Posted 21 July 2019 - 06:03 PM

A 140ED using the same glass as the APM 140 and 120ED won't be much cheaper then the APM 140ED.

I think SW realizes that the 140mm market is already crowded.



#3 ris242

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Posted 21 July 2019 - 09:20 PM

A 140ED using the same glass as the APM 140 and 120ED won't be much cheaper then the APM 140ED.

I think SW realizes that the 140mm market is already crowded.

 

Please tell me of all the other 140ED doublet brands so I can research the overcrowded market. :)


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#4 Starlease

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Posted 21 July 2019 - 09:35 PM

It needs to be longer focal length for us visual guys say 1200mm.


Edited by Starlease, 21 July 2019 - 09:35 PM.

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#5 fred1871

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Posted 21 July 2019 - 11:05 PM

One obvious 140 that has NOT been made would be Vixen producing an ED version of the NA 140, an achromat that increasingly looks out of place given the pricing these days compared to ED doublets. The NA 140 is a 4-element Petzval design, flat field and short focal length/focal ratio resulting from the reducing effect of the Petzval doublet. So the objective is longer ratio, hence less CA, than the final f5.7 suggests. But it's still an achromat.

 

I have one, have learned to live with some CA or reduce it with filters (Baader Fringe-Killer general use, Baader Semi-Apo for lunar and planetary).

 

But I suspect Vixen pricing would make an ED version not very successful in the marketplace. And the APM 140 by using FPL53 has offered a doublet of very good colour correction without charging the price that might be expected for a scope that visually seems to do it all very well indeed.

 

I'd think there is a place for a SkyWatcher 140 ED for the folk who want less weight and length than a 150 but more light and resolution than a 120. Some of us like that particular size as a good overall compromise. As with the SW 120 ED, I'd think it would need to have the best glass to be competitive given the rather basic mechanical features of the lower priced SW scopes.


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#6 tonyt

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Posted 22 July 2019 - 12:00 AM

I think Skywatcher made an obvious mistake bringing out the 150 f/8 rather than a 140 f/7. I bet APM sells more 140's than 152's.


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#7 SeattleScott

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Posted 22 July 2019 - 02:08 AM

The beauty of a 140 F7 doublet is you could put it on a medium duty mount. I know they say that about the 150 doublets, but I’m not convinced based on my AR6. Granted my AR6 has satisfactory stability on my SXW. But I’m not exactly cranking it up on the Moon and planets.

Scott
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#8 25585

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Posted 22 July 2019 - 05:03 AM

Please tell me of all the other 140ED doublet brands so I can research the overcrowded market. smile.gif

Exactly. 

 

CFF is a triplet & expensive

TEC is a triplet & expensive 

ES is a triplet, pricey

Vixen is an achro, possibly discontinued.

APM is a doublet

 

SW with the same form factor as their other ED Pros, i.e. downmarket, could market an entry level 140mm, at a lower price than the APM.

 

The 140mm market is undercrowded, and currently a single 140 doublet, and single mainstream triplet are all. 


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#9 CHASLX200

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Posted 22 July 2019 - 05:07 AM

If anything go 175mm.



#10 SeattleScott

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Posted 22 July 2019 - 08:18 AM

That ain’t gonna ride on my mount. Completely different market segment by adding 35mm. Might sell, but not to people wanting a 140.

Scott

Edited by SeattleScott, 22 July 2019 - 08:19 AM.

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#11 watchplanets

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Posted 22 July 2019 - 09:38 AM

a 140ed may be ok for those that don't want the 150ed but what could they make it for?

the 150ed is like 3100 plus tax = 3500

the 120ed is 2539 plus tax = 2869

 

that's only a 630 difference half price point is 315 more then 120ed is this worth them making another one tho??


Edited by watchplanets, 22 July 2019 - 09:39 AM.


#12 Bomber Bob

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Posted 22 July 2019 - 11:04 AM

I know they say that about the 150 doublets, but I’m not convinced based on my AR6.

 

I've abandoned my plan to put the same Meade StarFinder mount that I use on a pedestal with my APM 152ED onto a hefty wood tripod, because it won't be anywhere near the same as my 4" fracs on their tripod EQs.  I can make this platform stable, but the overall weight...  Yikes!  It would be portable, but there wouldn't be any toting the assembled rig around the back yard.

 

I've already bought the 152ED, but a better APO aperture progression for me would've been:  My current 50mm & 80mm fluorites, plus a 110mm ED, with a 140mm ED as my largest.  No regrets with my 152, but it really needs an observatory -- that's the only way I'd get to use it on work nights.  Black Friday 2017, APM had the 152 down to 140 prices, and I debated until about the last possible minute before clicking the BUY button.

 

OP, I get where you're coming from.  APM sells some great scopes, but if you're primarily a visual observer (like me) will you get your money's worth with their 140?  IDK.  I do know that I wouldn't have paid more than $3000 for my 152, even if I got to use it more often -- and it's my best-performing planetary scope.

 

Is the 140mm ED field crowded?  Maybe it's the case that there's not enough demand.  I jumped at the chance to own a manageable 6" refractor, and I'm not alone in that group of buyers.  Wish I could have a private convo with the vendors, who must know which apertures are most sought.


Edited by Bomber Bob, 22 July 2019 - 11:06 AM.


#13 Richard Whalen

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Posted 22 July 2019 - 11:13 AM

A 140 would be nice, but would only interest me if it was f12 and better than 1/8 wave P-V and 1/50 wave rms. 



