Tele
Vue Renaissance Review
Everyone loves a nice retro brass scope
for that clubby den or seaside terrace. Trouble is, most brass telescopes are …
well, rubbish really. Which, in fact, is where Tele Vue came in all those years
ago – supplying brass telescopes that really worked.
One of Tele Vue’s early brass
telescopes, one that innovatively used the quadruplet Petzval camera-lens
design, since much copied, was the Renaissance.
The Renaissance on test here is a
commemorative edition for the return of Halley’s Comet in 1986. Even though
it’s an early example, many of Tele Vue’s later signature features – the
focuser, clamshell, tube design - are already here. And like all Tele Vue’s, it
was made by hand in the USA. Unlike most later Tele Vues, this version comes as
a complete set, with an early version of the Panoramic mount as well as the
usual accessories (all with matching brass features).
I love classic scopes and have tested a
few, but optically classic scopes can be a mixed bag. Some (like the Swift I
tested a few years back) are top notch in every way. More often, classic scopes
evoke powerful nostalgia, but don’t really work that well. In this review, I
aim to find out which of those camps the Tele Vue Renaissance is in.
At
A Glance
|
Telescope |
Tele Vue
Renaissance |
|
Aperture |
100mm |
|
Focal
Length |
550mm |
|
Focal
Ratio |
F5.5 |
|
Length |
32” |
|
Weight |
~5 Kg |
Data from Tele Vue/Ed’ Ting/Me
What’s
in the Box?
The Renaissance came complete with a
hard case, mount and tripod, 2” diagonal and a 26mm Plossl eyepiece (and
instructions).
Design
and Build
The Renaissance went through several
iterations over its thirty year life, eventually morphing into a brass version
of the doublet TV-102. However, older models were all a quadruplet Petzval
design, like a Tele Vue Genesis but with brass bits.
Although this Renaissance was made at
Tele Vue’s earliest site at Pearl River, NY (they later moved to Suffern and
then Chester), there was an even earlier model, with a different style of
focuser body (less like modern Tele Vues). Fellow reviewer Ed’ Ting reported that
these earliest Renaissances performed a little worse than this one (Ed’s review
is nineteen years old now, but still well-worth seeking out). Still, this
version lacks the sliding dew-shield and fluorite element in the reducer that
benefited later versions.
This particular Renaissance version is
unusual in that it was produced to commemorate the much-hyped (though utterly
anticlimactic) return of Halley’s Comet in 1986. It has a brass plate on the
focuser saying so.
The Renaissance is, as it appears in the
pics, a beautiful thing with all those matching brass components. Tele Vues
from this period have a friendly, less serious feel than their later
imaging-oriented products. The (typewritten) instructions talk about wonder,
majesty and thrills, advising:
“The
Renaissance, like the era for which it was named, should be used for exploring
… anything and everything”.
Optics
Like the TV Genesis, the Renaissance is a Petzval. This means
it has four glass elements in two groups – an air-spaced 100mm doublet up front
and a cemented doublet reducer/flattener at the back (actually mounted in the
front of the focuser tube). The front doublet has a long focal length (probably
natively about ~F11) which the Petzval lens reduces by about half (down to a
fast 550mm, F5.5, in the Renaissance). This design reduces the OTA length as
well, but not by quite as much.
There is some misunderstanding about Petzvals. The
four-element design allows greater freedom to correct field curvature,
astigmatism and coma, so the Renaissance should have a flat field with stars in
focus and pin-point to the edge. But it doesn’t correct for chromatic
aberration: the false colour level is much the same as it would be with the
front doublet on its own. So, in this case, the false colour is similar to what
you might expect with an ~F11 achromatic doublet, i.e. decent but not perfect. The
modern NP-101 has a similar design but is a proper apochromat because it has an
F11 ED doublet up front which gives
very good false colour correction (even an F9 ED doublet, like TV’s own TV-102,
is a well-corrected scope).
The punch line to this is that the Renaissance,
like the Genesis, performs at best like a semi-apo, albeit a fast one that
combines a flat field with the reduced false colour of a slower objective.
In these earlier models, neither the doublet nor the Petzval
lens contain fluorite or ED glass. Later ones, termed ‘SDF’, had SD glass in the objective
(and fluorite in the reducer) and so much better correction. The Petzval lens in the SDF was also
a bit larger (purportedly 66mm instead of 60mm) for better coverage. The lenses
and cell appear similar to modern Tele Vues. The objective is multi coated, but
perhaps not quite to modern Tele Vue standards.
Optical design from the renaissance booklet.
Tube
The tube is
solid brass. That means it looks classy, but is heavy and acquires a dull
patina over time. It does show up finger marks. To keep it shiny you need to
polish it regularly with something like Brasso and then car wax (it hasn’t been
lacquered, which in a scope of this age is a good thing).
