Review of the Meade 152ED APO Refractor
[ARTICLEIMGR="1"]The Meade 152ED seems to have never garnered a particularly large following, and yet here is a telescope that most assuredly is capable of providing 100% of at least one of the main big refractor promises: Ultra-sharp, high contrast visual observing.
The Meade 152ED is a physically big refractor. It is an f/9 (1370mm) ED lens design so with the dew shield in place it is quite long. It also uses a 7” outer diameter OTA, so the baffling is some of the most effective I have ever seen on a refractor. The Vixen 102 Achromat I owned also used an oversize tube (114mm O.D.) and it also had superb baffling.
The focuser is a 2.7” unit, though it comes with a 2” adapter in place. While I have never heard a great deal of praise about this focuser in reviews, I would rate it as being among the better focusers in the “Mass-Market” scopes I have used, aside from those with Crayford focusers. For example, I am a big fan of Vixen products, and the Meade 152ED is a bit better than the Vixen refractor focusers I have used. The movement is heavy (though it is lightening up with use), but smooth. I added a couple of drops of Teflon lubricant where I think the rails are, and this also helped. There is also a tiny bit of gear-lash. It asserts itself when attempting to focus at higher powers.
The Meade 152ED is a nicely executed package. Workmanship and finish overall is actually quite good, again appearing equal to or slightly better than Vixen quality. I see that I am using Vixen as the benchmark here, and frankly that seems fair. I regard Vixen as being among the better of the “Mass Market” telescopes, being clearly better than most other mass produced brands, so saying the Meade is similar or slightly better in quality is to me, a compliment considering the price point.
Now I will be honest and say that mine had an optical problem when I purchased it, but some phone calls to Meade, some shipping effort (paid for by Meade), and some patience, and that problem was corrected. When it was received, stars had prism-like appearance, being tinged with red on one side of the Airy disk, white in the center, and blue on the other side. I tried collimation and centering, but these did not correct the problem. Only by returning it to Meade was I able to get the problem rectified.
This scope requires a BIG mount. I have mine on an EQ6 SkyScan mount. This combination is acceptable for visual use, but for imaging, I suspect that a Ci-700 or G-11 would be the minimum that would be considered acceptable. I am compelled to say this… This scope is more demanding to set up than any scope I have owned before. The mount is heavy, and I either have to drop the weights and grunt it out of the house, or further dissemble it to move it. The OTA is LONG. It will not easily fit into most cars unless they are a hatchback, or have a trunk pass-through. This is something of a specialty instrument that requires lots of compromise from the owner. If you haven’t owned a really big refractor before and are considering it, I would say that you should consider these issues carefully. I still struggle with them, and I really do like this telescope. From time to time though, I wonder if I will continue to use as much as I have been lately over the years just because of the set-up and transport issues.
Now, I got here the long way around… I tried smaller refractors. The 102mm APO I owned didn’t wow me at all. Oh sure, it was compact and offered crisp views, but in a nutshell, it was just too small to gather enough light for use in my central Austin TX location. Even the glorious M42 was positively underwhelming. I didn’t find it all that much better than the Orion 127 Mak I owned on many targets (The 4” WAS better though, just not what 5 times the price would suggest it should be). I sold the 4” APO for a Vixen 102 Achromat which I considered to be almost as good, and at a small fraction of the cost. I sold that one too though, because once again, 4 inches of aperture just didn’t cut it for me. I bought a Vixen 140NA refractor for my low power, wide field work, and I have been happier with it than with the 4” APO or Achromat.
I also owned a couple of Celestron CR150 refractors, both of which I found to be very good. Only at higher powers or when viewing solar system targets did chromatic aberration become a problem, and it was a serious problem for me, clearly lowering contrast at high powers on Jupiter and the Moon. The Vixen 102 was almost color-free by comparison. A 6” f/8 achromat lens is going to produce violet at the eyepiece. Lots of it….
But the allure of a big refractor haunted me. I mean, I do indeed “Get” the notion that there is a fine quality to the views delivered by a good refractor, but the smaller refractors I owned lacked the punch I longed for, and the big f/8 achromatic refractors lacked the image fidelity of the smaller APOs.
I had my name on a waiting list for a large high-end APO for several years, but grew frustrated by the wait, and finally decided to purchase a new Meade 152ED. Providence shined on me, as the decision was a good one.
This particular Meade 152ED has some of the better optics of the scopes I have owned. The polish is very smooth, and there are no obvious defects visible in the star test. Spherical Aberration may be present to some tiny degree, because the inside and outside of focus Airy disk patterns look a bit brighter on one side than the other. Still, whatever SA might be present must be of such negligible amount as to be meaningless. IN-focus, the Airy disk is virtually perfect as depicted in star testing charts for un-obstructed telescopes. The Airy disk is a small bright dot, surrounded by an Oh-so-very-faint first diffraction ring. In fact, on dimmer stars, the first diffraction ring is barely visible. Bad seeing conditions will make it a bit more apparent, but for the most part, the in-focus Airy disk is almost perfect. This telescope clearly presents some of the most pleasing stellar views I have ever had. While my 4’ APO presented as-good of an in-focus Airy disk, it just didn’t focus the stars down to such small points. At moderate powers, the 4” Scope started to show stars more like textbook drawings of Airy disks rather than like stars suspended in space. The 6 inch telescope allows them to keep looking like stars at considerably higher powers.
