Tele
Vue TV-85 Review
The Astro Physics Traveler
was my perfect travel apo’ in all but one respect – weight. Insanely compact in
its case, it still needed a hefty mount which made it hard to travel with alone
(my checked bag containing only the mount weighed 20 Kg). The Traveler was just too weighty for smaller alt-az mounts like the Vixen Porta.
Foolishly I sold the Traveler, thinking I might replace it with the lighter
Stowaway (finally I did – seven years later!) Then there’s
the Baader Travel Companion – similar spec, same Unobtanium.
Meanwhile, most 100mm scopes are just too large to carry on board without
disassembly (see photo below).
I was moaning about this to a friend.
He shrugged and said, ‘Buy a TV-85’. So I did.
I went through a Tele Vue phase more
than a decade ago, but somehow missed out on the 85mm version of TV’s ED
doublet. So, in a fit of nostalgia, I rejected a new one and bought a
completely mint and unused example from that era, with its classic chrome-tubed
focuser.
Now it’s true
that ED doublets, rare and exotic 15 years ago, are cheap and commonplace now. So is the TV-85 still relevant in an age of Chinese mass
production? Let’s find out ...
TV-85 alongside Takahashi’s most
compact 100mm, the FC-100DZ (dew shield retracted on both).
Takahashi’s FC-100 Classic is another
step-up in size: I compare these scopes throughout this review.
TV-85 and AP Stowaway for comparison: Stowaway
is slightly shorter but heavier.
At A Glance
|
Telescope |
TV-85 |
|
Aperture |
85mm |
|
Focal
Length |
600mm |
|
Focal
Ratio |
F7.1 |
|
Length |
485mm, 19”
(case 600mm, 23.5”) |
|
Weight |
~3.1 Kg
incl. ring no dovetail |
Data from TV/Me.
What’s in the Box?
Tele Vues come in a basic logoed crate, seen here with an
NP-101.
Design
and Build
Perhaps more than any other brand, Tele
Vue scopes have a consistent design and finish that extends from early examples
like the 1980s Oracle right up to the current range-topping NP-127: cream
pebble-coat tubes, CNC rings and in-house focusers, slim sliding dew-shields
and thread-on caps.
The TV-85 was introduced some twenty
years back, along with the TV-76, to extend TV’s range into middle sizes,
plugging the gap between the semi-apo’ Pronto and larger TV-101.
Today, the NP-101 and NP-127 retain the
flat-field quadruplet optics of the original Genesis, whilst the TV-60, TV-76 and TV-85 all have ‘simple’ ED doublets (but see below).
At one time, Tele Vue also made a 4” doublet, the TV-102, but it’s been discontinued for some time.
The TV-85 arguably hits the sweet spot
in the range, explaining its popularity. Properly carry-on portable (unlike an
NP-101), it nevertheless has usefully more light gathering, resolving power and
image scale than the TV-76.
Styling, fit
and finish are classic Tele Vue.
Optics
Now that ED
doublets are ubiquitous, it’s easy to forget that Tele
Vue pioneered them. Some early TV objectives – like the Ranger and Pronto -
used barely-ED glasses of limited effectiveness, but the more recent TV-76 and TV-85
have ‘proper’ ED crowns. I assumed the TV-85 would use FPL-53, a widely used ED
crown glass and one of the best, but it seems not.
ED glasses
tend to have distinctive laser scatter levels and I had a chunk of premium ED
glass (Ohara S-FPL53) at hand – the one in a Sky-Watcher 120ED. The ED crown in the TV-85 scattered a
lot more laser light than the one in the 120 ED, suggesting the stuff in the
TV-85 is a cheaper glass, perhaps FPL-51?
The TV-85 lens
has similar false colour levels to the 120ED (perhaps even a little worse)
despite its smaller aperture and large air gap. A lower grade of ED glass could
explain why.
I also
assumed the TV-85 would be a scaled-up version of the TV-76 objective, with a
narrow air-gap between crown and flint. But again, not so. Instead, the TV-85
adopts the lens design of the TV-102: a laser reveals a large air gap (1cm or
more) between the elements – see photo below. This approach allows for better
correction.
Whilst the
TV-76 is fairly fast at F6.3, the TV-85’s 600mm focal
length gives a slower F7.1. The now defunct TV-102 was much slower at F8.6.
This increase of f-ratio with aperture simply reflects the reality that
chromatic aberrations worsen with increasing aperture.
Despite
being an older model, the lens coatings appear of the highest quality, with a
very transparent greenish-blue hue, identical to recent Tele Vue eyepieces in
fact.
Lens cell
incorporates two knife-edge baffles to complement the usual flocking paper
behind it.
TV-76 vs TV-85
(right): note the large spacer and air gap in the 85’s objective.
