INTRODUCTION

I decided to put these two high-end telescopes head to head and share some insight that most observers may not even be aware of. I seldom sell telescopes and keep most of the ones I acquire, so I have several different types of high-end models to choose from. Most of us know that no telescope is perfect, so having choices makes things easier. So, why would anybody compare a 6″ telescope to a 14.5″ telescope? The main reason is because each design does something the other one can’t. Most observers are quick to adopt the idea that aperture rules. Such a foolish statement. This cliché has been passed around forums quite carelessly with little or no regard to the issues that come with aperture. Aperture may rule in some cases, but it doesn’t apply to everything, and not every top quality telescope is flawless either.

REFRACTOR OR REFLECTOR

Comparing a refractor to a reflector is like comparing a road car to an off road car. When it comes to resolving fine details in globular clusters, galaxies, planetary nebula, selected nebula and certain open clusters, the 14.5″ Starmaster wins hands down. It’s greater resolving power simply allows it to excel in these areas of deep sky observation. It can also out-perform any refractor on multiple stars as well as the Moon and planets “BUT” not without some inherent issues that plague its contrast in a major way and I’m not just talking about boundary layer at the primary either. Here, the larger reflector will not appear to perform as consistently as the refractor no matter how good the optics. Some objects will appear to take on a processed or noisier appearance while the refractor, although dimmer, makes every target appear completely natural an unaltered.

The refractor will more often than not, surpass the larger reflector on extended nebula, extended star clusters, multiple stars, and produce wide field vistas of the Milky Way that a larger reflector would be completely unable to compete with. More often than not, it can also outperform the larger reflector on the Moon & planets in just about every manner for specific reasons we will discuss. A refractor like the FS152, simply by its nature has unparalleled contrast that few reflectors could possibly match.

A dark sky with the exception of the moon and planets is a far better substitute than any amount of aperture when it comes to viewing deep sky targets. There’s also something else that’s extremely appealing about a refractor like the FS152. I’m sure some of you will understand that you get the feeling like you’re actually looking through a real telescope with a conventional tripod, like something you saw in a textbook or classic sci-fi movie when you were a kid. That feeling is something that no dobsonian design can rival.

When you are sitting down in a chair, relaxed, using a precision mount, you can really focus and concentrate on what you’re viewing. I’m sure many of you could share countless experiences and opinions regarding the attributes of each design but these are just a few to consider.

SO HOW DO YOU KNOW WHAT TELESCOPE YOU SHOULD HAVE?

The simple answer is do not look for absolution in any one telescope, as you will most likely never find it. Just collect as many different telescopes as you can afford so you can make the choice that best suits your wants at the time. If you don’t have enough money, then you will have to learn what questions to ask yourself in order to make the best choice to suit your observing wants.

STARMASTER 14.5″ HYBRID

Starmaster telescopes are arguably some of the finest dobsonians in the industry. Rick Singmaster is a stickler for optical quality in fact he is quite adamant about making sure it’s just right before letting a telescope go out the door. Part of what has made this easier is Carl Zambuto, who is arguably one of the finest and most consistent mirror makers in the industry. This combination of dedication is a wonderful mix.

The Starmaster Hybrid is a really fast F-4.3 reflector. Telescopes of this nature will usually benefit from a coma corrector to increase contrast around the outer visual periphery. This will allow stars to appear as points, nearly all the way across the field of view with minor side effects on axis except for the most demanding purists.

This particular model has goto and uses the latest XP4 Sky Commander DSC for its deep sky navigating and can be updated at any time. The goto drive is practically silent and exclusive to Starmaster. In order to move the telescope manually with your hands for star hopping, you must first make sure both the altitude and azimuth clutches are disengaged. As long as the telescope has been aligned to two stars, the computer will not lose memory on where it’s pointing in the sky during this procedure. The clutches can later be reengaged at any time without the need for realignment. The hand paddle has several features which are nice for fast slewing or fine centering of objects. It’s pretty nice to have a dobsonian of this aperture with features like this when you realize it tracks as well. You also do most of your observations without any ladders, a big plus.

There are some pros and cons with regard to the Sky Commander XP4. I’ve been viewing deep sky objects for many years and enjoy observing elusive targets. To me, the database is still very limited when compared to the Argo Navis. For example, let’s say you are using a popular book like the Night Sky Observers Guide and you decide to view all the objects in one particular constellation, also known as constellation mopping. Some constellations cannot be completely mopped and you are left to move on to another constellation prematurely.

The Night Sky Observing Guide has an almost inexhaustible object list and yet, there are several catalogues it has that the Sky Commander does not. I wouldn’t mind this so much were it not for the next issue. Even if you enter the RA and DEC coordinates provided by these references, the Sky Commander does not allow you to enter an accurate enough decimal for its declination axis in particular without some careful thought. This proved to be quite debilitating with regard to the accuracy and confidence I had that I found my target. Although you can store and even download a limited number of objects of your choice, I still think it would have been nice to have them installed already, especially for a telescope of this caliber.

I suppose the next step will be to use the Pocket Sky. Once you have found an object of

interest with the Sky Commander, you simply press the enter key and press the goto key on the hand control and away it goes. Regardless of some of the cons, this telescope is super user friendly and the drive system is amazingly smooth. The focuser on the Starmaster is beautiful too. It uses the Feather Touch focuser by Starlight Instruments, which have become very popular these days.