If I remember my book learnin correctly, a refractor with perfect optics will put 84% of the light into the Airy disk, with 7% going into the first diffraction ring, and the remainder going into outer rings that will be to faint to detect on all but the very brightest stars. Now, on this point of having 84% of the available light going into the Airy disk…if you think about it, you will understand why these big refractors seem so special. The main reason is related to the arch-nemesis of obstructed (reflecting) systems:seeing conditions… When seeing is less than perfect, a system with a 25 percent obstruction which is already putting about 20% to 25% (or more) of its light into the first diffraction ring will see more and more of the light being spilled into the successive rings and scattered among them. The result is that in anything less than just about PERFECT seeing, the reflector image will start to break down quicker. My 11” SCT shows this to an extreme degree. It is large (which makes it more affected by seeing because of the nature of the turbulence cells in the atmosphere), it has a big central obstruction (the first diffraction ring around the Airy disk of a perfect SCT will be about as bright as the ring around the Airy disk in a refractor with ¼ wave SA. The net effect is that even though the Airy disk itself is theoretically smaller in the large reflector, typical seeing will spill enough light into the diffraction rings to bloat the image of the star. As a result, on the vast majority of my viewing nights, the Meade 152ED presents much more pleasing views than anything else I own. On EXCEPTIONAL nights (1 in 25 most of the year, 1 in 10 in the Summer), the SCT will present noticably smaller Airy Disks, but even then, they still look somewhat dull when compared to the Meade 152ED. In fact, one book (Telescope Optics: Complete Manual for Amateur Astronomers, by Rutten and Van Venrooij) provides a chart that suggests that a 6” refractor is perhaps one of the best choices for an all around telescope when trying to balance the desire for large aperture against the negative effects of poor seeing. My own experience is now confirming this for me. On many nights, I enjoy the view through the big refractor more than with my NexStar 11 when viewing a large percentage of stellar and solar system subjects. Only when viewing objects such as globular clusters and faint open clusters or galaxies does the bigger reflector show a decisive advantage, and only because it reaches deeper, turning up stars maybe a magnitude fainter, which in a Globular Cluster, translates into a LOT more stars.
Regarding secondary color, well, there simply isn’t any visible on 99.9% of the subjects I have viewed (including Jupiter and Saturn). Some people will say that the Meade 152ED is not an APO, or prefer to call it a “Semi-APO” and I am not at all inclined to argue either point. I will only say that color is so well corrected as to be unnoticeable in normal visual observing. For me, that is enough.
I can see a very faint, very narrow yellow tinge just inside the limb when viewing the Moon off axis in some of my eyepieces, but I think that some of this may come from the eyepieces themselves. It is more pronounced in some eyepiece designs (complex) than in others. On axis, I see practically none at all on the limb, and on the disk itself, I see absolutely no false color. None. Nada.
So, I will call it a “Practically color-free, larger aperture, high quality refractor that is a true pleasure to view with.” And frankly, if you asked me for just a lay-person’s opinion, I would say that I think Meade was justified in using APO in its marketing material. You must remember that this telescope design (and Meade’s accompanying marketing material) was introduced 10 year ago, and when Meade introduced it, by the standards of the day, I believe that it would have easily been accepted as a true APO. Some of the other “APO” scopes from that time also showed a tiny bit of color too, so when I put to it into perspective, I don’t think Meade was misleading with their labeling. I have looked through a couple of very expensive 4” APOs from 10 years ago, and I would say the big Meade is as good, and compared to even the BEST achromats from then and now, it still would be considered color-free.
Ok, so, how is it to view with a practically color-free, larger aperture, high quality refractor??? It is in a word, Sublime. Yes, there is indeed something special about the view through a practically color-free, larger aperture, high quality refractor. The incredible sharpness of stars in the field is hard to describe. People say “Pin-point,” but in an attempt to build artificial stars, I have done many pin-points in foil, and they don’t come close to matching the nature of an in-focus star in the Meade 152ED. On a big cluster like M37, the stars are such finely focused little points of light that they seem impossibly small. On nights of average seeing, the Meade 152ED presents perhaps the most pleasing open-cluster viewing that I have ever enjoyed. My 4” APO didn’t gather but half the light, and the Airy disks, being much larger, didn’t give the same pin-point like impact. Yes, they were excellent, but at even moderate powers, the Airy disk would show, while at similar powers in the 152ED, they still look like tiny points.
