Tele
Vue Ranger Review
Tele Vue’s classic ‘Ranger’ small
refractor from the 1990s uses the same optics as the astronomy-oriented Pronto,
in a smaller and lighter package more suited to terrestrial use (but perfectly
good for astro’ too). It was widely adopted by birders and Tele Vue even made a
stay-on case for it.
The Ranger employed a unique sliding
bar, ringless mount and a drawtube/helical focuser combination that was simple
to use and helped keep weight down, which many loved and some didn’t. The
Ranger was eventually discontinued in favour of the smaller and more
sophisticated full-apochromat TV-60, but the newer scope continued the Ranger’s
mount and focuser.
Between them, the Pronto and Ranger
introduced numerous people to astronomy in the Nineties and re-booted the interests
of many others (self and Ed’ Ting included). I owned the Pronto, but I thought
that twenty years on it was time I took a fresh look at the Ranger to see how
it stacks up in a modern world of cheap Chinese small refractors.
At
A Glance
|
Telescope |
Tele Vue
Ranger |
|
Aperture |
70mm |
|
Focal
Length |
480mm |
|
Focal
Ratio |
F6.8 |
|
Length |
40cm |
|
Weight |
1.5 Kg
(incl dovetail mount rail) |
Data from TeleVue/my own measurements.
Design
and Build
Like the Pronto, the Ranger was proudly
made in America and has an artisanal feel to it mostly gone from the market
now. This was an item produced in reasonable volume, but retains an ATM feel –
the way a really skilled engineer might make a little scope for himself. It’s
something I think people increasingly value in Tele Vue products.
Unlike the TV-60 which is unique among
TV’s range, past and present, the Ranger has features that connect it with
other Tele Vue scopes. The tube has the familiar ivory pebble powder coat; the
combined cell and hood are a miniature of the Renaissance’s; the metal parts
are finished in contrasting glossy black-anodising (long replaced with satin in
newer TVs) just like my TV-76’s.
Ranger with its contemporary small APO
– Takahashi’s FC-60. Tak’ is longer; they weigh the same.
Optics
The Ranger
shares its 70mm F6.8 (480mm F.L.) doublet lens with the Pronto. The spec says
it uses ED glass, but a famous telescope designer has said it was a cheap ED
that delivered only modest benefits in false colour correction.
In the past
I’ve agreed and said that the Ranger and Pronto are achromats. If so, then they
perform better than a 70mm F6.8 achromat – more like one at F8 to F10. Still,
the Ranger and Pronto are not apochromats like the replacement TV-76 and TV-60.
We’ll settle with describing them as a semi-apo towards the achromat end of the
scale.
Interestingly,
the Ranger lens has no visible foil spacers. That would usually mean a
lower-performing cemented design, but investigation with a laser reveals a
larger air-gap – a technique often used to deliver improved correction (for
false colour, but potentially field curvature too).
Tube
The TV-60
that directly replaced the Ranger has an all-CNC tapered tube with integrated
sliding dew-shield. The Ranger was much more conventional. It has a fairly long
aluminium body, coated in pebble ivory like almost every other Tele Vue all the
way up to the NP-127 (though many birders chose the optional green pebble coat,
whilst some opted for living-room-classy brass).
Although the
Ranger is about five inches longer than the TV-60, it is virtually the same
weight: 1.5 Kg including the sliding dovetail. It’s also exactly the same
weight as Takahashi’s FS-60C including its clamshell. This low weight gives the
Ranger a significant usability advantage compared with the optically-identical
but twice-as-heavy Pronto.
The Ranger’s
dew-shield is short and fixed and combines with the lens cell. The lens is
fixed into the tube with bolts and isn’t collimatable. The focuser threads
neatly on. Unlike a Pronto (and many other Tele Vues) which has a screw-in
metal cap that takes ages and screeches, the plastic lens cap just clicks into
place like a camera’s, even though the hood is internally threaded.
Internally,
like all Tele Vues, the Ranger has no baffles. Instead it’s lined with flocking
material that looks like coarse sandpaper painted flat black.
Focuser
Whilst the
Pronto had a single-speed r&p focuser with the famous ‘mag’ wheels, the
Ranger uses a more unusual system with a drawtube for coarse focus and a helical
for fine. The biggest downside is that it doesn’t allow for 2” eyepieces,
unlike the Pronto’s.
Some people
didn’t like this focusing system that carries on into the TV-60 today. I’m not
one of them. For one thing it gives the Ranger loads of focus travel – so much
that astrophotography is possible with no extra extensions. For another, you
effectively get a fine focuser which the Pronto didn’t have unless you paid for
an aftermarket unit and managed to fit it without losing a shim or
cross-threading a screw (as many did).
