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4" refractor; 127 Mak; or stay with TV 85?

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#1 Astroduty#57

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Posted 10 January 2020 - 01:58 PM

 I have a televue ranger on a telepod mount which I have owned forever & a televue 85 which I purchased last year.  The tv-85 is on a DV-1 mount from desert sky astro. Both are great!

For visual, would I notice any significant difference on planets with a 4" refractor or 127 Orion Mak  from my Televue 85?

Thanks!


Edited by Astroduty#57, 10 January 2020 - 01:59 PM.


#2 Jeffmar

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Posted 10 January 2020 - 02:18 PM

I am not sure if this comparison is similar enough to your situation. I own an Orion 80mm ED doublet that has good color correction and I used to own an Orion 127mm mak. I noticed a pretty significant difference between my 80mm and 127mm mak viewing planets. The views through the mak noticeable  better detail and a little better contrast. I couldn’t say for sure what difference a 4 inch refractor would make. I only know what I have seen with my scopes. My 80mm scope is much better for wide angle views than my mak was. My mak was definitely better for planets and DSO’s at higher magnification.


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#3 Astroduty#57

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Posted 10 January 2020 - 02:30 PM

Thanks.

Why did you replace the Mak, if I may ask,?



#4 Nippon

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Posted 10 January 2020 - 02:34 PM

I had a TV 85 for about ten years and then bought a Vixen ED 103s I found the jump to 4" very noticeable. Both are ED doublets. The Vixen FPL53  and the TV 85 most likely FPL53. I have not looked through a 127 mak but I would be surprised if it could keep up with a good 4"ED.


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#5 Eric H

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Posted 10 January 2020 - 02:37 PM

I would go with the Mak for is longer focal length if you are just adding a scope to the arsenal. If replacing...go with a 4" frac. They are very versatile.


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#6 vtornado

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Posted 10 January 2020 - 02:37 PM

I did a shoot out between a 100mm f/9 synta ED doublet and 127mm mak.

They were about the same on planetary/lunar detail

 

The 100/9 can go wider because of the shorter FL and ability to handle 2 inch eyepieces, so in general

it is a more versatile scope.

 

I have just purchased a 80mm synta ED, but now the planets are gone, and I can't really

compare 100 vs 80 for planetary detail.

 

You would be losing whatever premium optics gives you, and I have never viewed through one

to no how much I would be giving up.

 

Besides text book resolution calculations, there is also exit pupil.  I find I stop seeing more detail

at about EP=.7mm.  The 100 then gets you 150x, where the 85 is 120x

 

According to DessertSky the DV1 is recommended for a 100 f/7.  The 100 f/9 might be pushing it.

 

========

 

My 150mm f8 dob is better than either the 127mak or 100ED, if you want to go there.

It is not a giant leap, just a step better.


Edited by vtornado, 10 January 2020 - 02:42 PM.

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#7 Astroduty#57

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Posted 10 January 2020 - 02:56 PM

Thanks!

I will keep reviewing all of the suggestions. Nevertheless, I will not stop using the Televue scopes but might wish to have something a little larger for planets.



#8 Eddgie

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Posted 10 January 2020 - 03:54 PM

 I have a televue ranger on a telepod mount which I have owned forever & a televue 85 which I purchased last year.  The tv-85 is on a DV-1 mount from desert sky astro. Both are great!

For visual, would I notice any significant difference on planets with a 4" refractor or 127 Orion Mak  from my Televue 85?

Thanks!

If you define "significant"  as suddenly seeing a wealth of festoons on Jupiter or structure in then bands, or resolving the hex on Saturn, seeing a lot of detail on Mars,  I would say "no."   You might see a bit more, but just a bit.  Now as these things go, a bit is a bit, but to me, to see a really significant difference, you would need to be looking at maybe a 120ED or a 5" Apo, or maybe a premium MCT.  Any of these will provide a significant difference.

 

Better still would be a cheap 8" f/6 with mirrors refinished by a pro.  Now this is a substantial difference with all of the things I mentioned in my first sentence becoming very exiting to see. 