Laser test
confirms the large air gap, suggests a lower grade crown than FPL-53.
Tube
Tele Vue’s OTAs
have a unique style that I really like. In this case, the main tube is the same
3” diameter as the TV-76 (and Pronto before it), with
the same textured ivory powder coat that looks great and is exceptionally
durable. The focuser and lens cell/dew shield assembly are finished in a satin
black powder coat with a finer texture (the earliest examples have gloss
anodising).
Unlike the
TV-76, the 85 gets a larger, flared lens cell to accommodate the bigger optic
with its widely spaced elements.
The focuser
threads on, but just like every other Tele Vue the lens cell is nudged into
perfect collimation on the optical bench then held with hefty rivets (or
possibly blinded screws). It makes for a very rugged telescope and I’ve seen small Tele Vues take
substantial knocks without going out of collimation.
The lens
cell assembly is built in one piece, much like a whole TV-60, with machined-in
ridges and a baffle behind the lens. But the baffle-less tube itself is lined
with the TV-usual blackened sandpaper. The dew shield is also lined with
flocking material to kill stray light.
The TV-85 is
remarkably compact and quite light at 3.1 Kg including the clamshell-style
ring. It’s lighter than most travel refractors in the
90-100mm range and as compact as the smallest (about the same size as an AP
Stowaway, but 0.5 Kg lighter – see above).
Overall fit
and finish is absolutely first rate.
Compact
extending dew shield is a classic Tele Vue feature.
Focuser
This has an intermediate
style of rack-and-pinion Tele Vue focuser, introduced in 2005. It retains the chromed
drawtube and single speed of the original, but has twin lock screws that
operate a lock ring within the focuser body, rather than the single, 12-o’clock
screw and clamp-pad of the original. This gives better stability and resistance
to slop under heavy loads (it’s rated to 2.3 Kg), but
it is stiffer and a little less fluid in feel than the original.
From 2011,
Tele Vue changed the focuser again. Latest versions have a different style of
focuser body, a coated (rather than chromed) drawtube and a fine focus as
standard. It’s similar to the focuser fitted to the
larger imaging scopes (see example on an NP-127 below). Another difference from
the original style of focuser is in the visual back. A 2” has always been
standard, but in the chrome drawtube design it was bolted to the focuser tube.
In the most recent version it’s integral, again for
improved rigidity with heavy cameras or bino’s.
Personally,
I do prefer the style of the chrome-drawtube focusers with those much-copied
but still gorgeous twin ‘mag’ wheels, which is why I bought this one. However,
the dual-speed version may be better for imagers (though I had no problems
getting perfect focus with the single speed).
Travel is
adequate at 60mm, so that a 55mm Plossl sharpens up
in a 2” diagonal (just). But you’ll need an extension
for imaging and some eyepiece/diagonal combinations might not come to focus.
Classic
chrome-tube focuser has 60mm of travel.
Recent
versions (post 2011) get a dual-speed focuser much like this one on an NP-127.
Mounting
The hefty
CNC 3” ring (that also fits the TV-76) needs an Allen key to fit or remove, but
can be tightened with a wing nut. The fittings were ferrous in the first
versions, but more modern ones get the stainless Allen bolt and wing nut you
see here.
The base of
the ring has three ¼-20 threaded holes. The centre is for a photo head (it
would need to be a big ‘un), the other two for direct attachment to a Tele Vue
mount or a dovetail. Tele Vue’s own Vixen dovetail is super-compact and has the
added convenience of replicating the threads on the clam, so you can transfer
the TV-85 to a Tele Vue mount without removing it.
Most smaller
mounts will take the TV-85, but not the very smallest: it’s
compact but quite heavy. Among Tele Vue’s own mounts, at least a Panoramic is
recommended. My Vixen SX2 takes it without a counterweight. The Vixen Porta (see
above) vibed too much for high powers.
TV-85 is
ultra-stable, needs no counterweight on a Vixen SX2.
Tele Vue’s
own Panoramic (seen here with TV-76) is one of numerous smaller mount options
for the TV-85.
Accessories
The carry-on
soft case is standard and just a scaled version of the TV-76 version. It’s functional, with space for the ring and a diagonal,
along with holes for various eyepiece sizes.
The TV-85
can be bought as a set with the clamshell, a 2” diagonal and a 20mm Plossl eyepiece; or as just the OTA in a case.
Tele Vue’s
huge range of eyepieces hardly needs mentioning, likewise their premium mirror
diagonals. But they produce a variety of other accessories, including a 0.8x
reducer and a high-end red-dot finder called Starbeam
that fits into one of the shallow dovetails on top of the ring. Alternatively,
TV make a matching generic finder base.
Soft case is
carry-on size and has plenty of space for accessories.
