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Best planetary performe Frac or Mak ?

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#1 telco507

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Posted 17 December 2018 - 02:06 PM

Hello friends,

 

 

For all of you experts, which telescope would be a better suited option for visual planetary/lunar astronomy.

 

Skywatcher 4 inch ED refractor or Meade/Skywatcher  6 inch F15 Mak?.

 

 

Best regards

 

GDL(507)



#2 dr.who

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Posted 17 December 2018 - 02:09 PM

A well figured good quality mirror set with proper cooling and collimation, the Mak will provide the better planetary views.
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#3 sg6

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Posted 17 December 2018 - 02:26 PM

To differ (but I enjoy it) - get the 4" ED.

Reason - somehow you have a scope dropped under the Christmas tree by Santa. And out you go to look at Jupiter, except it isn't visible, so you turn to try Saturn, and that isn't there either. That red thing is Mars and you see a small red disk, but that is all you will see, no detail. Too far away at present and I think is a cresent only.

 

Jupiter is good at only 60x, Saturn is good at 120x. A 100mm ED should produce 150x and 160x with very good views. So both are capable. Mars needs more then either scope is really capable of.

 

The ED is good for other objects and in my thinking a better all round scope. Hence the ED over the Mak.

 

The Mak would be better for planetary imaging, if that is a specific requirement.



#4 Redbetter

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Posted 17 December 2018 - 02:26 PM

In Panama one would expect a Mak to have favorable thermal performance compared to a Mak in a temperate climate (often cold at night).  The one negative that might arise would be increased dewing tendency since I imagine the typical humidity level is high.  That would be a question to pose to Mak users in similar climates.

 

Assuming good figure for the 6" Mak, I would expect it to somewhat outperform the 4" refractor for planetary/lunar detail.  However, some of the wider scale contrast will probably be better in the refractor.  In comparing a good 127 Mak to a 110 ED refractor (f/7 with the older somewhat lesser performing FPL-51) the 110 shows slightly more detail and has better contrast when searching for the fainter moons of Saturn.  These two particular scopes have nearly the same theoretical light throughput, and this 110 is probably closer to a 100 ED w/ FPL-53 in effective performance.  Another inch of aperture in the Mak should easily shift the detail in its favor.  (Note:  I had to collimate both of them to get the best images...the Mak and the refractor.  Collimation isn't just for Dobs and SCT's.)  



#5 Adun

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Posted 17 December 2018 - 05:00 PM

For all of you experts, which telescope would be a better suited option for visual planetary/lunar astronomy.

 

Skywatcher 4 inch ED refractor or Meade/Skywatcher  6 inch F15 Mak?.

 

Hi, greetings from neighboring Colombia!

 

I'm not really an expert, but here are my thoughts:

 

1) In our latitude, we are blessed to have the planets and the moon very high in the sky, with the ecliptic crossing within 20º of zenith. So for lunar/planetary you're much more likely to have a vertical (or almost vertical) telescope, and a short tube Mak will be more ergonomic than a long F9 refractor in this regard. Try to visualize how the eyepiece position varies more, and gets very low when aimed at zenith.

 

2) In our countries, importing a heavy mount can be expensive. Because of being shorter, a Mak or SCT has less momentum, and can be mounted on a smaller (less expensive, less heavy) mount than an ED refractor. I can mount my 6" SCT on my Exos Nano mount and it works well, while a Sky-Watcher ProED 100mm f/9 would not cut it on it. Fewer Equatorial mounts work at our latitudes (the counterweight bar can hit the legs, etc). GoTo mounts are more expensive here. The Mak's mount friendliness is a plus over here.

 

3) For many, "ED doublet" does not truly mean apochromatic. It takes a triplet lens to fully correct for chromatic aberrations, and it takes a quad (triplet + field flattener) to get a properly flat field. The ED might seem crisp visually, but the moment you start taking pictures of planets, and your camera reveals the ED's hidden CA, you'll wish you had chosen a Mak. 

 

¿Why take pictures? Because with a planetary camera you can capture more detail than you can see with the bare eye, specially from Panama/Colombia where planets can get so close to zenith. I could see more Martian features on this image, than I could see through an eyepiece on the same scope same night I captured it:

 

Mars image with C90 and IMX224

(this is with a 90mm Mak and a $165 RT224 camera, around the recent opposition)

 

4) Resolution comes from aperture. To see "festoons" in Jupiter, or the shadow of it's moons during transits, or finer detail in our moon, you want resolution and that comes with aperture. I'd say it takes a refractor larger than 4" to match the resolution of a 6" Mak, even after accounting for the detrimental effect of the central obstruction.