MIRROR CELL

This is something I always check with dobsonians. The mirror cell in this telescope is very nice. Metal cable slings have received excellent ratings with regard to edge support but there are a few key features consumers are rarely aware of. The biggest one is how the edge supports behave, relative to the flotation points that support and move the primary mirror forward and backward while collimating the telescope. An issue I’ve seen in some competing designs is the use of a sling that does not move in unison with the flotation points. This can cause binding, shifting or pinching of the mirror and even cause the mirror to get hung against the side support pins in some cases, depending on their position. I’ve even seen where some telescopes have to be pointed vertical to get the primary mirror to drop back down. The Starmaster uses a flotation, edge support but more importantly, the edge support and rear flotation points all move in unison, the way a proper cell should behave.

Collimation is held in place quite firmly without the issues of flexure. I placed a laser collimator in the focuser and watched the red dot on the primary to see if it shifted out of the bull’s-eye as I moved the altitude up and down and it stayed centered. This is a common problem not often mentioned in reviews because it either gets overlooked or ignored. This is something I always check in a dob to help verify if it’s coming from a lack of strength from the secondary support, the mirror cell or the truss design, etc. Overall, the Hybrid is a solid, little system.

The secondary is adjusted with four thumbscrews that are quite smooth when turning and they hold collimation extremely well. Wood structures in general sometimes have a tendency to expand and contract in various temperatures, so it isn’t a bad idea to check collimation a couple of hours into the observing session. For the most part, I’m impressed with the Starmaster in that regard.

OPTICAL PERFORMANCE

The optical performance on deep sky targets in the Starmaster are wonderful and in some cases, even stunning, especially when you consider that this has a 14.5″ mirror. Newbie’s should understand that no matter how well figured a mirror is, the coma is inherent in a system this fast. With the coma corrector in place, stars appear like small points on nights of good seeing and their colors shine vividly. We also commonly forget that a good secondary mirror is also a crucial element of the optical train. Don’t under estimate the secondary. During several star tests I conducted, the patterns appeared concentric, clean and practically identical on both sides of focus without any bothersome issues of astigmatism or spherical aberration. To me, it’s just another typical Zambuto. Star clusters like NGC7789 and M11 appear like salt sprinkles with dark backgrounds. Galaxies, planetary nebula and various types of objects shine beautifully through this telescope.

PLANETARY PERFORMANCE AND THERMAL ISSUES

There’s no doubt that Starmaster’s are good planetary telescopes, even with their fast optics. There have been a number of reports of this from the most reputable and well-known obs

ervers. But how consistent are these planetary images, really? The Starmaster is not without its issues and it has a major one I’m about to discuss.

One of the biggest oversights regarding not just one, but literally all ATM’s who specialize in large dobsonians, is focuser placement. It has destroyed everything I’ve paid the extra money to defeat, mainly the quality of the image you get with planets. Just go to the galleries of all the big ATM’s and see for yourself what side their focusers are placed on. None of them are on the left hand side of the upper cage assembly. It’s as if they all copy each other without any regard to the dire thermal consequences, a HUGE mistake for some planetary enthusiasts!

In order to picture a focuser on the right hand side, imagine standing in front of the telescope looking down the tube. In this case, the focuser would appear on your left. If you were standing behind the telescope looking up the tube, the focuser would then appear to be on the right. An ATM can put the focuser on the left side or right side of the upper cage assembly but, putting one on the right side all the time as every ATM does is like asking a right handed golfer to play with their left hand all the time. This focuser placement has serious side effects with your body currents when using higher magnifications on stars and planets depending on your viewing location.

It stuns me to see how much observers obsess over optics, yet give little or literally no regard to this very serious problem. Imagine all the time and effort put into a finely figured set of mirrors in a wonderfully crafted telescope, only to have the images degraded because of a faulty focuser placement. Just to give you a perspective of the seriousness of the issue, professional observatories that allow public tours, require that all occupants leave by a certain time. Why is this? Because humans are a major source of heat plumes, and domes have to be acclimated so their sensitive cameras can do their work properly. Viewing planets and tight, multiple stars at high magnifications in an amateur telescope are also sensitive in the same way.

Now imagine an open truss tube and you’re savoring every second of the precious seeing to resolve the most spectacular planetary detail and you’re standing right next to a completely open optical path and BTW, a typical light shroud will not stop it! This will have profound consequences on the image quality and this can easily be proven. ATM’s should always offer focuser placement as an option to the consumer, especially if they are planetary and double star enthusiasts paying thousands of dollars. Unfortunately Starmaster does not offer this option despite several suggestions I’ve made. I’ve even discussed the issue for years in forums and have even given lectures on the topic at public events.

HERE’S HOW TO PROVE THIS FOR YOURSELF

You can conduct this experiment with an out of focus eyepiece but nothing makes it more obvious than a barlow lens and a binoviewer. This method produces one of the most remarkable and clear pictures of the schlieren or streak test in vivid detail. For this test, do not use any eyepieces with your binoviewer. First, point your telescope on a planet or a really bright star. The Moon itself is too bright in case you’re wondering. Center the object carefully, so you can get a clear picture of the secondary spider vane with the illuminated light in the background. Just as an experiment, hold your hand in front of the optical path and you can see your body currents pouring off like fire plumes!

Even if you are using a thick, down glove or jacket, it will not stop these heat plumes from occurring. The boundary layer will appear to move slowly, like ripples on a pond in various directions while bad seeing will display itself as a fast, flowing stream in one direction. It’s up to you to teach yourself what each movement of air represents. Body currents will usually pour across the field, depending on the direction the telescope is pointed, relative to you.

We are all a major source of heat, like a furnace. When that heat is exposed to the cold, the difference in temperature is what causes the plumes. Remember those helicopter cameras that the military and police use to catch the bad guys in the dark? They appear as a heat source on their monitor. That’s how much heat humans give off.