The drawtube
and helical unit are simple but very robust and well-engineered. They work well
with no slop, but after a few years the grease goes hard and you need to
disassemble the helical part and clean then re-grease it. I explain how here in
a separate article elsewhere on this site.
The focuser
drawtube has machined-in ridges and is painted matte black to kill internal
reflections.
Focuser with
drawtube retracted and extended.
Mounting
The Ranger,
like the later TV-60, avoids the Pronto’s heavy clamshell in favour of a
sliding bar to which the tube fixes with a clamp. It’s a system that makes the
Ranger very easy to balance and saves weight
The sliding
bar has the usual TV pair of ¼-20 threads on the bottom that fits Tele Vue’s
Panoramic mount and a single ¼-20 thread for a substantial photo head. Or you
can affix TV’s own Vixen dovetail for Vixen and Skywatcher mounts, which I did
to mount the Ranger on a Vixen SX2 for testing.
TV-60 experience
suggests the Ranger will work much better on a Tele Vue Panoramic mount than
their heavier scopes do.
I mounted
the Ranger on a basic Manfrotto fluid head atop one of Berlebach’s cheapest and
lightest ash tripods. The result was a one-hand grab-n-go outfit that worked
really well. Having adjusted the sliding bar to the perfect balance point, I
was able to slacken the fluid head to get really smooth panning. I found it
stable up to quite high powers and ideal for quick looks at the Moon from around
my drive and garden. This is where the Ranger beats the Pronto, which was too
heavy for the same head.
Incidentally,
Tele Vue once made a hardwood table mount for the Ranger called the ‘Executive’
mount. It’s a rare item I’d love to own.
Ranger on Vixen
mount with TV-Vixen dovetail plate attached to its sliding bar.
Ranger
mounted on a lightweight fluid photo head.
Accessories
Various
accessories were available for the Ranger, including:
·
A padded and
semi-waterproof stay-on bag
·
A rubber
lens shield that screwed into the threaded lens hood
·
The Quick
Point red-dot-finder that attaches via a small dovetail adapter (which itself
screws into a slot atop the Ranger’s visual back)
·
A Vixen
mount dovetail adapter that screws into the 1/4-20 threads on the Ranger’s
mount bar
The Ranger
was supplied with a 20mm Plossl; other focal lengths are obvious accessories.
Ranger in
its stay-on case, ready for birding!
Ranger makes
a very decent terrestrial telephoto lens.
In
Use – Daytime
True to its
multi-use spec’, the Ranger makes an excellent daytime spotter or birding
scope. With a mirror diagonal, it may deliver a left-to-right reversed view,
but sharpness and resolution are at levels few prismatic scopes can deliver.
Colours are vibrant, detail excellent.
Crimson
Whitethorn berries on branches 50m away have an almost hyper-real level of
clarity and detail at low power. The same is true of autumn leaves on the beach
tree opposite, or waders out on the bay sands.
At 32x, I
watch a crow stalking about in the fields opposite with an extreme clarity no
binoculars, no prismatic scope, can ever give – tiny droplets of water gleaming
amid the feathers. This is why birders once valued the Ranger and Pronto so
highly.
With
flat-field eyepieces like Naglers, the view is undistorted right to the field
stop and even a Tele Vue Plossl deliver a very sharp view across almost the
whole field.
However, the
Ranger does have limitations. Watching a Jackdaw sitting on a branch partially
silhouetted against silvery bay waters, at 32x with a 15mm Panoptic, the black
feathers are rimmed with a touch of purple and green. My usual test of branches
viewed against the sky at ~100x yields a wash of violet in focus.
It’s the same
with anything that has very high contrast. But I wouldn’t want you to think
this is a deal-breaker; for most things at modest powers it is not and the
Ranger delivers a great daytime view. But it’s worth noting that the Ranger
shows much more false colour than a TV-60.
So, in bright
conditions the Ranger is best at powers not much over 50x. Beyond that, the
view is still sharp and detailed, but now bright objects are creating quite a
lot of purple false colour that is starting to wash-out contrast.
Another issue
is that short lens hood: skylight washes onto the lens and washes out the view.
Mine came with the rubber lens hood accessory and that’s why.
The Ranger
makes an excellent telephoto lens during the day. The focuser drawtube has so
much travel you don’t need an extension tube for targets further than about 10m,
making photography very easy with a T-adapter and a 1.25” nose-piece. Results
are good, but again high contrast areas do show more purple fringing than
through a true apochromat.
