January 26, 2016: 35-Year-End Review, Part 2 – Scopes and Eyepieces

Continuing with my review of the ch-ch-changes (we’ll miss you, Starman!) I’ve experienced in astronomy over the past 35 years, we move on to the telescope and eyepiece revolutions.   As far as we knew, the largest “portable” telescopes back then were the C14s, the orange tube SCTs.  Oh, there were ads in Sky & Telescope for those ridiculously-sized Cave Astrola howitzers, er, Newts, of 16 inches or so, but come on.  They looked like you’d need a crane or at least a forklift to move around.  And the nerds in weird lab coats using them in the ads didn’t help their image much.  No, to us as teenagers, even though the C14s were hugely expensive, those were the largest we could ever hope to have.  

Around 1982, when we finally did learn about the existence of our local astronomy club, and went to a star party on Jones Beach for a lunar eclipse, we found out that we were on the cutting edge in terms of aperture with my 8-inch Newt and my friend’s 8-inch SCT.  There weren’t any scopes larger than ours there.

John Dobson had started the dobsonian revolution in the 70s when he put a Newtonian on a simple to build, easy to use, altitude/azimuth mount.  As commercially-made dobs became widely available in the mid-80s, humble Newtonian reflectors have slowly but surely taken over much of the hobby.  Where an 8-inch Newt was pretty big 30-odd years ago, an 8-inch dob, at just $399, has now become the default recommendation to beginners entering the hobby (which I take issue with, but that’s not a discussion for this post), under the thought that the best telescope to get always has the largest aperture you can afford.  Not only is the dob cheaper in absolute terms than the $489 I spent on the Meade 826 in 1979, but when you also consider inflation, that $489 for the 826 then is more like $1600 now, four times today’s cost.  That truly is a revolution.  Cheap aperture for the masses.

But another area of astronomy has expanded as well, as people succumb to aperture fever: premium telescopes.  Back then, there was only one premium telescope:  the Questar, a little 3.5-inch jewel of a scope, the Rolls-Royce of scopes.  This thing was absolutely gorgeous and utterly drool-worthy; almost more a work of art than an actual scope.  35 years later, they still are.  At only 3.5 inches of aperture, although it was stunning, it just wasn’t something to aspire to, astronomically speaking.  Yeah, sure, I lusted after one, but only because it was so damned pretty!  Not because I thought it could best my scope.  You often saw the Questar used in movies to imply that it’s owner was wealthy.  I just saw it the other day in 1984’s Body Double, where a peeping Tom uses one to watch Melanie Griffith do, ahem, what she calls a “self-help routine.”

Back in the day, I barely even knew what kind of design the Questar was.  In the meantime, of course, I’ve learned that it’s a Mak, and an exquisite one, at that.  As Questar was the only Mak out there in the marketplace, I had never hoped to ever be able to afford a Mak.  And now look!  I’ve got one of my very own.  Dreams can come true.  

Now we have all sorts of premium telescopes, specialty scopes, like Obsession, Discovery, New Moon, Teeter – dobs all, every single one of them.  12 inches, 16 inches, 20 inches, 24 inches (!!!), and more.  Oh, there are still those 14-inch and now even 16-inch SCTs from Celestron and Meade, mounted on ginormous piers or forks, and costing $10,000, $15,000, and even $20,000.  But the dobs, with their longer truss tubes, are so much larger than that, even at the same aperture.   These premium dobs start at $2000 and go up to $10,000 and more for the largest ones.  But of course, with all of these Newtonians and SCTs comes my dreaded enemy:  collimation.

Where there used to be no apos at all, now there are 5 and 6-inch ones – William Optics, Skywatcher, Explore Scientific, and of course TeleVue, too.  All starting at around $5000 and going up into the stratosphere.  There was even a seven-incher at NEAF last year.  This is the rarefied air – and empty wallets – of AP.  