COMPARING THE TAK AND STARMASTER ON JUPITER AND THERMAL ISSUES

During this shootout, my observing buddy John Curry and I put the Takahashi FS152 next to the Starmaster for a shootout. While John observed through the 6″ Tak, I observed with the Starmaster on a night of excellent seeing. No matter what magnification we used, more often than not, I was continually getting blurred or softened images in the Starmaster at precisely the same time John was not in the FS152! This occurred over the course of the entire evening. Most observers would probably dismiss it as bad optics, central obstruction, thermal behavior at the primary mirror or various fluctuations in seeing if they didn’t know any better.

So, the lesson here is that YOU are also a major source of the thermal problem. Bigger aperture isn’t going to compete with a world-class refractor on the planets if the focuser isn’t on the correct side for your viewing location, not to mention the other serious issues reflectors are plagued with. So, aperture does not always rule.

John and I both watched while the FS152 continually pulverized the Starmaster on Jupiter, producing consistently tack sharp images with vivid surface detail, a truly beautiful sight! Jupiter’s moons were nothing short of sensational, appearing like tiny, little pin-balls. You could also make out their relative sizes in the FS152 while the Starmaster’s were harder to define. Sure, there were a couple of moments where the Starmaster was amazingly tack sharp on Jupiter with vivid colors and surface detail, but they were no where nearly as consistent as the Tak and it’s hard to concentrate with distractions like that. Concentration and relaxation are key to seeing more detail.

There was one time where we switched scopes and John yelled out that the Starmaster was amazing on Jupiter, then I quickly ran over to get a peek and by the time I saw it, the sharpness was gone. Rarely ever did this happen with the refractor. When I removed the eyepieces from the binoviewer in the refractor to see the thermal behavior, the picture was perfectly clean, no thermals at all!

When we compare the mountain of challenges a reflector must face in the field to what a refractor must face, it’s literally like comparing an elephant to a flea. So many things can go wrong with a reflector while practically nothing can go wrong with a refractor. Fortunately for the Starmaster, most of it is very well designed but the focuser placement is a major blunder for observers on the west coast and a truly frustrating one to say the least.

UNDERSTANDING THE DIRECTION OF YOUR SEEING CONDITIONS AND YOUR FOCUSER POSITION

The focuser placement for my circumstance may not be the same for yours. In order to determine what side the focuser should be on depends on what direction the air moves when your seeing conditions are good. And you need to learn that first. Here on the west coast, the on-shore breeze only occurs when the airflow moves from the south-west to the north-east or west to east. Since the planets in North America rise in the east and usually transit towards the south, think about what’s happening with a focuser that’s positioned on the right hand side of the upper cage assembly. The results are a disaster.

Your body is now tragically positioned upwind, relative to the position of the planets you are viewing. This consistent breeze is carrying your body currents directly across the optical path. Now, let’s imagine the focuser on the left side of the upper cage. Now your body is positioned downwind and the air will carry your body currents away from the telescope instead of across. Have you ever seen a golfer throw grass in the air? This is so they have a better idea which way the air is moving and the same thing applies to telescopes, it’s no different.

SOLUTIONS?

So you ask, why not just rotate the upper cage? Because the focuser board on this Starmaster is angled slightly upward on the right hand side. If you rotate the upper cage so the focuser is on the left side, the focus board is now angled downward along with the finder. Why not rebuild the upper cage? Why not use a special shroud material or an extended light baffle? Why not use a large fan to suck or blow body currents away from the telescope?

Well you know what? I have a better solution. Just put the focuser on the correct side of the upper cage and it’s done! No more fussing! The rest is counter-intuitive and it’s a lot of unnecessary work anyway. Telescopes of this caliber should always be made to order, not the other way around.

Another issue is fans. Starmaster does not provide you with any primary mirror fans, which speed up the acclimating process in colder temperatures, so be prepared to install your own. This Hybrid has Floyd Blue fans installed with variable speed control and they work excellent.

TAKAHASHI FS152 / EM200 TEMMA II

Oh do I ever love Takahashi! The Japanese are a truly dedicated culture when it comes to their telescopes. There’s practically nothing to be desired after owning one of these. It’s like owning the finest pocket watch money can buy. Whether it’s an astrograph for shooting the night sky or visual intimacy, it all ends here for me. Takahashi makes my favorite telescopes in the world and as far as I’m concerned, nobody does it better.

To me, the FS152 is still the finest 6″ refractor in the world. It’s also one of the most incredible telescopes I’ve ever owned in my life, not just because the images have so much contrast, but because they are consistently beautiful. Just set it up and it works every time. No fussing with collimation, thermals, fans, body currents, focuser placements, etc. To this day, given the choice of any 6″ refractor currently available, I would still pick this particular model over any other, even if I had to pay more money for it. It has several advantages going for it that most consumers are not aware of. One of those advantages is the fact that the lenses can be taken c

ompletely apart, cleaned, put back together again and collimated right at home without any sophisticated equipment. Takahashi has a simple collimator that will help you do the job on your own.

I’m not suggesting you do this but should anything happen to the lenses in a triplet, be ready to pack it up and ship it back for tuning. You will not be tuning it yourself if the glass elements shift out of alignment, especially during shipment. Another issue is consistency. I’ve tested countless triplets and finding a really good one for planets is like shopping for a straight 2×4 in a stack of lumber. These simple doublets were easier to produce and more forgiving to work with than triplets.

I’ve also had this refractor right next to two different world-class 8″ refractors from TEC and TMB and about the only differences detectable, were that the images in the 8’s were slightly brighter or larger. Even the 8″ owners were stunned. Being that the FS152’s focal length is 1216mm’s means that it’s also an F-8. But, what’s even better is that it’s still a relatively wide field instrument. The stars are crisp and pure across the whole field while viewing with high quality, wide field eyepieces at this focal ratio.