Edited by Adun, 17 December 2018 - 05:04 PM.

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#6 Diego

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Posted 17 December 2018 - 06:30 PM

I have all types of telescopes and to be honest, I was very very surprised at the planetary image my 127 Celestron mak threw at me. It would probably be a close call compared to 4" refractor. However I chose the mak over the refractor because you get decent aperture in a compact OTA, cheap compared to ED refractors, no CA, less demanding on the mount, easy to pick up and move out doors, VERY comfortable viewing position, good with cheap eyepieces.

Cons may be small FOV (doesn't bother me) and long fl makes it hard to get low powers.

However I bought it for the specific purpose of planetary viewing since I live in the city, so for this purpose it fit perfectly my needs.

I do plan to take it deep sky observing one day as the compact size just begs it.
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#7 Tony Flanders

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Posted 17 December 2018 - 07:41 PM

To differ (but I enjoy it) - get the 4" ED.

I prefer a 4-inch APO to a 6-inch Mak-Cas as an all-around telescope. But for the specific purpose of viewing the Moon and planets, the extra resolution of the Mak is so big that it outweighs the APO's numerous other advantages.


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#8 Asbytec

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Posted 17 December 2018 - 08:58 PM

 

Skywatcher 4 inch ED refractor or Meade/Skywatcher  6 inch F15 Mak?.

 

In my view, it's a mixed bag. Generally and assuming descent optics in both, a 6" MCT properly prepped for observing (cooled and collimated) will have the resolution of a 6" ED, roughly the throughput of a 5" ED, and theoretically the contrast transfer (small planetary detail) of a 4" ED, give or take a few tenths of ED aperture. 


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#9 Conaxian

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Posted 17 December 2018 - 09:22 PM

The eyepieces used in the mak to get, say, 180X will be longer F/L than the eyepieces (sans barlows) to reach the same magnification in the shorter refractor. The longer eyepieces can deliver longer eye relief, which makes for more enjoyment at the eyepiece.

That said, I would really like to have a 100 to 127mm ED refractor because they have no obstruction, less touchy, delicate mirrors and produce sharp, high contrast images.  They also last forever with a little care.

The short tubed mak would be more comfortable to use, easier to mount well and provide greater resolution with its larger aperture.

You can't go wrong, really. Either type would be great. The mak would be lower priced, and cost is always a factor.



#10 Jon Isaacs

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Posted 17 December 2018 - 09:24 PM

In my view, it's a mixed bag. Generally and assuming descent optics in both, a 6" MCT properly prepped for observing (cooled and collimated) will have the resolution of a 6" ED, roughly the throughput of a 5" ED, and theoretically the contrast transfer (small planetary detail) of a 4" ED, give or take a few tenths of ED aperture. 

 

In general I lean towards refractors when observing with smaller scopes like these.  When everything is right, the MAK might be the better performer by a slight bit but the refractor will be right nearly 100% of the time, the MAK, who knows how often.

 

Jon



#11 Eddgie

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Posted 17 December 2018 - 09:58 PM

It is not just the resolution of the instrument that is at play, it is also the added brightness.

 

First thing to know is that the majority of the resolution in the human eye is provided by the cones in the fovea.   

 

And this is what you need to know about the cones.  Unlike the rods, which are clustered together with several sharing a neuron, the cones each get their on neuron.  Because a given number of photons have more chance of hitting one of the ganged up rods, we get excellent dark adaptation, but the rods only allow about 3 arc minutes of resolution.  The Cones will fire less for a given number of photons, but the cones allow resolution of about 1.1 arc minute.

 

But this is even more important.   The rods are sensitive to green, but the cones see the other colors.

 

So, the cones are the key to getting the best planetary resolution, and the key to firing more cones is to get a brighter image, and the key to getting a brighter image is to use a larger aperture. 

 

When powers get high (say 200x) the 4" will have such a small exit pupil that the view becomes very dim, and if the observer has floaters, these can become far more of a problem.   (This dimming is really what imposes the limit to how much you can magnify and image).

 

The larger aperture you use, the more the added brightness stimulates the cones, and your resolution and color perceptin both go up. 