In
Use – Astrophotography
Despite the
1.25”-only focuser, the Ranger makes an adequate casual astrograph. Images are
quite flat across an APS-C sensor, stars only distorting at the edges.
Likewise, illumination only drops off in the corners.
Now, though,
that semi-APO lens shows its true colours, literally, because white stars show
quite a lot of violet bloat. The Pleiades, for example, are much more colourful
than they should be. But for galaxies, brighter nebulae and clusters, the
Ranger’s sharp optics and reasonably fast f-ratio produce good results. As
usual the subs below are straight from the camera.
For its
modest image scale, the Ranger takes a good sharp image of the Moon.
M31: Fuji
XM-1 APS-C: 85s at ISO 3200.
M45: Fuji
XM-1 APS-C: 42s at ISO 3200.
Cropped
Ranger image of the Moon with slightly boosted contrast.
In
Use – The Night Sky
General
Observing Notes
The thing
that really hit me using the Ranger, after reviewing several
clever-but-complicated Borgs and Takahashis in the same size range, was just
how wonderfully simple and fun it is to observe with. No messing with
interchangeable visual backs, yet there is loads of focus travel for any
eyepiece and getting a good balance is super easy – just slacken the clamp
thumb screw and move the tube on the bar.
The Ranger’s
short length means the eyepiece is always in a convenient position and its
light weight makes handling easy too. The short focal length means you mostly
don’t need a finder.
The Ranger
only takes 1.25” eyepieces, but this really isn’t much of a disadvantage
because a 32mm Plossl or 24mm Panoptic give 3.2° of true field, which is more than enough for most
things.
Cool
Down
A light
aluminium body and simple doublet lens means the Ranger cools super fast and
delivers good views straight from a warm house.
Star
Test
All Tele
Vues are good optically, but oddly this Ranger has a perfect star test with
identical Fresnel rings that zing out either side of focus. There is just a
little violet out of focus in the star test to confirm this isn’t a
full-apochromat.
The
Moon
Just after
full, with Mare Criseum starting to be picked out with terminator shadow, the
Moon through the Ranger surprised me. A cold hard ball full of detail was much
as I expected at 32x. At 96x with a 5mm Nagler it was still a great view,
albeit with a purple fringe off the limb. At 137x with a 3.5mm Nagler, the view
was still good. Yes, the purple was now bright and obvious, but it wasn’t
washing out the detail and everything stayed sharp and contrasty. Short focus
achromats don’t do that, Tele Vue’s own Renaissance included, washing a lot
more violet across the Moon’s craters at powers over 100x.
Back at the
Moon, I enjoyed the embayments and cliffs and craterlets around Mare Criseum,
bright Proclus with its odd shape. Nearer the limb, I could make out Hummocks
on the floor of Gauss, the central peak in Hahn. I found the Messier twins and
their bright rays. Next night, the strange straight rille like a clock hand in
Petavius was easily resolved in poor seeing.
One frosty
November Monday morning of excellent (8-9) seeing, I got up early and looked
out on a last quarter Moon, high in the sky just off the meridian, with
Albategnius on the terminator. With a 3.5mm Nagler giving 137x, I could make
out the craterlets like a string of beads along Rima Hyginus and Rima Ariadaeus
disappearing into the lunar night.
The view was
sharp and full of detail: running down the terminator, I enjoyed Mons Piton
shining alone in Mare Imbrium near the ‘ring wall’ of Archimedes, the sharp
peaks of the Apennines, the slumped walls of Tycho in extraordinary detail.
Clavius and its arc of craters.
On another
night, a bright gibbous Moon did show quite a lot of false colour at 137x with
a 3.5mm Nagler, though, where an FS-60Q did not.
Increasing
magnification to 192x with 2.5mm Nagler, the view stayed surprisingly sharp.
But now a wash of pale lilac started just back from the dark limb, spoiling the
view and reducing contrast. In this respect, the Ranger outperformed the TV
Genesis, but the Takahashi fluorite doublets alongside could take higher powers
in the excellent seeing and without that wash of false colour.
Overall,
and despite the purple rinse at high power, the Ranger gave a very satisfying
view of the Moon.
Mars
I caught
Mars low in the dawn sky at the beginning of an opposition year when it was
quite bright but just 3.8” in size. The Ranger showed a nice little orange disc
with just a trace of false colour at 96x with a 5mm Nagler.
Venus
At 96x with a 5mm Nagler, Venus at Magnitude -4 in a bright dusk sky
showed lots of violet and purple either side of focus.