In
Use – Daytime
I compared
the TV-85 with a Takahashi FC-100 classic and FC-100DZ (both F8 fluorite
doublets) on winter branches against a brilliant clear winter sky, all with 7mm
Nagler giving 114x in both Takahashis
and just 85x in the TV-85.
The DZ showed
essentially no false colour in or out of focus. The FC-100 Classic showed just
a trace either side, despite being a simple foil-spaced design. The TV-85 showed
minor green and purple fringing on the branches either side of focus and in out
of focus parts of the view.
This is not really
a criticism of the TV-85: the TV-85 gives truly wonderful daytime views at
spotting-scope magnifications and works surprisingly well as a terrestrial
telephoto lens, with excellent full-frame coverage. What’s
more, my usual branches shot shows very minor false colour.
TV-85
full-frame coverage is surprisingly good.
Branches show
subdued false colour. Second is 100% crop of central area straight from the
camera (no sharpening or processing).
In
Use – Astrophotography
I had no
trouble getting perfect live-view focus with the standard single speed focuser
and found no evidence of slop or image shift. Big CCD cameras might benefit
from the heftier imaging system focuser, but for my full-frame DSLR the
standard setup works fine.
Across a full
frame, stars elongate off-axis but vignetting is minor. Violet bloat is
reasonable. Images on an APS-C chip should be decent, even without a reducer. I’d expect the TV-85 to make a decent imaging machine with
the 0.8x reducer; I’ll update this review once I’ve acquired one.
Image scale
is a bit small for the Moon, but still sharp and detailed.
Pleiades with
TV-85: 60s at ISO 3200 Canon EOS 6D Mark II. Single frame, no processing.
In
Use – Observing the Night Sky
General
Observing Notes
After lots
of observing with some larger refractors, the first thing that really hit me
with the TV-85 is how easy it is to throw around the sky, quickly and easily
moving from object to object. What’s more, that short
OTA means the eyepiece is almost always in a convenient position, with no need
to change tripod height. Combined with the quick cooldown, this makes the TV-85
a much easier tool for quick looks when you’re tired
or have limited time. A bigger scope may show you more, but you’ll
use it (a lot) less.
Past Tele Vues have annoyed me with their hard to thread and screechy
dew caps, but this TV-85’s is easy to get on and off and is mostly
screech-free.
The focuser
is typically excellent, with a smooth precise action and no slop or significant
image shift. There’s enough travel to (just) bring a
55mm Plossl to focus. I found no need for a fine
focuser for visual use.
The only
negative point I noted was that the short dew shield fails to completely cut
veiling flare when viewing around a bright Moon, despite all that flocking and
baffling.
The TV-85
gives a maximum true field of 4.4° with a 55mm Plossl – about the same maximum field as a pair of 15x
bino’s – but realistically you might want to stick with lighter 1.25” eyepieces
in which case 2.6° is your maximum. That’s a bit
narrow for star hopping – learn from my mistake and buy a finder at the outset!
I’m a bit finder sceptic for small scopes, but at this focal length a finder starts to become useful.
Cool
Down
Cooldown is
rapid and benign, without the pinched optics or severe spherical aberration
exhibited by some objectives. Don’t underestimate this
for a travel or quick-look scope: some larger doublets and smaller (esp.
air-spaced) triplets take much longer to cool. I put a Sky-Watcher 120 ED out
to cool at the same time as the TV-85; half an hour later, I’d
already completed a quick session with the TV-85 but the 120 ED was still
pouring hot air from its visual back and giving mushy views.
Star
Test
I’ve seen Tele Vues with just average star tests, but this is very good
with almost identical, evenly illuminated rings either side. This optical
excellence plays out in use, with exceptionally intense bright stars (near
perfect optics like this throw more light into a narrow central region of the
in-focus diffraction pattern).
The
Moon
On a 13-day
gibbous Moon, I noted craterlets and rilles in Gassendi, ruined Doppelmayer on
the other side of Mare Humorum and nearby Rima Sirsalis. Further south, Baily was full of shadowed detail.
Aristarchus showed its bright stripes and lots of landscape features on the
plateau. Up north the interesting Gruithuisen domes
stood out clear and explorable from Mare Imbrium. A
last quarter Moon showed the slumps in Tycho’s walls and marvellous sunset
views of the central peak’s shadow crossing the whole width of Alphonsus.
The TV-85 is
moving into 4” territory with its detailed lunar views – significantly better
for exploring than a 60mm refractor. However, I did notice that the Tak’ FC-100 Classic I was testing alongside bled less stray
light from the limb into space and showed more detail too.
I noted that
the short dewshield caused veiling flare when viewing
near the Moon.