 

Now you can try the luck of the draw with mass produced MCTs.  Maybe you will get a really excellent one, but if it has to be small, an Intes or TEC 6" would both be potent small mount planetary scopes. 

 

I don't think you are going to get a wow by going to a 100mm refractor or 5" MCT.  Yeah, a bit better.  Worth the money?  eh.  If planetary is important, there are better ways to spend that money.  


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#9 RadioAstronomer

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Posted 10 January 2020 - 03:55 PM

I find the planetary views of a good 4" refractor and a 127 Mak equivalent. However I prefer the 4" refractor for its wide field capability, its faster acclimatation and for the lack of collimation issues.

And yes, the jump from a TV-85 to a good 4" refractor is noticeable.


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#10 cst4

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Posted 10 January 2020 - 04:00 PM

Since you do not plan on replacing your TV scopes, I'd recommend the 127mm mak to add a little variety to the mix.  The DV1 would probably handle the short 5" mak better than a longer 4" apo.  Plus better exit pupils at high mag with the longer focal length.



#11 mikeDnight

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Posted 10 January 2020 - 05:16 PM

The TV85 is a very nice scope, but you will definitely notice a significant jump in performance if you move to a 4" ED/apo refractor. If you decided on something in the F7 region you'll have great wide/rich field views, while at the same time its high power lunar and planetary, as well as deep sky and double star prowess will definitely impress. A good 4" refractor can be a lifetime scope for many. If you're purely a visual observer, a good ED or fluorite doublet is all you'd need, as the CA will be virtually none existent. 

And as you can see from the attached pic, it can be pleasingly simple.

 

2019-01-28 19.57.27.jpg


Edited by mikeDnight, 10 January 2020 - 05:21 PM.

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#12 SeattleScott

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Posted 10 January 2020 - 05:17 PM

If you go from a TV85 to a 4” it better be a good 4”. Vixen or Tak comes to mind.

Scott
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#13 YAOG

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Posted 10 January 2020 - 05:37 PM

If you go from a TV85 to a 4” it better be a good 4”. Vixen or Tak comes to mind.

Scott

I agree. But even my Celestron XLT 102mm ED and Vixen ED100Sf were better than my TV85 which is why I sold the TV85. Of course they had the advantages of longer focal ratio but even having the same 100mm objective and f/9 focal ratio couldn't save them from the advantages of Fluorite in the Takahashi FC100DL so out they went also. 


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#14 KerryR

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Posted 10 January 2020 - 05:39 PM

I have a Megrez 90 (close enough to  85 for comparison), an Orion ED100, and a Synta 127 Mak.

 

When I grab the 90, I don't find myself missing, much, the slightly larger aperture of the others. As Ed mentions above, if you're looking for something more than a somewhat subtle performance increase, you'd probably be best served by a larger step in aperture (and probably mounting, too!).



 



#15 Jeffmar

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Posted 11 January 2020 - 11:46 PM

Thanks.

Why did you replace the Mak, if I may ask,?

I used the money from the mak to help buy a Celestron C8 edge scope. I wanted something that had  a bigger aperture but was still fairly light.  The only down side for the C8 is it needed a bigger mount than the 127 mak, but I already had one for a bigger scope, so for me it wasn’t an issue. 

 

I liked the optics of the 127mm mak a lot but the relative focal length made the field of view kind of narrow.


Edited by Jeffmar, 11 January 2020 - 11:48 PM.


#16 25585

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Posted 12 January 2020 - 04:29 AM

120mm refractor is the next step. Big difference from your TV 85 & better than a 125mm Mak or SCT


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#17 Jon Isaacs

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Posted 12 January 2020 - 04:48 AM

My two cents:

 

The 127mm Orion Starmax I had never impressed me.  The views were soft compared to a refractor and lacked the crispness I expect.  It might have showed the same detail as a 4 inch, I never made that comparison, but I was not happy with the views.

 

For someone coming from a TV-85, the Mak is likely to be disappointing.  