 

For the average observer, colors will be very muted at 4" and the higher the power, the more muted the colors become (fewer photons hitting the cones because the energy is spread out more).   Even at 6", colors will be very subdued, but typically at 6", the ability to start to perceive some shading difference in the major belts of Jupiter and Saturn.  At 8"to 10", colors start to saturate and you can start separating multiple bands on Saturn, and Jupiter starts to show pale yellows and blues.    At 12", Saturn, Jupiter, and Mars show considerable shading and the blue color of Neptune is quite pronounced.

 

So, aperture is your friend because the added luminance that aperture provides allows you to use higher powers to get angular resolution and heightens your ability to perceive color (which in itself reveals detail that are not seen using much smaller apertures, like showing you that a "green" band on Saturn is actually made up of a narrow green and narrow pink band.  Saturn really is far more colorful that people using very small apertures can perceive it.

 

My recommdation then would be that when planetary is a high priority, always use the largest and highest quality optics that one can obtain.    

 

Sadly, the quality of the mass market 150mm MCTs varies, and while I don't trust that all will have excellent optics, most will be reasonable and 150mm of aperture will provide a lot of luminance gain, and I would trade some amount of quality for some amount of luminance. 

 

If the choice was for something like an Intes Micro MN66 or one of their exceptional 6" MCTs, or the superlative TEC 6" MCT, it would be a total stomp, but with the mass produced MCTs, I don't think the difference will be nearly as much , but I think (having owned all three of these kinds of scopes) that the 6" mass market MCT brings enough extra aperture to the came to offset the limits of the design.  

 

For planetary though, I recommend always recommend a larger scope because the difference in luminance between a 6" scope and a 10" scope is enormous, and a good 10" reflector is a very difficult telescope to beat on planets on most nights for most observers.   I have observed planets for 35 years, and no small scope I have used has come close to providing the high contrast views that one can get with a 10" reflector with a high quality mirror. 

 

Of these two though, I would go with the MCT. 


Edited by Eddgie, 17 December 2018 - 09:59 PM.

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#12 Eddgie

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Posted 17 December 2018 - 10:04 PM

For those interested in learning more about the enormous role that the human eye plays in high resolution observing (which is almost always glossed over on the refractor forum when people are comparing this scope to that scope) and the role of luminance, I recommend this page with special attention to figure 250:

 

https://telescope-op...al_response.htm

 

And this page, which explains the eye response to light intensity:

 

https://telescope-op...ty_response.htm

 

As it turns out, it is not just about the design of the telescope, it is to a very great extent about the design of the human eye.


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#13 telco507

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Posted 17 December 2018 - 10:35 PM

Thanks Adun and everybody for their comments.

 

Adun, now that you mentioned, which entry level GEM do you recommedn for very low latitudes?.

 

Best regards,

 

GDL(507)



#14 Asbytec

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Posted 18 December 2018 - 01:43 AM

In general I lean towards refractors when observing with smaller scopes like these. When everything is right, the MAK might be the better performer by a slight bit but the refractor will be right nearly 100% of the time, the MAK, who knows how often.

Jon

Agreed with smaller nearly same apertures. In this case, though, the MCT is a bit larger. It has a few inherent advantages over a 4", but not entirely. A long focal length might be one if them. Rote resolution is, but maybe or maybe not small planetary contrast.

Edited by Asbytec, 18 December 2018 - 01:44 AM.

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#15 Magnetic Field

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Posted 18 December 2018 - 04:45 AM

I have all types of telescopes and to be honest, I was very very surprised at the planetary image my 127 Celestron mak threw at me. It would probably be a close call compared to 4" refractor.

 

Has been known for the last 40 years.

 

The refractor forum is completely impervious to that fact though.



#16 Adun

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Posted 18 December 2018 - 07:20 AM

Adun, now that you mentioned, which entry level GEM do you recommedn for very low latitudes?.

 
I make do with an Exos Nano, which still has enough clearance between counterweight and legs at 3°N, but it is kind of borderline. One problem with that mount is that the standalone version (the one sold for $99) comes with insufficient counterweights, I had to buy an extra counterweight. The version of the Nano that comes as part of the "FirstLight AR102" has a better counterweight.
 
With the included counterweight it can only carry my 90mm Mak and my 114mm reflector, but with the extra 6lb counterweight I got, it can carry my 6" SCT very well (I was surprised by how well). The legs are also a weak point, I use it with the legs collapsed (not extended) to reduce vibrations. Since I installed an RA motor, it became my EAA / video astronomy mount for imaging with my 114mm reflector.