Like all Tele
Vues, the lens is held in a permanently collimated cell, nudged by hand into
alignment on an optical bench and then connected to the tube with blind rivets
– it sounds a bit crude, but typically works very well. I once saw an
(admittedly much smaller) Tele Vue refractor fall off its mount onto tarmac and
it suffered no ill effects, so it’s a robust approach.
Unlike modern
TVs, there is no sliding dew-shield, just a very short fixed one. The lens is
protected by a screw-fit metal cap, again familiar to all owners of TV scopes
(except for the TV-60).
As with all
Tele Vues, the tube has no baffles, but is lined with flocking paper that may
or may not be black-painted sandpaper – it looks like it. I have seen this
paper come loose, but in this case, it’s still in perfect condition.
Focuser
Despite being
over thirty, this Renaissance shares many features with recent Tele Vues,
including the focuser, which has a cast and machined body and a 2”
rack-and-pinion drawtube. The focuser is single speed, like other Tele Vues
until about a decade ago, but for the Renaissance the drawtube and focuser
wheels are made from brass to match the tube (as are the set screws on the
visual back and diagonal too) instead of chrome with ‘mag’ wheels.
Mounting
The
Renaissance has the black anodised clamshell that you find with all other Tele
Vue scopes (apart from the largest NP-127). The base of the clamshell has two
¼-20 threads spaced to match fit any Tele Vue mount, along with a single central
one. Studs thread into these holes and are secured to the swing cradle of the
mount by black Bakelite knobs. It’s all familiar TV and very classy. The only
thing this clamshell lacks is the finder dovetail you get with later examples.
The mount is
an attractive thing. It looks like a
modern Tele Vue mount, except with brass fittings. Actually, it’s a bit
different – an early version of Tele Vue’s lighter Panoramic mount. The swing
cradle is formed from one curved piece, not bolted together; and the bearings
are smaller. The tripod lacks a tray, having a spreader at the bottom made of
sheet metal instead. The wooden parts look like walnut, but may be stained ash.
The tripod is
less solid than a modern Tele Vue (perhaps due to the lack of a bracing tray):
it is all too easy to get it out of shape when moving it. Consequently,
compared to a Gibraltar (or even a modern TV Panoramic), this mount is a bit
more wobbly. All in all, the mount (surprisingly) is the least functional part
of this classic scope rig and the scope would perform even better on a
rock-solid (sorry) Gibraltar.
Clamshell has
three ¼-20 threads. The outer two hold the studs that attach the Renaissance to
the Panoramic mount.
Accessories
The
Renaissance comes with a brown hard case, lined with red velvet. The 2” mirror
diagonal and clamshell have unique matching brass thumb screws and so are part
of the ‘set’. Only one eyepiece was supplied, a 26mm Plossl that is an absolute
beauty.
In
Use – Daytime
Daytime views seem outstanding at
first, wide and flat and detailed. But look at high branches or a bird in
silhouette and there is quite a lot of proper, old-fashioned false colour:
apple green and purple. Now that so many spotting scopes and binoculars use ED
glass to reduce false colour, this is a reminder of the way things once were.
Even so, the Renaissance is sharper and brighter than most terrestrial scopes,
even today.
The Renaissance was intended for
daytime photography. Mine came with a glossy promo’ flier detailing its
photographic potential. Meanwhile, the instruction leaflet calls it, “… a fast
550mm F5.5 telephoto camera lens for 35mm single lens reflex cameras.”
This turns out to be true: the
Renaissance gives excellent, sharp photos. The false colour that limits it for
deep-sky astrophotography isn’t a problem at all.
For terrestrial photography, the
Renaissance makes a surprisingly sharp telephoto with minimal vignetting (APS-C
at least).
In
Use – Astrophotography
The wide flat field and fast F-ratio
would make for a great astrograph … and they do in the otherwise similar
NP-101.
The Renaissance (how I prefer typing
that name to ‘NP-101’) was designed for 35mm film, so on APS-C coverage is
unusually good for a Petzval and flatness is excellent too. But the Renaissance
shows what I mean when I talk about ‘violet bloat’. Almost every blue or white
(O-A) star has a bright blue halo. The result is genuinely attractive, but not
authentic.
The central region of Auriga with M36
is filled with sharp stars, but there is too much violet bloat for anything but
casual imaging.
Despite the small image scale, snaps of
the Moon come out very sharp indeed. Zoom right in to the image of a
Moon/Jupiter conjunction below and you can see Jupiter’s equatorial belts and a
hint of GRS – evidence of very good optics.