Light throughput is excellent. Theory says that light throughput should be a bit less than an 8”SCT, but in side-by-side comparisons on several open clusters, I could not see any stars in my 8” SCT that were not visible in the 6 inch refractor and everything is sharper in the refractor to boot. Now oddly, it will be a bit harder to find a very dim star in the 152ED when doing these comparisons with the C8, again because the star is such an ultra-fine point in the refractor. Once you find it though, it is conspicuous. In the 8”, the star is visible because it presents itself as a larger blob. In the refractor, it presents itself as an oh-so-tiny point, which you have to actually look harder to find it, but once the position is located, suddenly you can’t HELP but seeing it. Odd sensation, really, but this is what I see.
With deep sky objects, the 6” Meade 152ED is probably closer to the Celestron 9.25 inch SCT that I used to own. Now I didn’t really notice that often mentioned difference is sky blackness. When using eyepieces that produce similar magnifications and similar fields of view, I just don’t see the sky as being “Blacker” in the refractor on deep sky objects. And my bet is that the sheer power of aperture in a 9” scope will start to show slightly fainter stars … Ah, but not as sharp… There IS a difference when very bright objects are in the field of view, especially the Moon. On the Moon, there is indeed a darker sky just off of the limb in the 6” refractor. In fact, the sky looks ultra-black in this case, while in the SCT, it starts to show a very faint glow. Similarly, planets will show a tiny faint glow around the planet in the SCTs. Some of this comes from reflections in the eyepiece, and while I couldn’t match powers and eyepiece designs to make an exact comparison, the sky immediately around Jupiter is quite black in the refractor, while there is a faint glow immediately around the planet in the SCT.
Now don’t think that this is a disparagement to the 8” and 9.25” SCT, because an 8” SCT on a computerized mount costs half of the price of the Meade 152ED OTA alone (new), and a C 9.25 OTAs (new) only costs about half of what the 6” refractor OTA would cost. I have incredible respect for these two OTAs and if either budget or overall manageability were my highest priority, either one of these scopes would be VERY difficult to pass by. The 8” SCT on a computerized mount is still my first recommendation for people wanting to enter into amateur astronomy with a mid-sized GEM mounted scope and having a reasonable budget. I own a Celestron 8” SCT that I have on a Meade LXD55 mount, and to this day, it still gives me great satisfaction to use it.
When used with a 35mm Panoptic, the Meade 152ED can provide a 1.7 degree field and it is a spectacular field indeed. Now this field is 1.2 degrees shy of what I can achieve with my Vixen 140 refractor, and of course I can’t reach the same low powers, but the quality of the view in this size field is unsurpassed by anything I have ever owned. The Vixen 140 NA that I own presents an in-focus Airy disk that appears to have about ¼ wavelength of spherical correction error, and it is not quite as bright as the 12mm deficit in aperture would indicate (it is a 4 element design), so that while it does present a very lovely field, the view of similar sized fields in the 6” 152ED is clearly superior. Stars just appear as much smaller, more intense light sources.
Likewise, nothing I have owned can do double stars better on typical nights. On maybe a couple of dozen nights in the year, the NX11 can eek out some incredibly close or high contrast difference doubles, but the Meade 152ED reaches its theoretical performance on MOST nights. On very bright stars, poor seeing will start to affect even this scope. Seeing is MUCH less a factor than with my 11” SCT though.
Deep sky performance, when compared to my NexStar 11, is as you would expect, not as good. Aperture clearly dominates. Still, in a recent trip to dark skies in north Texas, the 6” refractor easily showed the inclusion on M82, and spiral structure on M51, along with the companion. Deep sky views between this and the 11” SCT were more similar than I would have thought they would be. But the larger aperture did prevail on most targets. M13 was more resolved in the larger scope, as was M92. The dust lane in the Sombrero Galaxy was a bit more prominent in the 11” SCT. M37 was much richer in the 11” SCT, though better framed at low power in the 6”. The Ring Nebula (M57) was similar in both, but the wider field of the Meade 152ED could offer a much nicer framing here as well. For some reason, the Ring Nebula is as enjoyable to me at low power as it is at high power. At the same time, though, the crispness of the view in the 6” refractor always seemed better. This is a major point. I SEE more with the larger scope, but the views seem more pleasing in the 6” refractor. I never got this with smaller refractors, again because of the fact that they just didn’t go deep enough, and also because of the issue of the Airy disk sizes.
The Meade comes in second to my NexStar 11 on lunar performance. Seeing again is an important factor, and on nights of average seeing, the 6” refractor usually presents an image that is very close (closer than anything I have owned previously), but the resolution of the much larger instrument just shows more detail. Last night (18 May, 05), the seeing was actually quite good here in central Texas, and in a side-by-side comparison, the NexStar 11 just eeked out a bit more detail everywhere I looked. In past comparisons when seeing conditions weren’t as good though, the Meade 152ED held its own. No other telescope I have ever owned has done so well on the moon when compared to the NexStar 11.