It’s also just a fluorite crystal doublet, making it extremely lightweight compared to most triplets and therefore, much easier to mount solidly. You don’t have to lug a massive mount around if you want to travel with it. It also acclimates quickly, being a simple doublet with thinner, shallow optical curves. An 8” triplet can take as long as three hours to hit its optimal performance. This particular doublet was star tested after being exposed to a temperature difference of 30 degree F. The immediate star test revealed serious under correction and reached the null in exactly 65 minutes. That’s fantastic when you consider how much temperature variance it was exposed to!

Another issue I have with triplets is their weird looking appearance when you balance them on the DEC axis. You pay $15,000 to $20,000 dollars for a nice 6” setup and the optical tube assembly looks like it slid backwards in the tube rings. You later realize that this is how they look when they are properly balanced. Some companies offer counter weight tube rings, but once again this adds, more unwanted mass. These are just several advantages the FS152 doublet has over any other for visual observers.

COLOR CORRECTION AND CONFUSION

Many observers prematurely obsess over color correction without realizing its place or even worse, without having any actual experience behind an eyepiece with various refractive designs. They read about different glass and all the sudden, they make premature choices. Remember that a camera picks up light differently than the human eye. Cameras saturate light, while the human eye is not as sensitive to colors as a camera. If you leave a camera exposed long enough using a state of the art apo triplet, you could eventually see false color at some point on brighter stars. Sure, you may see a tinge of very minor false color on Vega with the FS152, but just about everything including planets, are color free to the human eye most of the time.

Another common mistake I read is observers using the edges of the Moon as a guide to revealing false colors. You can do that but you have to be careful. False color can occur even while using a Newtonian with an eyepiece in place. I’ve seen this many times, even with a Newtonian reflector.

The issue occurs in the air with a color dispersion associated with Earth’s atmosphere. Sometimes when objects are being viewed slightly closer to the horizon, you will often see a reddish fringe on the lower side of a planet and a greenish, or bluish fringe on the upper side. An observer could easily mistake this as an issue regarding the telescope’s color correction without even realizing the actual cause. This is the same phenomenon that causes the Sun to still appear on the horizon at sunset, when in actuality, it’s already below the horizon. If you are a big double star fan and you’re seeing all kinds of atmospheric turbulence and false colors for example, take a #25 red filter and watch what happens.

The FS152 puts pl

anets and stars on a very serious diet and will easily compete with any 6″ refractor sold today regardless of price. Sadly, it’s is no longer in production. This model utilizes a 4″ focuser and has some truly fantastic options. In order for it to come to focus, it needs a 3″ extension tube. Instead of using this extension tube, the space is occupied by a Moonlite focuser with a fine focus that simply screws on the back of the tube with the aid of a Takahashi adapter. I had no intension of removing the stock focuser because I wanted to preserve its value and originality. Telescopes like these are investments.

Another plus is that the FS152 has enough in-travel to allow a completely sealed 2″ filter wheel in conjunction with a 2″ star diagonal. I can quickly flip through each filter from broadband to narrow and OIII to determine which one provides the best view in seconds!

The EM200 Temma II is another high quality product from Takahashi. I love this mount as much as I love the telescope. It moves with high precision and the polar scope is second to none! As a test one evening, I did a polar alignment. After completing the polar alignment, I took a cross hair reticle eyepiece and pointed the telescope on a star at 215x. I centered on a star towards the south and went into the house for 15 minutes to make some coffee and came back outside and it was still dead center, over the cross hair. Sure, there are software programs for polar aligning but it’s still a time consuming process and it’s mainly for photography. I’d just rather polar align and be done.

EM200 TEMMA MYTHS

Some myths have floated through the internet about the EM200 I’d like to clarify. One is that it only runs on 24 volts which is not true. The fact that you can run the mount on 24 volts is just an added bonus feature and it should be considered it a luxury. Running it with the 24 volt converter simply allows the mount to slew at twice the speed it normally would. You can easily run it at 12 volts, but it will move at half the slew rate, that’s all. The only reason I usually run the EM200 at 12 volts is because it draws less current from my battery. I have an AC outlet on my particular battery.

Another myth is that the EM200 does not have a goto hand control. The EM200 does have a goto hand control. The only difference is that it’s optional. There are two hand held DSC computers you can purchase for the EM200 and I use both. The first one is the original Temma II DSC produced by Takahashi. Although it’s discontinued, you can still find them floating around on the used market for a few hundred dollars. Sadly, this DSC received a lot of criticism from consumers because of its extremely limited database. It also uses yellow LED’s instead of red. Maybe the technicians at Tak had a fondness for colors at the time, I don’t know.

Even though this computer and the Sky Commander have limited databases, there’s one advantage this controller has that most observers overlook. If you’re using the Night Sky Observers Guide for example, you can enter RA and DEC coordinates very accurately for all the obscure catalogs, unlike the Sky Commander. Takahashi also offered a newer, optional, hand held IPAQ with Pocket Sky by Software Bisque. There’s also a wireless Bluetooth option and everything else is already, programmed by Takahashi. All you have to do is plug it in, no different than plugging in any other handset on a modern computerized telescope that’s already been programmed. I’ve also been informed that Takahashi is coming out with another new goto control during the time of writing this review.

The Pocket Sky also has a T point targeting algorithm but I never use it because it’s more for permanent installations and it needs a number of points. The EM200 moves like silk and makes a beautiful sound when slewing. Some observers describe it as a dentist drill, but it’s a very pure, high pitch sound. I usually avoid meridian flips and view objects in one constellation over the course of each night. If you like jumping all over the sky, a German EQ mount is not for you.

HOW ARE THE VIEWS IN THE FS152?

