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  #21  
Old 12-07-2013, 11:23 AM
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Second, quality of eyepiece does make a big difference. You need to be consistent the whole way through with the optical path. Probably the absolute best eyepiece for the 'specific' parameter of light pass/contrast are the Pentax XWs. There are many other excellent eyepieces which are superior on other attributes but for this specific variable in viewing DSOs through a refractor I found the XWs to be best.
Hadn't considered that so much as the scope itself. Next time I get away from the city I'll need to redo my side-by-side using my 21mm Pentax XL instead of the 22mm Panoptic.
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  #22  
Old 12-07-2013, 12:42 PM
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Peter I would put my Istar 127mm f8 achro up against your TV85 on Saturn any day , the Istar would win in every way .
that's my opinion .
As would any 120mm Ed doublet on the market today .
I find the 120mm class refractors to be the best all round scopes , size/performance ratio . .
Brian.
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  #23  
Old 12-07-2013, 12:57 PM
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Hadn't considered that so much as the scope itself. Next time I get away from the city I'll need to redo my side-by-side using my 21mm Pentax XL instead of the 22mm Panoptic.

Sorry Morton - XLs don't use Lanthanum glass - only the XWs. The XL are akin to the Pans so I wouldn't expect much of a difference between them in light pass/contrast.
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  #24  
Old 12-07-2013, 12:58 PM
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Originally Posted by brian nordstrom View Post
Peter I would put my Istar 127mm f8 achro up against your TV85 on Saturn any day , the Istar would win in every way .
that's my opinion .
As would any 120mm Ed doublet on the market today .
I find the 120mm class refractors to be the best all round scopes , size/performance ratio . .
Brian.
Well your Istar isn't exactly your average achro, is it?

But the OP's question is about comparing a 120ED-type scope against his existing 6" Mak. I came across a post on Cloudy Nights the other night where someone did this comparison and said they were about the same in terms of image brightness. But obviously different animals when you consider portability, resolving power, etc.

Then there's the actual optical quality of the scopes being compared. Is a Skywatcher 120ED as "good" as an Intes MK-65? I don't know.

Personally I'd like both!
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  #25  
Old 12-07-2013, 01:02 PM
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Sorry Morton - XLs don't use Lanthanum glass - only the XWs. The XL are akin to the Pans so I wouldn't expect much of a difference between them in light pass/contrast.
Thanks. Didn't know that. Must compare the XL and Pan when I get the chance.
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  #26  
Old 12-07-2013, 01:06 PM
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" Peter I would put my Istar 127mm f8 achro up against your TV85 on Saturn any day , the Istar would win in every way .
that's my opinion ."

This is an example of the problem - I am not speculating/espousing my opinions of what might be but empirically reporting my direct observations of a TV-85 versus the other specified refractors. The Vixen 102M is an absolutely superb f/10 planet killer with 100% Japanese glass - but the TV-85 still beat it providing a superior crisp, clearly resolved image of Saturn.

As far as planetary observing at high magnification is concerned I am doubtful any achro under f/12 will rival a top shelf APO - but rather than affirm a view I will accept the challenge and next time I am in Darwin we can see for ourselves.
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  #27  
Old 12-07-2013, 04:08 PM
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re

Buddy if i can help.Even v good refr. Will NOT break the laws of physic, optics.Legendery status is quite often just a marketing ploy,to suck in the inexperienced and gullible.Slightly sharper image yes but a Properly cooled mak around7" mark would kill it for resolution as would a 9 1/4 sct.just depends what your expectations are.Waste of money in my view!
Now if it where one of the other scopes mentioned.wow! Ill probably end up with a 7/8 mak myself!
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  #28  
Old 12-07-2013, 04:35 PM
PeterHA (Peter)
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So that is what I am going to do

All,

Thanks for all you valuable input.

After this input from a variety of people I have come to the following conclusion:


For now I will keep on going with my Mak, but I will address the shortcomings:
  • Change the focuser to a Crayford style (lookig for a used one to adapt) as the helical + extension (plug-in not sliding) is a pain
  • Store the scope dust protected in a location closer to ambient temperatur to get quicker cool down
Long term I will try to direct compare to a 120 ED, one member has offered via PM.
Depending on what this comparison shows I will either be happy with my Mak or hunt for a 120mm ED or try to have a look through a premium 120 APO.

Cheers,

Peter
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  #29  
Old 12-07-2013, 04:52 PM
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Originally Posted by bigjoe View Post
Buddy if i can help.Even v good refr. Will NOT break the laws of physic, optics.Legendery status is quite often just a marketing ploy,to suck in the inexperienced and gullible.Slightly sharper image yes but a Properly cooled mak around7" mark would kill it for resolution as would a 9 1/4 sct.just depends what your expectations are.Waste of money in my view!
Now if it where one of the other scopes mentioned.wow! Ill probably end up with a 7/8 mak myself!

Joe - I am specifically talking about a smallish high end APO refractor vs a larger Achro on bright object viewing such as planetary observing at high magnification - I am not commenting on a Mak for DSO etc
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  #30  
Old 12-07-2013, 05:08 PM
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Originally Posted by PeterHA View Post
For now I will keep on going with my Mak, but I will address the shortcomings:
  • Change the focuser to a Crayford style (lookig for a used one to adapt) as the helical + extension (plug-in not sliding) is a pain
I bought my MK-67 a Moonlite CR focuser for its 10th anniversary

They have an adapter plate for the MK-65 as well, all you need to find is a 2nd hand CR (Newtonian) focuser.