 

Jon


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#18 KerryR

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Posted 12 January 2020 - 11:05 AM

My two cents:

 

The 127mm Orion Starmax I had never impressed me.  The views were soft compared to a refractor and lacked the crispness I expect.  It might have showed the same detail as a 4 inch, I never made that comparison, but I was not happy with the views.

 

For someone coming from a TV-85, the Mak is likely to be disappointing.  

 

Jon

I'd have to say I haven't been terribly impressed with my Synta 127 Mak, either. It's fun enough for the price I paid (used), but it just never seems to be the scope I feel compelled to grab, for the same reasons, above. I'm doubtful, too, that a 127mm Synta Mak would be a solid enough step up from a TV-85.

 

If a solid step up in detail and resolution for planets in the primary concern, I'd feel inclined to suggest a much larger, probably mirrored, scope. But that has it's own set of limitations, such as mounting and cool-down. 

 

Personally, I really like 60-100mm refractors, and I just accept their limitations. In this regard a TV-85 (or, in my case, the Megrez 90) is tough to beat...


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#19 sunnyday

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Posted 12 January 2020 - 11:21 AM

I do not know if I will be able to explain my experience so that you can understand.
I had a 127 mm mak and compare to the view in a 4 inch lunt ed, I found the image more brilliant and more crips, in terms of detail, I prefer the 4 inch. I hope it makes sense - google translate is my friend.


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#20 Jon Isaacs

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Posted 12 January 2020 - 11:38 AM

I do not know if I will be able to explain my experience so that you can understand.
I had a 127 mm mak and compare to the view in a 4 inch lunt ed, I found the image more brilliant and more crips, in terms of detail, I prefer the 4 inch. I hope it makes sense - google translate is my friend.

 

The Maks are actually about 120mm true aperture and actually have a 40% central obstruction. Orion is devious in the regard, the quote the "secondary mirror obstruction". Sounds good but the secondary baffle is the actual obstruction and it's about considerably larger.

 

If one buys a high quality 5 inch Mak, it could be a different story. 

 

Jon


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#21 KerryR

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Posted 12 January 2020 - 12:03 PM

The Maks are actually about 120mm true aperture and actually have a 40% central obstruction. Orion is devious in the regard, the quote the "secondary mirror obstruction". Sounds good but the secondary baffle is the actual obstruction and it's about considerably larger.

 

If one buys a high quality 5 inch Mak, it could be a different story. 

 

Jon

Flashlight testing mine shows  117-118mm (width of the shadow gradient ~1mm). Close enough to 120, of course, but still irritatingly below 127mm. This is the only small scope in my collection whose test falls below the stated aperture (I've only tested my 6" and smaller scopes). There's been significant debate about the efficacy of the flashlight test, particularly with complex systems like Maks, but I find the arguments in support of "close enough" compelling. This isn't a deal breaker, really, but it might provide some additional support to the notion that the OP would be better served by something other than a Synta 127 Mak as a meaningful upgrade/compliment from/to the TV 85.


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#22 Jon Isaacs

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Posted 12 January 2020 - 12:14 PM

This isn't a deal breaker, really, but it might provide some additional support to the notion that the OP would be better served by something other than a Synta 127 Mak as a meaningful upgrade/compliment from/to the TV 85.

 

 

I think it's important not to take my comments and others comments as bashing the Orion 127 mm Maks. These scopes are under $400 and offer performance in a compact size at a price.

 

But expectations are based on experience so moving from a TV-85 to a 127 Orion Mak is likely to be disappointing. 

 

Jon


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#23 astro42

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Posted 12 January 2020 - 12:40 PM

My question is where do you find the higher quality MAK everyone seems to mention?

One that is available and not trying to find a used one.


Edited by astro42, 12 January 2020 - 12:42 PM.


#24 eros312

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Posted 12 January 2020 - 12:54 PM

My question is where do you find the higher quality MAK everyone seems to mention?

One that is available and not trying to find a used one.

https://explorescien...fl-mc1271900eq3 Not high quality, but it works at full aperture and is available new. 



#25 astro42

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Posted 12 January 2020 - 01:50 PM

So what's the difference with the Explorer Scientific mak and a Skywatcher/ Orion maks?


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