SPECTACULAR! Star clouds and deep sky views are absolutely stunning and Milky Way vistas are a sight to behold. Star clusters look like powdered sugar. For example, NGC7789 under a dark sky with this telescope is the finest image I’ve seen in any telescope, regardless of aperture. I recall one evening at the 2009 Nightfall star party using the rare 30mm Leitz widefield eyepiece on the Double Cluster with the FS152. It was the best I’ve ever seen it! and a fantastic combination with the telescope. I couldn’t take my eyes off this view, in fact there was a 24″ dob parked right next to it and most of the observers were still gawking at the views in the 6″ Tak even more. You have to remember that everything is relative. If you decide to use a huge telescope, that just means you’re going to be viewing smaller, fainter objects on a louder level. The 6″ Tak produces tailored quality with black, backgrounds, not quantity.

I agree that there are times when aperture is awesome and you need it, however, you have to choose your targets wisely and learn to appreciate the advantages of each instrument. I h

ave a vivid knowledge of the night sky and I love just everything I see, even if it’s just a single faint star.

Another vivid image was the North American nebula using the original 50mm Axiom from Japan (now discontinued) with a UHC filter. If you’ve never seen this, you have no idea what you’re missing. It looks like a picture. You can literally see the Central American region and all the hard outlines around North America. This is one of nature’s greatest spectacles! There is so much to be said for wide field views. Double stars consistently look textbook perfect with tiny airy discs that resemble miniature pin-balls at high magnification under good seeing.

CONCLUSIONS

The Starmaster is a beautiful telescope in almost every regard, but the focuser position is absolutely frustrating to no end. Most planetary observers know that a Starmaster will kill any refractor when the thermals are not an issue, but the fact that the design is not a consistent performer at higher magnification because of it will remain an issue for me and probably for many others who are unaware of the actual problem. Of course this will depend on your observing location.

The Takahashi leaves me with little or nothing to be desired regarding the targets it’s intended for and it’s practically immune to thermals. That in itself, makes it an extremely efficient optical system, even if it is just 6″. It’s a pleasure having both telescopes together. They each have their attributes. The EM200 mount is amazing too and in my opinion, it’s the finest mount in its class. If I had to live with one though, I’d pick the 6″ Takahashi system. It combines the accuracy I need for double stars and the comfort of sitting down compared to the bigger dob and the image quality is out of this world.

Reflectors are still king for planets and still my favorite choice, but there’s a lot more to a reflector than just size. Execution of the design is paramount and the Hybrid would still need to carry some of the same modifications as Ed Grissom’s spectacular planetary Newtonians.  I’ve never seen anything that could rival Grissom’s designs and it’s not as simple as most observers think.

Steady skies,

Daniel Mounsey

aka Dr. D

March 26, 2010

I’ll just get it out in the open now. I have been asked if my views have changed since my first review “Planetary Eyepieces”, so that’s what this review is for. Instead, I’m going to go into a bit more discussion regarding each eyepiece. Here’s what I look for in an eyepiece. I’m not as concerned about other issues as much as I am regarding “on-axis” image quality. Some observers go through a tedious investigation of field of view, pincushion and edge sharpness but I don’t concern myself as much about these issues except for certain circumstances while using faster optical systems or scopes without RA tracking.

One observer I admire regarding eyepiece comparisons is Thomas Back of TMB optical. If you examine the way he reviews eyepieces, you’ll see that he just says it like he see’s it. He doesn’t go into technical detail about the eyepieces, he just looks through them and judges them with absolute simplicity and that’s how I love to hear things. He’s also an experienced purist who knows good optics from bad good optics whether it’s eyepieces or scopes. I admit, there are circumstances where eye relief is an important issue to consider and sometimes it needs to be discussed.

This does not mean technical details are not important, in fact they are very important in some cases because eyepieces behave differently to various observers and various scopes. Mike Hosea and Don Pensack have been very helpful in helping others in this area.

I’ve kept a diary over the years while making comparisons of eyepieces, some recent, some old. I used various instruments from fast Newtonian’s down to F-4.3. I also made comparisons using small and large apochromats. Of all the systems, the apos are the most simple to deal with. All you have to do is set them up and they work and most of all they are practically immune from thermal currents. The best views of planets I’ve ever seen though have come from high quality Newtonians of careful design but refractors are simple.

ISSUES REGARDING EYEPIECE QUALITY

Contrast is usually the underlining issue, however I’ve actually seen some instances where certain eyepieces and barlows in particular just don’t appear to look as crisp. Mike Hosea’s examples of Jupiter here are example of low contrast and high contrast along with sharpness and softness.

Here’s how I define CONTRAST - A striking dissimilarity in color or pigmentation.

Here’s how I define SHARPNESS - Abrupt, clean cut, crisp, well defined, hard.

BARLOWS

There’s been a lot of questions regarding which barlow to buy. As far as I’m concerned and based on the tests I conducted, the Televue 2x and 3x barlow produce the sharpest and highest contrast available. The Vernonscope Dakin barlow is also fantastic and compares to the Televue. Another fantastic barlow is AP’s Barcon. Many observers ask if the Powermate is better. Regardless of how many tests I conduct, the on-axis view of the standard 2x Televue is superior. It’s crisper and has noticeably higher contrast. Some observers are content with their Powermates because they flatten fields and reduce vignetting which are two issues which have no advantage to on-axis views. Crispness and clarity are my biggest concerns. Also, if you are concerned about barlow degrading the image, the differences are not that dramatic. You really need ideal seeing conditions before it becomes noticeable and even then it’s extremely close. I use barlows all the time and own about four different configurations of it which I had made for me.

BINOVIEWERS

If you can ever afford a bino, two eyes are easily better than one and there’s just no comparison. My favorites in order of optical quality are the Baader, then the Televue and finally the Denk.