On planets the situation is clouded… Saturn usually looks a tiny bit better in the NexStar 11. With the 11” SCT, I see more evidence of the polar shading, and the Cassini division seems a bit more pronounced as does shading of the rings. The main factor, I think is that image brightness of the Meade 152ED starts to become the limiting factor at about 40x per inch of aperture. Now this is quite good. I have never owned a telescope that could achieve improved performance much above 30x to 35x per inch of aperture on solar system objects. I hear of people using 50x per inch of aperture and more, but frankly, I have never owned a scope that showed me any MORE detail at 50x per inch than at 35x per inch on planets. But the Meade 152ED does work extremely well at 40x per inch of aperture (38x actually, which is 228x with a .66mm exit pupil, using a 6mm Radian). Using a 5mm Radian for 274x (.55mm exit pupil) produces a bigger, more pleasing, but dimmer image, so that while the image is a more comfortable scale, I can’t say that I see additional details. Also, floaters in my eye become a much bigger bother at this exit pupil. But the image is still quite sharp at this magnification. . I would say that no telescope I have owned previously has been able to achieve this kind of magnification ratio. Also, it is a VERY rare night that I can use over about 190x with the big SCT. With the Meade, I can often use the 228x which results in a better exit pupil for detecting low contrast objects, and I do have the ability to go to 274X if I want to get a bit bigger image scale.
In the past, I have owned a few scopes that seemed to present results on Jupiter nearly on par with my 11” SCT (MN61 was closest), but on most nights, if I was patient, I could see more in the larger SCT. Extremely low level contrast detail in the SCT, as mentioned before, is seriously affected by seeing. To get good performance on Jupiter with a large SCT, the seeing has to be almost perfect. In the last year, I have only had perhaps a couple of dozen nights of seeing this good. Still against most telescopes, on most nights, patience would allow the 11” to glimpse detail that was not visible in the smaller scopes. This simply isn’t true when viewing Jupiter and comparing the NX11 with the Meade 152ED. On MOST nights, the Meade 152ED simply provides a consistently better viewing experience on Jupiter than anything I have owned previously. How good? Very good indeed… Detail in the GRS, detail in the turbulent streams following it, ovals, festoons, barges, subtle belts, its all there on nights of even reasonably good seeing. The moons of Jupiter ALWAYS look sharper in the refractor. Now to be fair, when seeing is good for the NexStar 11 (a minimum of a half-formed, in motion first diffraction ring) the big SCT can provide more detail than the Meade 152ED. Most notably, some of the small white ovals in the southern hemisphere don’t resolve as well in the Meade 152ED. Once again, the superior resolution of the big SCT does a great deal to offset the contrast loss imposed by its large central obstruction in the SCT. While contrast IS an important factor in planetary observing, you would do well to not dismiss resolving power. While I have not seen Mars in the 152ED, I have compared the NexStar 11 to several APO refractors during the Mars close approach a couple of years ago, and no refractor I viewed through showed as much detail as the 11” SCT did. The resolution of the larger SCT just totally overpowered the 4” and 6” refractors I viewed through on this moderately high contrast object.
I just didn’t feel as strongly about the appeal of a 4”, $2000 (or more) APO, but at 6 inches and $2500, the argument for a practically color-free, larger aperture, high quality refractor looks far more compelling to me.
I find myself actually picking a “Smaller” scope over a larger one for a fair percentage of my viewing. On many nights, I take out both the NexStar 11 AND the Meade 152ED. Prior to getting the Meade 152ED, if I was only going to take out ONE scope, it would have almost always been the NexStar 11. Now, I find myself taking out the 6” refractor on a single-scope night almost as frequently as the 11” SCT. My Vixen 140NA is sitting idle far more now (though summer is coming and the 140NA is still my favorite wide-field scope). The 152ED doesn’t collect the same amount of light and can’t match the resolution of the larger scope, but the views are just too beautiful to ignore.
So yes, their truly IS strong merit to the argument that large refractors are some of the most enjoyable scopes to view with. And at $2500, the Meade 152ED does indeed provide a practically color-free, larger aperture, high quality refractor viewing experience.
I really, really like this telescope. Can you tell? Reports of issues with quality control and reports of some with maybe less than really good spherical correction (which in my mind might negate the entire value proposition) make it difficult to offer an unrestrained endorsement, but a good example like mine could turn out to be a prized possession. Mine certainly is to me.
My regards,
Ed Moreno
An ENTIRE Marine Corps squad was tragically lost in Iraq in the past week. Several members of that squad were killed by insurgents hiding and shooting from under the floor in a house. When one of the squad members went down, others were either killed or injured when they attempted to rescue the first, which is what we Marines do. A couple of days later, the surviving members of the same squad where killed by a roadside bomb.
My anguish knows no boundary.
My wish is that this war should not have happened, and that you were all safely in the arms of your family or loved ones. I can’t have that wish, so in its place, I offer you my compassion, and my condolences for the buddies and families of the fallen.