Cheers
Steffen.
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  #31  
Old 12-07-2013, 05:44 PM
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Prof.Focusing and cooling are critical withh these maks, scts.Esp maks thats why it appears, quite often that a smallish ed will beat them on planetary.A little bit blobbier
Etc A new focuser os almost a given!
But point taken. For quick views etc you cant beat good 80/ 120ish glass.But my preference is some apperture as other people as well as myself want to actually see resolution on globs and say wow!, and not say" i cant see a thing"?esp now near the zenith in sydney,plenty to see.Cheers.PS: Hope you and all are well and prospering.
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  #32  
Old 12-07-2013, 06:05 PM
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Originally Posted by Profiler View Post
" Peter I would put my Istar 127mm f8 achro up against your TV85 on Saturn any day , the Istar would win in every way .
that's my opinion ."
Profiler - Saturn as an example of comparative performance between Acros and Apos is a classic red herring for an example . Saturn is fairly monochromatic (yellow ) in colour and looked good at high power in my Chinese 6" F8 achro where as Jupiter was bathed in false colour. On Saturn I would certainly expect your 127 Achro to outgun an 85mm Apo....

Re 120 ED quality - my Orion Epoch 120 ED F7.5 shows a perfect star test and no false colour , I doubt a very high end APO will show a significant improvement on that to justify 2 or 3 times the expenditure.
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  #33  
Old 12-07-2013, 06:19 PM
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Hi Joe

Yes - good to hear from you as well and hope you are getting some time under the stars in between the LP. What are you using these days?
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  #34  
Old 12-07-2013, 06:32 PM
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Originally Posted by Satchmo View Post
Profiler - Saturn as an example of comparative performance between Acros and Apos is a classic red herring for an example . Saturn is fairly monochromatic (yellow ) in colour and looked good at high power in my Chinese 6" F8 achro where as Jupiter was bathed in false colour. On Saturn I would certainly expect your 127 Achro to outgun an 85mm Apo....

Re 120 ED quality - my Orion Epoch 120 ED F7.5 shows a perfect star test and no false colour , I doubt a very high end APO will show a significant improvement on that to justify 2 or 3 times the expenditure.

Hopefully this isn't speculation and based on actual observations with top end TVs, APs and Taks.

I think it best to simply conclude that we agree to disagree. I have lost count how many cheap and expensive refractors I have personally compared over the years but if money isn't an issue I know which are, from my actual observatons, better.

I just can't comprehend how so many people (including myself) around the world are apparently hoodwinked into wasting money buying high end refractors or how companies such as TV, AP and Tak can possibly stay in business if any of these mass produced Chinese scopes or Achros were anywhere as good.

Why would anyone bother spending almost 5k on a TSA-120 if a SW BD120 for approx. 2k was just as good
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  #35  
Old 12-07-2013, 06:45 PM
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Originally Posted by PeterHA View Post
All,

Thanks for all you valuable input.

After this input from a variety of people I have come to the following conclusion:

For now I will keep on going with my Mak, but I will address the shortcomings:
  • Change the focuser to a Crayford style (lookig for a used one to adapt) as the helical + extension (plug-in not sliding) is a pain
  • Store the scope dust protected in a location closer to ambient temperatur to get quicker cool down
Long term I will try to direct compare to a 120 ED, one member has offered via PM.
Depending on what this comparison shows I will either be happy with my Mak or hunt for a 120mm ED or try to have a look through a premium 120 APO.

Cheers,

Peter
Probably a good decision to take your time. Please share your thoughts when you compare the two scopes.
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  #36  
Old 12-07-2013, 06:53 PM
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Why would anyone bother spending almost 5k on a TSA-120 if a SW BD120 for approx. 2k was just as good
Maybe not quite "just as good", but good enough for most people?
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  #37  
Old 12-07-2013, 07:24 PM
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Unfortunately there are many theoretical opinions or opinions based on speculation. Also different people have different preferences and eyesight. The only sure way is to tell by looking through the scopes and if possible do a side-by-side comparison.

If you are ever near Canberra you are welcome to test drive my TSA-120.

Cheers
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  #38  
Old 12-07-2013, 08:52 PM
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Hi prof.I use mostly a 10"SCT, 80mm acro and 5" mak at the moment.lovely views of saturn one night with a 5mm nagler and parks in the mak.Sct better than all when its ready.But Ive spent my doe on nice, House, merc,jag etc.So the tak 150 is off the agenda. Id rather finish up with a nice mak Prob should have got the mewlon, bd, or intes instead of going car mad again
Cheers prof and all. ps dont do this on a mobile pulled over somewhere.Its very difficult to say the least.Engine turned off! . Of course!!!

Last edited by bigjoe; 12-07-2013 at 09:35 PM. Reason: appaullng grammar etc
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  #39  
Old 12-07-2013, 10:59 PM
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Hi Joe

Good to hear (except for the car issue) and it sounds like you have spent your astronomy money very wisely as the most useful piece of astronomy equipment is your own backyard to look up at night.

Take care my friend
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  #40  
Old 12-07-2013, 11:04 PM
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A Fiat will get you to work as well as a Ferrari would but I can still understand why someone would want a Ferrari.

If driving simply consisted of going to work and nothing else then there would be no point.

However, if you needed to get somewhere really fast (for example) and ensuring all four wheels stay on the ground as you take a hard turn I know which car would be the better and thus, in reality, there are big differences.
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