EYEPIECES DISCUSSED

I’ve left out some eyepieces because there’s quite a few, so if I didn’t cover one you like, then just ask me and I’ll let you know if I’ve tested it. It would take a while to cover them all.

TMB/BURGESS - A friend of mine loaned me a 5MM and 7MM for testing. I’ve heard a lot about these eyepieces in the forums because they’re called super planetary eyepieces. Each one sports 20mm eye relief, making them comfortable to use  for eyeglass wearers. The color rendition is neutral and white. I tested the 5mm and 7mm in the 6″ Takahashi flourite refractor on Saturn on numerous occasions and I personally found the contrast quite lacking in fact out of all the eyepieces in this entire review, the TMB’s were my least favorite. 

UNIVERSITY OPTICS ORTHOS - I love these eyepieces. Even though they are over shadowed by other contenders, I’ve seen instances in certain scopes where I actually like them better than many others. We did the crucial tests with the 4mm and 5 mm. Honestly, unless the seeing conditions and the scope are good, you may be pressed to see a difference but once you know what to look for, it starts to become noticable against high end eyepieces like the Monos. There was an instance where I tested them against some TMB Monos in the TEC 200 apo and noticed it, particularly with the glow around the planets, in fact John who owns the TEC isn’t even that experienced and he noticed it pretty fast. Every time we put the Monos in, the glow was literally cut in half but remember that the TEC is a very high end scope with extreme contrast which will tax any eyepiece to its limits. Dee and I also compared my 5mm UO to her 5mm Mono in the TOA 130 and FC100. When we examined the bands of Jupiter in careful scrutiny, you could see that the picture was a bit more contrasty in the Monos. It was like an extremely subtle cloud over Jupiter in the UO’s but still it wasn’t that far behind. Interestingly the differences were more significant in the 200mm TEC and I believe this happened because of its increased aperture and oil spaced objective. Over all, I would strongly recommend the UO’s to any experienced observer and at $59 a pop, how can you go wrong?

I do have some issues with the 18mm in particular if you wish to barlow them or bino them. Inside the barrel is a beautiful knife edge field stop, but the retaining ring which holds the elements inside is improperly painted with a sort of semi gloss enamel and light tends to get scattered inside this retaining ring. It’s really too bad that the sub contractor who manufactures these eyepieces for UO doesn’t just make some improvements to these eyepieces. From a physical design standpoint regarding the cone tops, they are nicer than any eyepiece in this entire review. I can only assume that their low cost is because they are not fully multi coated, but what an even greater eyepiece they would be if they improved the coatings instead of going to the less comfortable HD design. The images in the UO’s appear neutral and cold and I especially love them on the Moon.

UNIVERSITY OPTICS HD - If you are wondering whether there’s a difference between these and the standard UO’s, there is. Each eyepiece we tested brought the light scatter down a small but noticeable percentage less than the standard UO’s. It got to the point where we could take them in and out and see this difference in background contrast. I also love the 18mm’s for binoviewing in particular, they are very well baffled. I did get the 5mm HD which disappointed me. The contrast was horrible and I sent it back. I was a bit skeptical about it because the FOV was also wider and it looked like a knock off eyepiece. Over all the contrast in the HD’s is a notch up from the standards. Images are cold and are quite similar to what you see in the Tak LE’s. I would recommend these eyepiece to any observer.

TAKAHASHI LE’s - I’ve tested all the LE’s and they are very impressive. While viewing the Moon, the field stops are super clean cut with cold image quality. I ran some very careful tests in the 8″ TEC against the Monos. In comparison, the low contrast planetary color on Saturn’s disc was practically identical. The only difference was the light scatter. There was just a little bit more scatter and less light through-put in the LE’s. The model tested was the 7.5mm and 8mm Mono. Either way, I highly recommend the LE’s and many purists like them. The 24’s and 18’s are great for binoviewing. A great lunar eyepiece. They are a cut above the UO’s in contrast for planets.

ORION ULTRASCOPIC/PARKS GOLD SERIES - The reason these two are together is because they are the same eyepiece with different labels. I tested them all very carefully. I know this review is about high magnification planetary eyepieces, but I still must comment that the 30mm and 35mm models are well designed even though they lack a bit in contrast when compared to others of similar focal length. The 3.8mm, 5mm, 7.5mm and 10mm are not as impressive to me. When comparing them to higher end optics, I noticed they appear to be lacking in contrast. There’s noticeably brighter glow around planets, granted other observers on cloudynights are content with them. The images are cold but I prefer the HD’s. I’ve also compared the 15’s and 20’s in the bino against the Tak LE’s, and the Taks are definitely a cut above in contrast. I also mentioned that I was blown away when Jorge and I tested the 15 Parks against a pair of Televue 16mm type 5 Naglers in the Baader bino and 8″ TMB and both Jorge and I noticed better contrast in the 16’s. We were amazed. It was like a glow that went to almost lights out when the type 5’s went in. In the first review, we didn’t have the 16’s and most of my comments regarding Naglers had to do with the type 2 models as well as the original Nagler 4.8 and 7mm and other various wide fields of different brands and design. All in all, I’d rate the Ultrascopic’s and Parks as good but not great planetary eyepieces based on the observations we’ve conducted. My observing buddy June owns a set of the 10’s and 35’s but he doesn’t care for the 10’s all that much because of the issues regarding contrast once again. We also conducted a comparison of the 35 Ultrascopic’s against a pair of 40mm Televue plossls while viewing H-alpha. Both June and John Risti were present. We were stunned to see considerably finer contrast in the TV’s because we expected the surface contrast and background contrast to be better in the Ultrascopics because of the added magnification and what we got was just the opposite. The Ultrascopic’s revealed a scattered glow of red from the Sun while the TV’s were etched in darkness. All of us were amazed and it was very obvious. I’ll leave it to you guys.