And to all of our forces in the middle-east, may the stars in the skies over you guide you home, and to peace. Please come back to the world safe.
The Meade 152ED is a physically big refractor. It is an f/9 (1370mm) ED lens design so with the dew shield in place it is quite long. It also uses a 7” outer diameter OTA, so the baffling is some of the most effective I have ever seen on a refractor. The Vixen 102 Achromat I owned also used an oversize tube (114mm O.D.) and it also had superb baffling.
The focuser is a 2.7” unit, though it comes with a 2” adapter in place. While I have never heard a great deal of praise about this focuser in reviews, I would rate it as being among the better focusers in the “Mass-Market” scopes I have used, aside from those with Crayford focusers. For example, I am a big fan of Vixen products, and the Meade 152ED is a bit better than the Vixen refractor focusers I have used. The movement is heavy (though it is lightening up with use), but smooth. I added a couple of drops of Teflon lubricant where I think the rails are, and this also helped. There is also a tiny bit of gear-lash. It asserts itself when attempting to focus at higher powers.
The Meade 152ED is a nicely executed package. Workmanship and finish overall is actually quite good, again appearing equal to or slightly better than Vixen quality. I see that I am using Vixen as the benchmark here, and frankly that seems fair. I regard Vixen as being among the better of the “Mass Market” telescopes, being clearly better than most other mass produced brands, so saying the Meade is similar or slightly better in quality is to me, a compliment considering the price point.
Now I will be honest and say that mine had an optical problem when I purchased it, but some phone calls to Meade, some shipping effort (paid for by Meade), and some patience, and that problem was corrected. When it was received, stars had prism-like appearance, being tinged with red on one side of the Airy disk, white in the center, and blue on the other side. I tried collimation and centering, but these did not correct the problem. Only by returning it to Meade was I able to get the problem rectified.
This scope requires a BIG mount. I have mine on an EQ6 SkyScan mount. This combination is acceptable for visual use, but for imaging, I suspect that a Ci-700 or G-11 would be the minimum that would be considered acceptable. I am compelled to say this… This scope is more demanding to set up than any scope I have owned before. The mount is heavy, and I either have to drop the weights and grunt it out of the house, or further dissemble it to move it. The OTA is LONG. It will not easily fit into most cars unless they are a hatchback, or have a trunk pass-through. This is something of a specialty instrument that requires lots of compromise from the owner. If you haven’t owned a really big refractor before and are considering it, I would say that you should consider these issues carefully. I still struggle with them, and I really do like this telescope. From time to time though, I wonder if I will continue to use as much as I have been lately over the years just because of the set-up and transport issues.
Now, I got here the long way around… I tried smaller refractors. The 102mm APO I owned didn’t wow me at all. Oh sure, it was compact and offered crisp views, but in a nutshell, it was just too small to gather enough light for use in my central Austin TX location. Even the glorious M42 was positively underwhelming. I didn’t find it all that much better than the Orion 127 Mak I owned on many targets (The 4” WAS better though, just not what 5 times the price would suggest it should be). I sold the 4” APO for a Vixen 102 Achromat which I considered to be almost as good, and at a small fraction of the cost. I sold that one too though, because once again, 4 inches of aperture just didn’t cut it for me. I bought a Vixen 140NA refractor for my low power, wide field work, and I have been happier with it than with the 4” APO or Achromat.
I also owned a couple of Celestron CR150 refractors, both of which I found to be very good. Only at higher powers or when viewing solar system targets did chromatic aberration become a problem, and it was a serious problem for me, clearly lowering contrast at high powers on Jupiter and the Moon. The Vixen 102 was almost color-free by comparison. A 6” f/8 achromat lens is going to produce violet at the eyepiece. Lots of it….
But the allure of a big refractor haunted me. I mean, I do indeed “Get” the notion that there is a fine quality to the views delivered by a good refractor, but the smaller refractors I owned lacked the punch I longed for, and the big f/8 achromatic refractors lacked the image fidelity of the smaller APOs.
I had my name on a waiting list for a large high-end APO for several years, but grew frustrated by the wait, and finally decided to purchase a new Meade 152ED. Providence shined on me, as the decision was a good one.
This particular Meade 152ED has some of the better optics of the scopes I have owned. The polish is very smooth, and there are no obvious defects visible in the star test. Spherical Aberration may be present to some tiny degree, because the inside and outside of focus Airy disk patterns look a bit brighter on one side than the other. Still, whatever SA might be present must be of such negligible amount as to be meaningless. IN-focus, the Airy disk is virtually perfect as depicted in star testing charts for un-obstructed telescopes. The Airy disk is a small bright dot, surrounded by an Oh-so-very-faint first diffraction ring. In fact, on dimmer stars, the first diffraction ring is barely visible. Bad seeing conditions will make it a bit more apparent, but for the most part, the in-focus Airy disk is almost perfect. This telescope clearly presents some of the most pleasing stellar views I have ever had. While my 4’ APO presented as-good of an in-focus Airy disk, it just didn’t focus the stars down to such small points. At moderate powers, the 4” Scope started to show stars more like textbook drawings of Airy disks rather than like stars suspended in space. The 6 inch telescope allows them to keep looking like stars at considerably higher powers.