Beyond the enormous expansion of apertures that has taken place due to the dob revolution, to my mind, the biggest change in equipment in the past 35 years has been in the area of eyepieces.  Back in the day, you could get a gigantic scope – a 14-incher, a 16-incher.  It’s just that now you can just get them much more inexpensively.  But the eyepieces – how you actually view the sky – have changed and improved immensely in 35 years.  

Then, the scopes we bought came with what Meade called (and still calls) Modified Achromatic EPs; otherwise known to the rest of the astronomy world as Kellners.  These EPs work better in slower focal ratio scopes, so in a 6″ f/8 newt, or an 8″ f/10 SCT, these worked fine.  I can’t recall any complaints I may have had about how they worked in my faster 8″ f/6 Newt, but maybe that was because I just didn’t know any better.  As I’ve mentioned before in this blog, the stock 9mm Kellner that came with my Mak works just great with its slow f/12 focal ratio.

As Silent Bob would never say, what we didn’t know about eyepieces back then, we could just about squeeze into the Grand Canyon.  We didn’t know about field stops, eye relief, coated, multi-coated, fully coated, or fully multi-coated.  I doubt that the eyepieces were even marked that way, let alone what coatings they had or didn’t have.  Nowadays, of course, almost every EP is fully multi-coated, and those that are not – like some orthos – have some valid optical reasons apart from cheapness as to why they are not.

Not counting Huygenian and Ramsden EPs – which are the cheap, awful, terrible narrow-field EPs that come with department store scopes – as far as we knew back then, there were only three types of EPs:  1) three-element modified achromatics (Kellners); 2) four-element orthoscopics; and 3) five-element Erfles.  That was it.  Two-inch EPs?  Never heard of them.  As far as we knew, they did not exist.

Even then we knew then that orthos were supposed to be the thing for high-powered planetary and lunar observing, and were supposed to be an improvement over our modified achromatics.  Neither of us actually knew a thing about those 65-degree widefield Erfles, or why we might want such a wide apparent field of view anyway. 

Little did we know at the time, because neither of us ever bought one, but Erfles are supposed to only be really useful in slower focal ratio scopes – like my friend’s f/10 SCT back then, or my current f/12 Mak.  With faster newts, they are not as sharp at the edge, and get progressively worse the faster the focal ratio becomes.  My understanding is that Erfles live on today in the five-element Orion Expanse line of EPs, and its various -and much less expensive – clones.

At some point when I was a teenager, I decided to take the plunge, and bought a 4mm orthoscopic, which gave me 300x in my 8-inch Newt.  This actually wasn’t too much power for the optics of the scope.  But it was probably too much power for the combination of my seeing conditions and my probable lack of collimation, neither of which, again, we knew anything about.  This much magnification was really only useful on the moon.

Meanwhile, around the same time, we learned of a fourth type of EP, a “brand new” type.  My observing buddy bought one of these newfangled eyepieces, a Plossl, for his 8-inch SCT.  It was a revelation to us.  Thinking back, I believe it was a 20mm, which in his 2000mm focal length scope would give 100x.  It certainly was an improvement over the Kellners, both in terms of sharpness, and the beautifully, ahem, “wide” field of view – a nice improvement from about 43 degrees to 52 degrees.  My jaw just about dropped open the first time I had a look.

Plossls, the Holy Grail 35 years ago, aren’t even special now.  At all.  Most telescopes beyond the lowly department store kind now come with Plossls as their base, standard, stock equipment.   However, I believe that they continue to be great, well-balanced, all-round eyepieces, sharp to the edge.

Unbeknownst to us, it was literally right at this time in the early 80s that Al Nagler began the widefield revolution.  Al’s company, TeleVue, began putting out their wonderful Plossls, to be followed shortly thereafter with the 82-degree Nagler line of EPs, and then a 65-degree Widefield line of EPs, which were modified within a few years to become the 68-degree Panoptics.  Within a few years, as the popularity of TeleVue EPs grew, the other big vendors, first Meade, and then others, essentially cloned these designs to create their own versions of these widefield EPs.