Mars
The only planet around at the time of this review, I’ll
hopefully update this review as the others return to the night sky.
Mars at 13.5” and 200x with the 3mm setting of a 3-6 Nagler zoom looked perfectly sharp, with a touch of deep
red false colour only outside focus, much like a large ED triplet (my TMB 175). The
prominent albedo marking of Syrtis Major was very evident, the Martian disk
sharply defined.
Just after Christmas 2020, with Mars reduced to just 10.8” and on a
frosty evening with thin high cloud, the seeing steadied and the TV-85 again
showed a pin-sharp gibbous Mars at 150x with a 4mm Zeiss Abbe Ortho’ and 200x
with the 3mm Nagler Zoom. I felt the ZAO gave a
slightly crisper, more contrasty view. A stripe of albedo markings were visible around the equator, including dark Mare Sirenum and the diffuse halo around Solis Lacus.
So the TV-85 gave great
views of Mars in good seeing. However, there was minor false colour – dark red
blur inside focus and flaring off into the turbulence, marring the view as the
focus point shifted about. Again, this is typical of ED doublets, but was notably
absent in the FC-100.
Deep
Sky
Tele Vues always seem to like the deep sky, so on a clear dark
winter’s night just after New Year, I took the TV-85 on a thorough tour of
brighter DSOs from my south-facing balcony.
I started
with Hercules, already getting low in the west, for a look at the large
globular cluster M13. With a Panoptic 19mm – my favourite deep sky eyepiece
with the TV-85 – giving 32x, it showed up as bright diffuse ball, starting to
resolve into a star cloud at the outer edges with averted vision. Another
globular, M15 to the right of star Enif in Pegasus,
was much smaller and less impressive though, still a fuzzy blob at this
aperture.
Moving over
to Lyra, the TV-85 gave me one of the best splits of the Double Double I’ve seen in a small scope
– lots of black space between components in both systems at 150x with a Nagler Zoom set at 4mm. Nearby, the Ring Nebula showed why
3-4” refractors can work so well for deep sky: with enough aperture to show the
ring easily with direct vision, but enough field (2° with that 19mm Panoptic) to give loads of context
and every star in the field a perfect glitteringly brilliant pinpoint.
In the east,
the Great Nebula in Orion (M42) revealed more structure in the inner nebula
than through a 60-70mm scope and even hints of colour. The low power gave a
wide flat field, encompassing much of Orion’s sword region but still easily
splitting the main Trapezium stars. Likewise, Rigel was an easy split with its
fainter companion floating clear of the main star’s brilliant Airy disk and
diffraction rings at 150x.
A focal
ratio of F7 is a nice compromise between speed (for imaging) and a natively
flattish field which perfectly framed the glitteringly icy Pleiades, scintillating
within misty blue nebulosity, to give a really stunning
view of M45 at 32x. But left a bit in Taurus and the Crab Nebula M1, a
supernova remnant, remained a dim fuzzy blob at any magnification.
The open
clusters running up through Auriga – M35, M37, M36 and M38 – were resolved as
starbursts with direct vision. The starfish (M36) and M35 were particularly
lovely at this aperture.
The field is roomy
enough to accommodate most of the huge Andromeda Galaxy and its companion, both
of which looked excellent with the main galaxy showing its core brighter and
more defined than through smaller scopes.
Overall,
the TV-85 performed at a lower level than a premium 100mm F8 fluorite doublet
like the FC-100 – a bit more false colour on Mars, a
bit more stray light on the Moon, less reach for deep sky; but then it’s much
more compact. The TV-85 is a great compromise between the size of a 3” and the
performance of a 4”.
TV-85
mounted in my dome for imaging.
Summary
Twenty years
on, the TV-85 remains one of the best travel scopes. It is small and light and
rugged, with enough aperture and good enough correction for most purposes: from
deep sky imaging at remote sites though viewing eclipses and conjunctions;
birding and nature viewing too.
Optical
quality is very high, but there is more false colour
on Mars than an F8 fluorite doublet and less lunar contrast and detail. The
compact tube suffers a little more from stray light than a big fully baffled
one like the FC-100’s.
Then there’s the AP Stowaway. Almost identical to the TV-85 in
size, the Stowaway has better correction, a better focuser and better baffling
against stray light. But then the Stowaway is much more expensive and very hard
to obtain, about half a kilo heavier.
The TV-85 is
one of those iconic telescopes that still doesn’t
really have a competitor: the alternatives are mostly larger, heavier or unobtainable.
My friend was right: if you’re plotting to prize a
Stowaway from the clutches of a collector, just buy a TV-85.
As a rugged multi-purpose travel scope,
or an all-round quick look scope, the TV-85 is highly recommended and remains
hard to beat. With a reducer it should make a decent small imaging apo’ too.