If I remember my book learnin correctly, a refractor with perfect optics will put 84% of the light into the Airy disk, with 7% going into the first diffraction ring, and the remainder going into outer rings that will be to faint to detect on all but the very brightest stars. Now, on this point of having 84% of the available light going into the Airy disk…if you think about it, you will understand why these big refractors seem so special. The main reason is related to the arch-nemesis of obstructed (reflecting) systems:seeing conditions… When seeing is less than perfect, a system with a 25 percent obstruction which is already putting about 20% to 25% (or more) of its light into the first diffraction ring will see more and more of the light being spilled into the successive rings and scattered among them. The result is that in anything less than just about PERFECT seeing, the reflector image will start to break down quicker. My 11” SCT shows this to an extreme degree. It is large (which makes it more affected by seeing because of the nature of the turbulence cells in the atmosphere), it has a big central obstruction (the first diffraction ring around the Airy disk of a perfect SCT will be about as bright as the ring around the Airy disk in a refractor with ¼ wave SA. The net effect is that even though the Airy disk itself is theoretically smaller in the large reflector, typical seeing will spill enough light into the diffraction rings to bloat the image of the star. As a result, on the vast majority of my viewing nights, the Meade 152ED presents much more pleasing views than anything else I own. On EXCEPTIONAL nights (1 in 25 most of the year, 1 in 10 in the Summer), the SCT will present noticably smaller Airy Disks, but even then, they still look somewhat dull when compared to the Meade 152ED. In fact, one book (Telescope Optics: Complete Manual for Amateur Astronomers, by Rutten and Van Venrooij) provides a chart that suggests that a 6” refractor is perhaps one of the best choices for an all around telescope when trying to balance the desire for large aperture against the negative effects of poor seeing. My own experience is now confirming this for me. On many nights, I enjoy the view through the big refractor more than with my NexStar 11 when viewing a large percentage of stellar and solar system subjects. Only when viewing objects such as globular clusters and faint open clusters or galaxies does the bigger reflector show a decisive advantage, and only because it reaches deeper, turning up stars maybe a magnitude fainter, which in a Globular Cluster, translates into a LOT more stars.
Regarding secondary color, well, there simply isn’t any visible on 99.9% of the subjects I have viewed (including Jupiter and Saturn). Some people will say that the Meade 152ED is not an APO, or prefer to call it a “Semi-APO” and I am not at all inclined to argue either point. I will only say that color is so well corrected as to be unnoticeable in normal visual observing. For me, that is enough.
I can see a very faint, very narrow yellow tinge just inside the limb when viewing the Moon off axis in some of my eyepieces, but I think that some of this may come from the eyepieces themselves. It is more pronounced in some eyepiece designs (complex) than in others. On axis, I see practically none at all on the limb, and on the disk itself, I see absolutely no false color. None. Nada.
So, I will call it a “Practically color-free, larger aperture, high quality refractor that is a true pleasure to view with.” And frankly, if you asked me for just a lay-person’s opinion, I would say that I think Meade was justified in using APO in its marketing material. You must remember that this telescope design (and Meade’s accompanying marketing material) was introduced 10 year ago, and when Meade introduced it, by the standards of the day, I believe that it would have easily been accepted as a true APO. Some of the other “APO” scopes from that time also showed a tiny bit of color too, so when I put to it into perspective, I don’t think Meade was misleading with their labeling. I have looked through a couple of very expensive 4” APOs from 10 years ago, and I would say the big Meade is as good, and compared to even the BEST achromats from then and now, it still would be considered color-free.
Ok, so, how is it to view with a practically color-free, larger aperture, high quality refractor??? It is in a word, Sublime. Yes, there is indeed something special about the view through a practically color-free, larger aperture, high quality refractor. The incredible sharpness of stars in the field is hard to describe. People say “Pin-point,” but in an attempt to build artificial stars, I have done many pin-points in foil, and they don’t come close to matching the nature of an in-focus star in the Meade 152ED. On a big cluster like M37, the stars are such finely focused little points of light that they seem impossibly small. On nights of average seeing, the Meade 152ED presents perhaps the most pleasing open-cluster viewing that I have ever enjoyed. My 4” APO didn’t gather but half the light, and the Airy disks, being much larger, didn’t give the same pin-point like impact. Yes, they were excellent, but at even moderate powers, the Airy disk would show, while at similar powers in the 152ED, they still look like tiny points.