NAGLER T6 - You will notice that Naglers took a back seat in my first review. Well not anymore. The T6 is a noticeable improvement over the earlier design in every way. Light scatter is extremely minimal in fact both Dee and I were surprised to see that there was even less light scatter in the 5mm and 7mm T6 than either the UO or UO HD. The T6’s are wonderful for planets and proved so in my friends 14.5″ Starmaster. Images are a subtle warmth compared to others. Nagler’s are well known for their correction in fast optical systems and considering the fact that they’ve been improved so greatly, I would highly recommend them for any scope, which is contrary to my first review.

PENTAX XW - Now this series of eyepieces is killer! Never in all my years have a seen a wide field perform like one of these. I carefully tested the 3.5mm, 5mm and 7mm against the other eyepieces in this review mentioned above and it cleaned them all out, including the reputable Tak LE 5mm in every manner. The XW represents the pinnacle of the wide field planetary eyepiece arena and was also a cut above the T6 in both surface contrast and light scatter upon careful examination both in the 14.5″ Starmaster and FS102. Image clarity is completely neutral with no visible light scattering or internal reflections which plague lesser eyepieces. Pentax puts out great eyepieces. Their .965 ortho are John Pons favorite planetary eyepiece of all time and he owns just about everything that’s great. Pons is a grand master with 53 years under his belt and uses the most exotic planetary scopes.

TELEVUE 3-6 ZOOM - Around the time this eyepiece was first introduced, I tested it in an 4″ AP Traveler at Charlton Flats. I set it to 4mm and compared it to a 4mm Zeiss Abbe ortho. After changing the eyepieces in an out over and over, I couldn’t help but notice that the Zoom was definitely softer and I concluded that it was like most other zooms. I even examined it carefully to be sure. When I seriously began to question this particular zoom was when I tested another model about two years later. In daylight testing I set it to 5mm and compared it to a Parks 5mm Gold Series plossl using an FS102 early in the morning and I had two other observers with me at the time. I was literally shocked at the differences. The Parks had a faint cloudy cast while the Zoom was etched in perfect contrast and sharpness. This was when I started questioning my first impressions. After this, I still never attempted to test it in the evening until I saw Dee’s. Dee and I used the Zoom set at 5mm along with a 5mm Mono and a 5mm ortho on two different occasions. The second occasion was Jupiter. In terms of the actual planetary color pigmentation on Jupiter and as shocking as this may sound to some, I liked the Zoom more than the Mono. It was just a bit warmer but there was still a bit more back ground contrast in the Mono. The UO came in 3rd place but understand that I’m only referring to the colors on Jupiter. Even Dee noticed it and agreed regarding the colors on Jupiter. After the first time I tested Dee’s I was lucky enough to acquire the original unit from the original owner and sure enough after careful testing against another demo unit I acquired from work, the old one was not the same. I would have to say that thanks to Dee, my thoughts regarding this eyepiece have changed for the better. There’s also a nice knife edge baffle at the end of the barrel. Great eyepiece, which is contrary to my original impressions. Sorry Al. I actually discussed it with him at RTMC.

EDMUND RKE - If there was ever an eyepiece that really surprised me, it was the RKE. Too bad they were not so respected over the years since they’ve been around as long as most veteran observers can even remember. Some of the finest planetary images I’ve ever seen have been through the RKE’s and they rank as one of my favorite planetary series of all time. Sadly, right around the time the original planetary eyepiece review, Edmund was going through some transitions and at least during some of my experiences and others, the quality just didn’t seem the same in some of them but not all were like this. Carlos Hernandez, who is one of the most highly skilled planetary observers in the world became curious about them after the planetary eyepiece review was posted. After receiving them, we had communicated with each other regarding the quality. I recall him mentioning that the field stops in the barrels had some burrs around them. This doesn’t effect optical quality but it does create doubt regarding quality control. In some of the later models I noticed this as well. Another issue was when my observing buddy John Risti acquired a set of the 28’s for his bino and sadly in one of them had polishing streaks in the actual glass as if it hadn’t been fully polished. One clue I noticed in some of the later models were the black barrels, which appeared to be painted instead of anodized on some units. Most of the earlier models were anodized. I can not state that this necessarily determines the good ones from the not so good ones, but it helps. Some observers absolutely love them, myself included, but some don’t. Never the less, the images are cold and they’re awesome for the Moon, Saturn and Mars. Unfortunately the 8mm has a reversed volcano top, which makes it a bit less inviting to look through, but if you can get a set of good ones, they will not disappoint you. I recall a number of occasions while comparing them to others at Charlton and seeing them outperform some of the best eyepieces in this review in the contrast department and they can be very crisp. Strongly recommended, especially if you can find some earlier models and the 15mm 21.5mm and 28mm are wonderful in a bino. You’ll probably either like’m or dislike’m.

PENTAX XO - When Pentax first introduced this eyepiece I have to admit I was less than excited. How wrong I was! It is so sad that Pentax does not have this eyepiece in anything other then a 2.5mm and a 5mm. If you’ve ever wondered what they’re like, I’m here to tell you that they will compete with any planetary eyepiece in the world today. The contrast is absolutely stunning, in fact the only difference I could possibly detect between it and the TMB super mono was light through-put and even that was barely noticeable. Other than this, the light scatter and contrast was nothing short of sensational, making it one of the finest planetary eyepieces of all time IMO. Images clarity is completely neutral and crystal clear. Expensive but about as good as it gets. Strongly recommended. Images cold

TELVUE RADIAN - Sadly, I’ve just not been able to get into this eyepiece dispite the fact that I’ve tested numerous models. Perhaps it’s the internal lens design. What I noticed in two different 12mm units were internal reflections. This also occurred while testing a 5mm unit as well. This is not to say the Radians are bad. Some observers have had wonderful experiences with them on planets however for me, I just don’t get that impression. I’ll leave it to you.