#14 jay.i

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Posted 22 July 2019 - 11:19 AM

I don't believe there is room in the Evostar ED lineup for a 140mm doublet.
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#15 skyward_eyes

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Posted 22 July 2019 - 11:42 AM

When we first looked at doing something larger than the 120 we pitched a 140mm size. Over the years of design we moved up to the 150 instead. At this point I don't think we will be adding a 140. 


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#16 Jon Isaacs

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Posted 22 July 2019 - 11:53 AM

As known 150s are big beasts. 

 

In all their refractor ranges, Sky Watcher jump from 120mm to 150mm. 4.5" to 6".

 

I woud like a 135 to 140mm doublet, in the ED Pro range, a lower cost alternative to APM's 140mm doublet. Lighter so a larger mount is not required, but 20mm more aperture than a 120mm.

 

How do you all feel about a SW 140mm ED Pro doublet?

 

120 mm = 4.72".

 

140mm is not going to a one trip out the door refractor.. might as well be a 150 mm

 

Jon



#17 dweller25

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Posted 22 July 2019 - 11:58 AM

Perhaps a different Skywatcher doublet ED marketing strategy would have been 80, 100, 120, 140, 160 ?



#18 watchplanets

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Posted 22 July 2019 - 12:07 PM

160 is too big for most people the 152 is prob as big as most will want, I mean in this thread its about smaller then the 150ed



#19 evan9162

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Posted 22 July 2019 - 12:16 PM

APM 140 vs 152 sales...

I've seen 152 serial numbers in the high 200s.  The highest SN I've seen for the 140 is in the 170s.  I think the 152 far outsells the 140 - the 140 is a bit of a niche product...



#20 Heywood

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Posted 22 July 2019 - 01:24 PM

I know they say that about the 150 doublets, but I’m not convinced based on my AR6.

I've abandoned my plan to put the same Meade StarFinder mount that I use on a pedestal with my APM 152ED onto a hefty wood tripod, because it won't be anywhere near the same as my 4" fracs on their tripod EQs. I can make this platform stable, but the overall weight... Yikes! It would be portable, but there wouldn't be any toting the assembled rig around the back yard.

I've already bought the 152ED, but a better APO aperture progression for me would've been: My current 50mm & 80mm fluorites, plus a 110mm ED, with a 140mm ED as my largest. No regrets with my 152, but it really needs an observatory -- that's the only way I'd get to use it on work nights. Black Friday 2017, APM had the 152 down to 140 prices, and I debated until about the last possible minute before clicking the BUY button.

OP, I get where you're coming from. APM sells some great scopes, but if you're primarily a visual observer (like me) will you get your money's worth with their 140? IDK. I do know that I wouldn't have paid more than $3000 for my 152, even if I got to use it more often -- and it's my best-performing planetary scope.

Is the 140mm ED field crowded? Maybe it's the case that there's not enough demand. I jumped at the chance to own a manageable 6" refractor, and I'm not alone in that group of buyers. Wish I could have a private convo with the vendors, who must know which apertures are most sought.


I've heard from one vendor that sales of the 150 are good but not fabulous, as one would expect. It is a niche instrument. It seems that most folks want small refractors these days.

#21 watchplanets

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Posted 22 July 2019 - 01:35 PM

I've heard from one vendor that sales of the 150 are good but not fabulous, as one would expect. It is a niche instrument. It seems that most folks want small refractors these days.

well for me when this issue came out like 2 years ago, I voted for a 6' f/7 or MAX 7.5

 

the 6" f/8 is just too long want something more portable and lighter weight heck celestron was first to come out with a cheap 6" acro from what I recall in 98 or 99. then meade, skywatcher, Antares galeio, now ES. however f/8 is just too long I know some will say a f/7 or f/7.5 is not much shorter BUT theres already a limit what I think a lot people want as far as light weight and portabililty, and the f/8 is just too long.

 

To me my perfect would be a 6" f7 or max 7.5 but with 53 glass to compensate the colour



#22 Doug Culbertson

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Posted 22 July 2019 - 01:43 PM

APM 140 vs 152 sales...

I've seen 152 serial numbers in the high 200s.  The highest SN I've seen for the 140 is in the 170s.  I think the 152 far outsells the 140 - the 140 is a bit of a niche product...

According to Markus Ludes in this thread, he had sold 163 152EDs on September 27, 2015, while he received the first example of the 140ED on August 22, 2015. That means that the 152ED had a pretty good head start on the 140. While the 152ED may very well outsell the 140, I don’t think that one can determine this based on serial numbers. 



#23 ris242

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Posted 22 July 2019 - 01:53 PM

If I have a decent 100mm, a 120mm doesn’t seem a big jump.

A 140 is almost the same length.....so as long as the mount can take it, it seems a good place to go.

i would lose on FL so planets are smaller against a 150.

could add a reducer to brighten widen fields for dso

 

is the issue with a 150mm - the weight or the length?

if it’s weight a 130mm f9.23 would give great views at a much higher price.

if it’s length, you go 140?



#24 25585

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Posted 22 July 2019 - 01:53 PM

a 140ed may be ok for those that don't want the 150ed but what could they make it for?

the 150ed is like 3100 plus tax = 3500

the 120ed is 2539 plus tax = 2869

 

that's only a 630 difference half price point is 315 more then 120ed is this worth them making another one tho??

But more sales of a 140 because one can ride on a decent 120's mount. No extra expense or hassle as Chas & others had. THAT saving is signifigant! 



#25 watchplanets

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Posted 22 July 2019 - 02:05 PM

But more sales of a 140 because one can ride on a decent 120's mount. No extra expense or hassle as Chas & others had. THAT saving is signifigant! 

I use my eq5 for both and its more then fine,i do miss when the lxd75 and asgt came with a real 2" steel legs now almost all mounts under 1500 is 1.75 which ok but 2" was much better




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