 

I'm not very fond of GEM mounts though. It's probably the weight (I have a bad back). My favorite mount for observing planets is the GSO Skyview Deluxe, which is a manual alt-az. With my 6" SCT it makes a lightweight "grab and go" setup.

 



#17 oldtimer

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Posted 20 December 2018 - 09:21 AM

My 6" Konus Mak is a great planetary scope and even doubles as a very good DSO scope with my 40m 68 degree 2" eyepiece giving 45X with a 1.5 degree FOV.



#18 Jon Isaacs

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Posted 20 December 2018 - 09:47 AM

Has been known for the last 40 years.

 

The refractor forum is completely impervious to that fact though.

 

A couple of years ago I spent some time comparing my 120mm Orion Eon to my 127 mm Orion Starmax.  The difference was amazing.  one night I set the Mak out for 2 hours to make sure it was cooled, it just was not as sharp or crisp as the refractor.  I even added a 40% CO to the refractor to simulate the effect of the central obstruction. Still a big difference.   

 

Optical quality is a big player.  If one is talking TEC and Astro-Physics Maks it's quite a different story than Skywatcher Maks... 

 

Jon


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#19 Asbytec

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Posted 20 December 2018 - 10:07 AM

"Still a big difference."

Wonder why. I'm sure the Eon was a very nice scope. As you know, I've had a blast with my MCT. I'd love to see the difference.

I've always been curious about what a similar APO can show that I cannot see in the Mak. A bit sharper and more soft contrast detail, no doubt, at similar aperture. But how much?

The mak is obstructed, after all, operating near, at, or just below the diffraction limit while the Eon is operating at its high unobstructed Strehl. Surely a difference between 0.97 and 0.79 can be observed and makes a difference.

I have to question the quality of the 127 Mak if an obstructed 120 Eon made that much difference. I cannot think of any other reason why it should fall so short.

I believe my own MCT is smooth and well corrected. I've seen some amazing things in it like craterlets less than a mile in diameter, split some tight stars, and observed Mars nicely at over 400x.
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#20 Magnetic Field

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Posted 20 December 2018 - 12:07 PM

A couple of years ago I spent some time comparing my 120mm Orion Eon to my 127 mm Orion Starmax.  The difference was amazing.  one night I set the Mak out for 2 hours to make sure it was cooled, it just was not as sharp or crisp as the refractor.  I even added a 40% CO to the refractor to simulate the effect of the central obstruction. Still a big difference.   

 

Optical quality is a big player.  If one is talking TEC and Astro-Physics Maks it's quite a different story than Skywatcher Maks... 

 

Jon

An ED semi-apo of similar aperture will always be the safer bet.

 

According to google: The 120mm Orion Eon OTA costs $1500. The 127mm Orion Starmax costs $500 (this already includes an equatorial mount).

 

 

One has to assume that the optical quality of the Orion Maksutov will be hit and miss given the price.



#21 Magnetic Field

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Posted 20 December 2018 - 12:18 PM

"Still a big difference."

Wonder why. I'm sure the Eon was a very nice scope. As you know, I've had a blast with my MCT. I'd love to see the difference.

I've always been curious about what a similar APO can show that I cannot see in the Mak. A bit sharper and more soft contrast detail, no doubt, at similar aperture. But how much?

The mak is obstructed, after all, operating near, at, or just below the diffraction limit while the Eon is operating at its high unobstructed Strehl. Surely a difference between 0.97 and 0.79 can be observed and makes a difference.

I have to question the quality of the 127 Mak if an obstructed 120 Eon made that much difference. I cannot think of any other reason why it should fall so short.

I believe my own MCT is smooth and well corrected. I've seen some amazing things in it like craterlets less than a mile in diameter, split some tight stars, and observed Mars nicely at over 400x.

It could well mean the Orion Maksutov was a lemon.

 

I do not think obstruction is the problem. Obstruction is overrated. Even in an ED semi-apo the colour error is large and will reduce contrast (refractor people are also impervious to that fact).

 

I think there is a gap between the junk that comes out of China and the offerings of good quality affordable Maks. By affordable I do not mean Questar or Astrophysics.

 

Does anyone know why Intes or the Russians stopped producing affordable high quality Maks?*

 

*When I was a PhD student I sold my Intes 6" Mak to a friend. He still has it.


Edited by Magnetic Field, 20 December 2018 - 12:41 PM.


#22 Jon Isaacs

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Posted 20 December 2018 - 12:29 PM

An ED semi-apo of similar aperture will always be the safer bet.