CLAVE OF PARIS - I’ve never seen an eyepiece as warm as these, in fact they’re warmer than any Televue eyepiece I’ve ever seen regardless of the model. They exhibit a unique coffee tone which gives Jupiter a gorgeous richness in the bands. Sadly they are rare and hard to find but will sell on the used market for about $200 to $250 used. If you’re lucky enough to find one you like, don’t hesitate, they wont disappoint. Very similar to Televue’s plossl however I still like the crispness of the TV’s. I don’t like it as much on the Moon, Saturn or Mars but Jupiter, it’s wonderful. Pons has every one, all the way up to the 2″ 70mm which many of you have probably never even heard of. Images extremely warm.

BRANDON - When I first reviewed this eyepiece I was hard on it because I was hoping to get a bit more warmth out of the image for Jupiter. What I’m about to share with you may sound surprising but this occurred at Charlton Flats where we conduct planetary observations. My friend Jorge and I were observing Saturn with his 8″ TMB and his then new Baader binoviewer. We tested various eyepieces that night. The 12.5mm UO’s, 15mm Parks Gold Series, 16mm Nagler T5’s and a set of 16mm Brandons. To my amazement and Jorge’s, we were actually shocked to see that the Nagler T5 16’s clearly beat out both the UO and Parks GS. We could easily see less light scatter in the 16mm T5 Nagler’s, then when we popped in the Brandon’s it was all over. The image was completely etched in tack sharp contrast and clearly out performed these other sets of eyepieces. Like I said before, I was hard on the Brandon’s, but they are highly regarded eyepieces. Pons loaned me two complete sets in brass for testing. Images are completely white and neutral and are probably the finest eyepieces for solar wedges. If you’ve never seen sun spots in a solar wedge, trust me, you don’t know what you’re missing. Glass and Mylar filters are not even close in comparison to a solar white light wedge! The Brandons are highly recommended and are stunning on the Moon.

TMB MONO VS. TV PLOSSL - The TMB’s seem to have become the standard by which others are judged. Look at me, I used them to judge other eyepieces as well. Since many observers feel this way, I’m here to share my own input. My main instrument of choice was the TEC 200 despite the fact that I’ve tested all these eyepieces in other apochromats. The TEC exhibits some slight under correction but this in no way has hindered the image. Seeing slight differences in the star test is completely normal and I love the TEC’s contrast since the elements are oil spaced. I’ve tested various focal lengths in the Mono series but the most interesting test of all occurred while using an 8mm TV against a 10mm Mono. Now I know many of you are thinking this is a bit odd because of the difference in focal lengths but I had reasons for conducting the most crucial test this way.

Several years ago I used nothing but an FS102 for planetary observations. I used this scope for a full five years and viewed many many nights with it. My observing buddy had and FS128 which he had already been using for about 8 years. My 4″ was a small scope but I learned a lot from using it. What many observers forget about while viewing planets is that as you increase magnification, you are decreasing planetary color contrast. It’s like taking a piece of pink chewing gum and stretching it out. The more you stretch it, the whiter it get because you are taking that same information and spreading it out. This same effect happens on planets as you increase magnification. In order for me to get the same color contrast as my friend was getting in his 5″ Tak, I would have to decrease my magnification, but the price I would have to pay is having to observe a smaller planetary disc.

In the TEC we used an AP Barcon at 1.7x according to AP’s stats. This would give the 10mm Mono 317x on Jupiter while the 8mm TV would propel the TEC to 396x. This is about 40x per inch for the Mono and 50x per inch for the TV plossl. These magnifications are a bit extreme under most circumstances but necessary for this comparison. I used eagle eyed June Trajano to help judge the images on this incredible night.

I observed with the Mono first at lower magnification. Jupiter’s bands revealed a gorgeous wealth of detail and I could actually discern little white ovals within the polar hoods. No Red Spot was present at this time but I could discern subtle color shadings. The browns and beige colors were accurately represented IMO.

I then popped in the TV 8mm and was dumbfounded. I didn’t say a word and allowed June to compare the two before I spoke. After watching him switch back and forth I finally said, Well? The first words out of his mouth were, I like the Televue. You know what? I concluded the exact same thing.

Some purists may be surprised at my conclusion but just because an eyepiece gives you the most accurate representation of planetary colors does not mean they look their most pronounced. I took an image of Jupiter and held a B+W coffee filter over it granted I don’t like filters and asked Dee which image she liked. She noticed what I was talking about pretty fast. The TV has a slight coffee tint, but it’s just enough to give it that edge in color contrast over the Mono and what’s even more incredible is that it did it at higher magnification. Remember the chewing gum? We all see colors in different ways and some purists prefer the Monos and that’s OK, we all have opinions. My opinions are based on very careful visual tests and unlike most purists who are obsessed with white, I’m not. I like a little warmth or depth in the image. In other words a more rich and creamy appearance. I should also say that the while comparing the 8mm in both brands, the Televue gave up absolutely nothing to the Mono in background contrast or light scatter characteristics. This whole issue with me has to do with color pigmentation. The Mono does have more noticeable light through-put though.

The Televue is not without it’s faults. Some vignette on their own, particularaly in barlows but for axial performance, it doesn’t matter. I also don’t care for them on the Moon. I do find it sad that Al Nagler doesn’t have the TV plossl produced in various 1mm focal length differences starting at 4mm but regardless, the Televue plossl represents the pinnacle of the planetary eyepiece world to me, thus making them my favorite planetary eyepieces of all time.