In focus, the 14 arcsec gibbous disk was crisply defined, but had a
broad ring of muted purple around it. Interestingly, compared with a Takahashi
FS-60C, the Ranger generated much more false colour but defined the bright
planet more clearly.
Deep
Sky
Early before
dawn one frosty November morning, Gemini, Orion, Leo and Auriga hung in front
of my balcony twinkling coldly. I set the Ranger out and went deep sky
observing – honestly more fun than I’ve had with a scope since I can remember.
Swapping
between just three (of TV’s own) eyepieces were all I needed – a 32mm Plossl
(my most used eyepiece for 20 years), a period 15mm Panoptic and a 5mm Nagler
T6 giving 15x, 32x and 96x respectively. But even just the standard 20mm
Plossl, included with the Ranger new, would give great deep sky views at 24x.
The Ranger’s
optics give a very flat field with the perfect lens squashing all the light
into the tiniest stars across the field to give strong star colours. For deep
sky, false colour just doesn’t intrude visually, even on brighter O-A stars.
I flitted
between Orion’s sword, the diamond Pleiades, brilliant but faintly misty,
Auriga’s clusters, the Double Cluster in Perseus. I split Castor and enjoyed
some simply beautiful star fields. Everything looked gorgeous, more so than in
a 60mm because the Ranger is grabbing 36% more starlight.
With Rigel
low in mediocre seeing and strong moonlight, I was still able to pull Rigel B
out of the glare, better than in an FS-60Q alongside. On another night, I just
about split the Double Double in terrible seeing too.
I had a good
view of the Ring Nebula, it’s shape easy to pick out with averted vision
through a Nagler 7mm at 69x – much better than the FC-60, with a third less
light gathering aperture and that uncoated fluorite element. Similarly,
globular cluster M15 was easier to pick out from Moonlight through the Ranger’s
70mm ED lens than the FC-60’s 60mm fluorite one.
Here, I
felt, I could really channel Al Nagler: astronomy at its simplest and most
rewarding. The Ranger is a very nice deep sky tool.
Tele Vue
Ranger vs TV-60
TV-60 and
Ranger – photographed in January almost exactly a decade apart.
This is a
most interesting comparison for me, because Tele Vue replaced the Ranger with
the TV-60 and you would expect that the TV-60 would be better all round, but as
I’ve hinted that’s not quite true.
The TV-60 is
certainly smaller than the Ranger, but they weigh the same. The TV-60 has
near-perfect apochromatic optics, whilst the Ranger is at best a semi-apo. But
for astronomy the Ranger generally takes high powers just as well, albeit with
more false colour that spoils the view of the Moon a bit above 100x.
The TV-60’s
lack of false colour does allow higher powers during the day, but 36% greater
light gathering area and 13% higher resolution generally means the Ranger performs
rather better at
night.
An extra
10mm means a lot for this size of telescope and the Ranger gives significantly
better views of DSOs and potentially resolves more detail on the Moon (though
in a less perfect manner).
The clincher
for me is that I prefer the classic white tube of the Ranger. It costs a lot
less used, too.
Unless you
really need the tiny size of the TV-60, or will use it mainly for the Moon, I’d
recommend the Ranger.
Summary
Big aperture; massive goto mount; quadruplet fluorite; 100° monster eyepieces; huge rotatable focuser: the Ranger is a reminder
you really don’t need those things to enjoy astronomy. In contrast, the Ranger
is gloriously simple, relaxing to use and extremely versatile; it was
thoughtfully designed that way.
The Ranger has beautifully sharp optics and very high quality
mechanicals. It’s likely to be rugged too (this one is still perfect 20 years
on). At current prices it’s an absolute bargain – much cheaper than a truly
just-an-achromat Borg 60mm, for example.
However, despite the quality of its optical figure, the Ranger is, if
not an achromat, a very modestly corrected semi-apo. Still, this seems less of
an issue for astronomy than for terrestrial use – it will happily take high
powers on the Moon which short-F achromats won’t. Even during the day, for
birding or nature viewing, spotting-scope magnifications (i.e. up to 50x) give
perfect views.
So, I would be very happy with the Ranger as my only quick-look and
casual travel scope, I just wish TV had put the TV-76’s apochromatic optics in
the Ranger instead or turning it into a more limited 60mm format for the TV-60.
But the bottom line is that I loved the Ranger for astronomy and for
birding too. I just enjoyed the view, on everything I looked at – thanks Al’.
I really like the Ranger: pure essence
of Tele Vue. In some ways I prefer it to the TV-60, yes for its classic looks
but also because it grabs more light for deep sky.