 

According to google: The 120mm Orion Eon OTA costs $1500. The 127mm Orion Starmax costs $500 (this already includes an equatorial mount).

 

 

One has to assume that the optical quality of the Orion Maksutov will be hit and miss given the price.

 

I am quite sure that's a good part of it.  In my experience,  ED/apo refractors are quite consistently of high quality.  The difference between an ED-100 and a 4 inch premium scope is relatively small and thermal stability is rarely an issue with either. 

 

Jon


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#23 csa/montana

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Posted 20 December 2018 - 01:13 PM

Folks, this thread is going to be moved to Equipment for better fit; as we are trying to keep this forum free of equipment posts.

 

Thanks everyone!


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#24 Asbytec

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Posted 20 December 2018 - 07:16 PM

I do not think obstruction is the problem. Obstruction is overrated. Even in an ED semi-apo the colour error is large and will reduce contrast (refractor people are also impervious to that fact).

 

I think there is a gap between the junk that comes out of China and the offerings of good quality affordable Maks. By affordable I do not mean Questar or Astrophysics.

 

Does anyone know why Intes or the Russians stopped producing affordable high quality Maks?*

 

I might agree the obstruction is overrated, but it does an effect. A perfect 33% obstructed scope can just hit the "diffraction limit" with 0.8 in the central disc, and a mid 90's Strehl can perform equally with a smaller obstruction. I assert that is a good image. A good refractor will likely be somewhat better. It may be hampered by chromatic aberration in about the same way the obstructed is hampered by diffraction artifacts. With CA, you get a colored halo near the limb of extended objects, with an appreciable obstruction you get a diffraction artifact near the moon. I've seen it when seeing is good. A lot depends on how much it bothers you, but those same effects are affecting contrast. In the end, it's possible (but not required) for both scopes to function more closely than not provided that are of good and comparable quality. Then there is the "pleasing" aspect. 

 

Jon seems to show the obstruction is likely not the problem when he obstructed the Eon for comparison and found it was better. Yes, residual color can also the Strehl over a range of wavelengths, but a refractor still operates at it's unobstructed Strehl whatever it is. And they tend to handle thermal issues a little better. To my mind, that leaves the quality of the 127 sample tested in question or suffering from thermal gremlins. I'd expect Jon would know the difference and would have noted any thermal issues. 

 

I guess Intes is a good quality affordable Mak, consistently so. China does seem to have some hit and miss aspect, but it's been my experience in the last few years they produce some good quality. Maybe not consistently so. But, each scope I've owned over the past decade has been at least good. Intes used to claim 1/6 PVW in their standard models. I dare say my own China Mak (Synta) is about that good, though it is certainly not a premium Mak. But, it is affordable. Cost reduction, thus lower prices, are a business model. Just because Chinese get paid less in terms of dollars does not mean the scope is "cheap" relative to their wages paid in their currency. It just means the company is saving on cost and competing with rival companies through pricing strategy and making a profit. This may be the same reason Intes was (or is) more affordable, too, one of the the reasons German Maks are not as affordable along with their penchant for quality. The difference is Intes and other premium Maks offer a guarantee and often a test report. China does not. It may be that Intes quit selling because they could not maintain an affordable price.

 

I tend to agree with Jon that in the smaller aperture range, a refractor is preferred. An obstructed 4" CAT falls into the 3" range in terms of throughput and planetary contrast. Refractors are also preferred in the 6" to 8" range, too, but become less affordable. So, in the 6" and larger range we might tend toward a MCT or SCT, and maybe Dobs as aperture extends beyond 10" or so. Not always, though, nothing is absolute. I think I might prefer a 4" refractor to a 4" MCT or SCT, but prefer a 6" Mak over a 4" refractor.  And a 6" refractor over a 6" MCT, maybe, and and a 12" Dob over a 6" APO, and so on. The ergonomics aspect plays a role, too. And as costs spiral upward we compromise a little more. 

 

In my experience I really like bang for the buck. At less than $1000 over 7 years, including a solid GEM, I have to say my MCT is my most used scope and maybe the best bang for the buck I've had the pleasure of knowing. Less than a dollar a day. It got so much use over the years, more than any other scope I've owned. For several reasons, two of which are being retired with time to observe and the outstanding tropical seeing. And the images have been nice. Maybe not 6" APO nice, but at least 4" APO nice. My most recent 8" Dob is shaping up to be another bang for the buck scope as I work out collimation, thermal, and tracking issues. It star tests very nicely for only $300 plus $200 shipping and another bit for a RACI finder and flocking paper. (OUCH!) LOL  But, I had a great view of Rimea Aristarchus the other night (lunar forum.) Sweet! 