Currently, there are any number of different types and AFOVs on EPs.  Essentially, if you want a particular degree apparent field of view, it’s out there for you, as long as you can afford it.  As the fields of view get wider (above 70 degrees), the prices start going up into the stratosphere.  There’s 52 (any old Plossl), 58 (Zhumell Z Planetary – BST 58 UWA Planetary), 60 (Celestron’s X-Cel LX – Meade 5000 HD-60 – Astrotech Paradigm – Agena Starguider), 62 (TeleVue DeLite), 66 (Orion Expanse – Agena Enhanced Wide Angle, and other clones), 68 (numerous, including Explore Scientific 68, TeleVue Panoptic, Baader Hyperion, Celestron Ultima Duo, and many others), 70 (Agena SWA, Bresser 70), 72 (TeleVue Delos, Baader Hyperion Aspheric, William Optics SWAN), 76 (Baader Morpheus), 82 (numerous, including Explore Scientific 82, TeleVue Nagler, Meade Series 5000 Ultra Wide Angle, Celestron Luminos, William Optics UWAN), 90 (Takahashi UW), 100 (TeleVue Ethos, Explore Scientific 100, Meade Mega Wide Angle), 110 (TeleVue Ethos, William Optics XWA), and even 120-degree AFOVs (Explore Scientific 120).  You pick.  And of course, you pay – through the nose, in some cases.  

Barlows have also changed and improved enormously.  I had a Barlow back in the day.  I could not bring it to focus properly.  I’m not sure if I didn’t have enough in-travel or out-travel in my focus tube, but I just couldn’t get it to work.  Then again, I might have been using it on a 4mm ortho to go from 300x to 600x, so that might explain why it didn’t work – that’s too much power for anything.  But thinking about it some more, I think I was using it on my 9mm “modified achromatic” (i.e., Kellner) to go from 133x to 267x, which would have been a reasonable thing to do.  

The problem, of course, was that there was simply no one to ask.  Yes, there was as astronomy club on Long Island, where we grew up, but we were just kids – who would help us?  The internet wasn’t even a gleam in Al Gore’s eye in the late 70s and early 80s.  There was no readily available source of information to tell us anything beyond what we might read in Sky & Telescope.  

Back then, Barlows simply were not built up to the quality that they are now.  I don’t know if it’s because they had only one lens element, or what, but they were definitely junk back then.  Unfortunately, these junky Barlows survive today in the Barlows that come with most department store scopes.  Now, a good quality, two-element, achromatic Barlow can be had for just $30-40 or so, and a three-element apochromatic Barlow is available for not too much more.  They’re now available in 2x, 2.25x, 2.5x, 3x, and 5x flavors; the higher multipliers are useful for doing AP.  

Now I have a 3-element, Japanese-made, long-format Barlow, an Orion Ultrascopic.  This was one of the many accessories that came with my ST-80 when I bought it, and it gets lots of use on the moon and planets.  I don’t know if it “vanishes” out of the optical train like some people say that the TeleVue Barlows do, but it takes my 12.5 ortho from 123x to 246x, and still looks good doing it, if the seeing can support it.  I’m happy with it.  

There weren’t any binoviewers back in Pete Rose’s time.  Nor were there any two-inch EPs.  The only finders were straight-through little refractors – no red dot finders, or green laser pointers, or RACI finders with interchangeable EPs to be had, thank you very much.  There were light-pollution filters available back in the day.  But these were expensive, and we doubted their ability.  I, for one, scoffed at the claim that a simple piece of glass could reduce the glow from streetlights.  “Why, how could that even be possible?  Next you’ll be telling me that those X-ray specs actually work, too!  Just exactly what sort of deviltry is this?”

Next time:  35-Year-End Review, Part 3

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