Light throughput is excellent. Theory says that light throughput should be a bit less than an 8”SCT, but in side-by-side comparisons on several open clusters, I could not see any stars in my 8” SCT that were not visible in the 6 inch refractor and everything is sharper in the refractor to boot. Now oddly, it will be a bit harder to find a very dim star in the 152ED when doing these comparisons with the C8, again because the star is such an ultra-fine point in the refractor. Once you find it though, it is conspicuous. In the 8”, the star is visible because it presents itself as a larger blob. In the refractor, it presents itself as an oh-so-tiny point, which you have to actually look harder to find it, but once the position is located, suddenly you can’t HELP but seeing it. Odd sensation, really, but this is what I see.
With deep sky objects, the 6” Meade 152ED is probably closer to the Celestron 9.25 inch SCT that I used to own. Now I didn’t really notice that often mentioned difference is sky blackness. When using eyepieces that produce similar magnifications and similar fields of view, I just don’t see the sky as being “Blacker” in the refractor on deep sky objects. And my bet is that the sheer power of aperture in a 9” scope will start to show slightly fainter stars … Ah, but not as sharp… There IS a difference when very bright objects are in the field of view, especially the Moon. On the Moon, there is indeed a darker sky just off of the limb in the 6” refractor. In fact, the sky looks ultra-black in this case, while in the SCT, it starts to show a very faint glow. Similarly, planets will show a tiny faint glow around the planet in the SCTs. Some of this comes from reflections in the eyepiece, and while I couldn’t match powers and eyepiece designs to make an exact comparison, the sky immediately around Jupiter is quite black in the refractor, while there is a faint glow immediately around the planet in the SCT.
Now don’t think that this is a disparagement to the 8” and 9.25” SCT, because an 8” SCT on a computerized mount costs half of the price of the Meade 152ED OTA alone (new), and a C 9.25 OTAs (new) only costs about half of what the 6” refractor OTA would cost. I have incredible respect for these two OTAs and if either budget or overall manageability were my highest priority, either one of these scopes would be VERY difficult to pass by. The 8” SCT on a computerized mount is still my first recommendation for people wanting to enter into amateur astronomy with a mid-sized GEM mounted scope and having a reasonable budget. I own a Celestron 8” SCT that I have on a Meade LXD55 mount, and to this day, it still gives me great satisfaction to use it.
When used with a 35mm Panoptic, the Meade 152ED can provide a 1.7 degree field and it is a spectacular field indeed. Now this field is 1.2 degrees shy of what I can achieve with my Vixen 140 refractor, and of course I can’t reach the same low powers, but the quality of the view in this size field is unsurpassed by anything I have ever owned. The Vixen 140 NA that I own presents an in-focus Airy disk that appears to have about ¼ wavelength of spherical correction error, and it is not quite as bright as the 12mm deficit in aperture would indicate (it is a 4 element design), so that while it does present a very lovely field, the view of similar sized fields in the 6” 152ED is clearly superior. Stars just appear as much smaller, more intense light sources.
Likewise, nothing I have owned can do double stars better on typical nights. On maybe a couple of dozen nights in the year, the NX11 can eek out some incredibly close or high contrast difference doubles, but the Meade 152ED reaches its theoretical performance on MOST nights. On very bright stars, poor seeing will start to affect even this scope. Seeing is MUCH less a factor than with my 11” SCT though.
Deep sky performance, when compared to my NexStar 11, is as you would expect, not as good. Aperture clearly dominates. Still, in a recent trip to dark skies in north Texas, the 6” refractor easily showed the inclusion on M82, and spiral structure on M51, along with the companion. Deep sky views between this and the 11” SCT were more similar than I would have thought they would be. But the larger aperture did prevail on most targets. M13 was more resolved in the larger scope, as was M92. The dust lane in the Sombrero Galaxy was a bit more prominent in the 11” SCT. M37 was much richer in the 11” SCT, though better framed at low power in the 6”. The Ring Nebula (M57) was similar in both, but the wider field of the Meade 152ED could offer a much nicer framing here as well. For some reason, the Ring Nebula is as enjoyable to me at low power as it is at high power. At the same time, though, the crispness of the view in the 6” refractor always seemed better. This is a major point. I SEE more with the larger scope, but the views seem more pleasing in the 6” refractor. I never got this with smaller refractors, again because of the fact that they just didn’t go deep enough, and also because of the issue of the Airy disk sizes.
The Meade comes in second to my NexStar 11 on lunar performance. Seeing again is an important factor, and on nights of average seeing, the 6” refractor usually presents an image that is very close (closer than anything I have owned previously), but the resolution of the much larger instrument just shows more detail. Last night (18 May, 05), the seeing was actually quite good here in central Texas, and in a side-by-side comparison, the NexStar 11 just eeked out a bit more detail everywhere I looked. In past comparisons when seeing conditions weren’t as good though, the Meade 152ED held its own. No other telescope I have ever owned has done so well on the moon when compared to the NexStar 11.