 

So, what's the best planetary scope? The one you use, hopefully a thermally stable good sample operating in good seeing. Maybe some aperture and ergonomic considerations, too, that is affordable. If you cannot afford it, you cannot use it. 


Edited by Asbytec, 20 December 2018 - 07:30 PM.

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#25 Redbetter

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Posted 21 December 2018 - 05:09 AM

FWIW, I would expect a 120 Eon to outperform a 127 Mak to a noticeable degree even if both had near perfect figure and they were both thermally stable. 

  • If I am not mistaken, my assumption is that this would have been an 127 Orion Mak of 118 to 120 mm effective aperture since the primary was not oversized for the meniscus.  So they are essentially the same resolution/aperture.  One with a large obstruction, the other without. 
  • The Mak has two mirrors in the system to introduce some scatter and reduce overall transmission.  The system transmission impact along with the smaller effective aperture would put it closer to 102 to 105mm in terms of image brightness. 
  • The mirror scatter impact is a characteristic shared with Newts.  A few percent of extra illumination where it is not intended will rob some contrast, even with the best figured and polished mirrors. 

The above only partially explain the difference with an obstruction on the refractor, but still represent a significant trifecta even with the obstruction:  same effective resolution aperture, dimmer overall image for the Mak (mirror transmission vs. lenses), increased scatter for the Mak.   

 

I don't disagree with Jon or others about the likely differences in optical quality of the refractor vs. the Mak.  For the ED doublets and APO triplets very good figure and collimation are the norm.  The average Mak might be good, but is unlikely to be as good.   It could be an average sample or a lemon. 

 

I suspect that the visual comparisons I have made of a 110 ED (FPL-51 f/7 doublet) and another 127 Mak f/15 (w/ ~40% obstruction and near full effective aperture) might be somewhat closer to equivalence for this type of comparison.  Both were collimated by me as best I could get them, and well equilibrated multiple nights during the mild night time conditions viewing Jupiter and Saturn.  The 110 definitely performed better, but not by a large margin.  The 110ED is not visually apochromatic, but is well baffled.  It shows some blue/violet on bright white objects and this steals some contrast.   The calculated effective overall light throughput of both (in terms of limiting magnitude) is nearly identical after accounting for optical surfaces and obstruction. 

  • Both have useful planetary magnification to very similar values, about 220x in the ED, about 211x in the Mak.  Past that both seem to be providing empty magnification with regard to detail.
  • The most noticeable detail difference was in the number and crispness of festoons visible on Jupiter.  The 110 showed a solid increment more.  E.g. 2 or 3 vs. 3 or 4 with a discernible difference in crispness.  
  • Both were able to reveal the largest of the white ovals in the STB.  The equivalence actually surprised me, since both were marginal but certain detections confirmed with larger scopes and neither revealed smaller additional ones visible in larger scopes.  Contrast for these is perhaps higher than for the festoons, so resolution is more a factor than contrast for detecting the ovals.
  • For Saturn I was mostly comparing the background brightness of the field (scatter and obstruction diffraction impact).  This was done by trying to detect various moons in suburbia.  The 110 ED produced a darker background and this translated into detecting incrementally more moons when conditions were marginal.  The dimmer moons were more difficult to detect in the Mak.   

I would expect a 120 Eon w/ FPL-53 to incrementally outperform the 110ED by about the same margin.  But that is just an extrapolation.  For equal quality Mak's the ES 127 would likely outperform a smaller effective aperture Orion 127 by a somewhat smaller margin.   The expected ranking would be:  120 Eon > 110ED > ES127 > Orion 127.    And I would expect a 150 Mak operating at full effective aperture to top them all. 

 

As for cost, the ES 127 Mak was $300 delivered, new, along with an included mount that is really only usable with something like a very short AT60ED refractor (the little Chickenhawk most often "nests" on this mount anymore.)   

 

When it comes to portability and suitable mount, it is no contest between the  127 Mak and the 110ED.  The 127 rides happily on the Twilight I (displacing the 80ED which was also well mounted on it but didn't provide as much detail).  The 110ED requires a bulkier/heavier CG4 for adequate mounting.  So the 127 comes out to play more often in town.  On the other hand the 127 Mak hasn't made trips to dark sky sites that I recall, because it lacks the wider field capability that makes the refractors so desirable there. 


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