On planets the situation is clouded… Saturn usually looks a tiny bit better in the NexStar 11. With the 11” SCT, I see more evidence of the polar shading, and the Cassini division seems a bit more pronounced as does shading of the rings. The main factor, I think is that image brightness of the Meade 152ED starts to become the limiting factor at about 40x per inch of aperture. Now this is quite good. I have never owned a telescope that could achieve improved performance much above 30x to 35x per inch of aperture on solar system objects. I hear of people using 50x per inch of aperture and more, but frankly, I have never owned a scope that showed me any MORE detail at 50x per inch than at 35x per inch on planets. But the Meade 152ED does work extremely well at 40x per inch of aperture (38x actually, which is 228x with a .66mm exit pupil, using a 6mm Radian). Using a 5mm Radian for 274x (.55mm exit pupil) produces a bigger, more pleasing, but dimmer image, so that while the image is a more comfortable scale, I can’t say that I see additional details. Also, floaters in my eye become a much bigger bother at this exit pupil. But the image is still quite sharp at this magnification. . I would say that no telescope I have owned previously has been able to achieve this kind of magnification ratio. Also, it is a VERY rare night that I can use over about 190x with the big SCT. With the Meade, I can often use the 228x which results in a better exit pupil for detecting low contrast objects, and I do have the ability to go to 274X if I want to get a bit bigger image scale.
In the past, I have owned a few scopes that seemed to present results on Jupiter nearly on par with my 11” SCT (MN61 was closest), but on most nights, if I was patient, I could see more in the larger SCT. Extremely low level contrast detail in the SCT, as mentioned before, is seriously affected by seeing. To get good performance on Jupiter with a large SCT, the seeing has to be almost perfect. In the last year, I have only had perhaps a couple of dozen nights of seeing this good. Still against most telescopes, on most nights, patience would allow the 11” to glimpse detail that was not visible in the smaller scopes. This simply isn’t true when viewing Jupiter and comparing the NX11 with the Meade 152ED. On MOST nights, the Meade 152ED simply provides a consistently better viewing experience on Jupiter than anything I have owned previously. How good? Very good indeed… Detail in the GRS, detail in the turbulent streams following it, ovals, festoons, barges, subtle belts, its all there on nights of even reasonably good seeing. The moons of Jupiter ALWAYS look sharper in the refractor. Now to be fair, when seeing is good for the NexStar 11 (a minimum of a half-formed, in motion first diffraction ring) the big SCT can provide more detail than the Meade 152ED. Most notably, some of the small white ovals in the southern hemisphere don’t resolve as well in the Meade 152ED. Once again, the superior resolution of the big SCT does a great deal to offset the contrast loss imposed by its large central obstruction in the SCT. While contrast IS an important factor in planetary observing, you would do well to not dismiss resolving power. While I have not seen Mars in the 152ED, I have compared the NexStar 11 to several APO refractors during the Mars close approach a couple of years ago, and no refractor I viewed through showed as much detail as the 11” SCT did. The resolution of the larger SCT just totally overpowered the 4” and 6” refractors I viewed through on this moderately high contrast object.
I just didn’t feel as strongly about the appeal of a 4”, $2000 (or more) APO, but at 6 inches and $2500, the argument for a practically color-free, larger aperture, high quality refractor looks far more compelling to me.
I find myself actually picking a “Smaller” scope over a larger one for a fair percentage of my viewing. On many nights, I take out both the NexStar 11 AND the Meade 152ED. Prior to getting the Meade 152ED, if I was only going to take out ONE scope, it would have almost always been the NexStar 11. Now, I find myself taking out the 6” refractor on a single-scope night almost as frequently as the 11” SCT. My Vixen 140NA is sitting idle far more now (though summer is coming and the 140NA is still my favorite wide-field scope). The 152ED doesn’t collect the same amount of light and can’t match the resolution of the larger scope, but the views are just too beautiful to ignore.
So yes, their truly IS strong merit to the argument that large refractors are some of the most enjoyable scopes to view with. And at $2500, the Meade 152ED does indeed provide a practically color-free, larger aperture, high quality refractor viewing experience.
I really, really like this telescope. Can you tell? Reports of issues with quality control and reports of some with maybe less than really good spherical correction (which in my mind might negate the entire value proposition) make it difficult to offer an unrestrained endorsement, but a good example like mine could turn out to be a prized possession. Mine certainly is to me.
My regards,
Ed Moreno
An ENTIRE Marine Corps squad was tragically lost in Iraq in the past week. Several members of that squad were killed by insurgents hiding and shooting from under the floor in a house. When one of the squad members went down, others were either killed or injured when they attempted to rescue the first, which is what we Marines do. A couple of days later, the surviving members of the same squad where killed by a roadside bomb.
My anguish knows no boundary.
My wish is that this war should not have happened, and that you were all safely in the arms of your family or loved ones. I can’t have that wish, so in its place, I offer you my compassion, and my condolences for the buddies and families of the fallen.
And to all of our forces in the middle-east, may the stars in the skies over you guide you home, and to peace. Please come back to the world safe.
Funding Member