The
Renaissance makes casual deep sky snaps easy and rewarding and takes
super-sharp photos of the Moon. But it suffers too much chromatic aberration
for ‘serious’ imaging.
Moon and Jupiter: conjunction imaged
through Renaissance.
In
Use – The Night Sky
General
Observing Notes
The deep sky
view is a fraction less sparkly than an NP-101, blame the old-fashioned
coatings.
False colour
isn’t a problem for visual deep sky, but is more so for the Moon, planets and
imaging. This is one big reason why this isn’t a budget NP-101 (or other modern
Petzval - Takahashi FSQ etc).
With Tele Vue
eyepieces the field is very flat, but some others struggle with the steep F5.5
light cone. Though the field is flat, there is some distortion of off-axis
stars by coma and/or astigmatism you don’t get with a later TV petzval.
The focuser
is decent, but has a bit of image shift at high power (probably due to age and
wear). It’s not as buttery and precise as later single-speed TV focusers that
have the ‘mag wheels’. Depending on your eyes, there is just enough (or just
too little) outward travel to bring a 55mm Plossl to focus.
These earlier
clamshells don’t have a finder mount and there is no other obvious way to mount
a finder. But with a 550mm focal length giving a maximum field of 4.8° you just need a low power 2” eyepiece to find
stuff.
The dewshield
is very short and affords little protection – against dew, but also stray light
(and knocks). Later versions have a sliding dew shield like recent Tele Vues.
I think the
brass tube makes the Renaissance a bit heavier than the otherwise similar
Genesis model, but it is still easy to move about setup on its mount, ideal for
quick looks.
Cool
Down
Like other
Tele Vue quadruplets I have tested, cool down is fast and benign, again making
for a great quick-look scope.
Star
Test
The star test
looks good with near identical rings either side of focus. Some say Petzvals
can go out of collimation, but not this one. In fact, the only bad one I’ve
ever seen was an NP-127 and that may have been the result of a knock during
shipping (and Tele Vue fixed it for free anyway).
Basic optical
quality is very good, but in focus star images are a little less pinpoint than the
best modern scopes, due to the field-flattener.
The
Moon
At 21x with
the standard 26mm TV smooth-top Plossl, a gibbous Moon in a twilit sky looks
wonderful – sharp and detailed and full of contrast; there’s just a pale band
of violet around the limb to distinguish this from a modern apochromat.
By 37x with a
15mm Panoptic, that rim of false colour is a feature of the view, but the Moon
is still sharp and starting to show some of my favourite features, from
Alphonsus and Arzachel to Plato on the terminator.
With a 5mm
Nagler giving 110x, the Moon fills the view. Sharpness and detail are still
excellent, typical of any quality 4”, but whereas an NP-101 would be all whites
and greys and black space, that rim of purple is prominent. Overall, it’s still
a great view, though. Smaller craters and rilles are on view that you’d
struggle to see in a 3” scope of any quality. At this power the mount seems
wobblier than the (apparently similar) modern TV Gibraltar.
At 157x with
a 3.5mm Nagler T6, getting perfect focus is a hit and miss affair: the mount is
too wobbly, the focuser too coarse. The Renaissance wasn’t designed for this
kind of magnification, but still the Moon is sharp and full of detail once you
manage to tweak it in. I noted craterlets in Plato and Gassendi and lots of
rilles round about. However, the limb of the Moon is now surrounded by a border
of bright purple; the Lunar highlands have a purple wash too.
Venus
At 110x with
a 5mm Nagler, Venus shows a perfectly clean, brilliant crescent. There is none
of the softness, stray light, ghosts, spikes or problems getting focus which
Venus sometimes causes. But this is where the semi-apo in the Renaissance
shows, because surrounding that crescent is a bright halo of Imperial Purple.
Mars
Mars at only 4”
showed a crisp tiny ochre bauble at 110x with a 5mm Nagler, with just a trace
of stray red light around. Upping the power to 157x with a 3.5mm Nagler it
remained crisp, but at these powers the mount and focuser are the main issues
anyway.
Jupiter
At 157x with
a 3.5mm Nagler T6 Jupiter shows significant cloud belt structure, with the GRS
almost on the Meridian and a dark storm or two visible and a hint of banding in
the polar hoods. It’s a sharp view, but with a slightly yellowish cast and a
distinct purple border around the planet. It’s an enjoyable view, but not a
match for a modern 4” APO.
Deep
Sky
Tele Vue’s
Petzvals are always perfect for deep sky and the Renaissance, old though it may
be, is no exception. As usual, the 13mm Ethos is my favourite deep sky
eyepiece, giving 42x.
The Pleiades
are super-sparkly diamonds on velvet. The clusters (M36-38) in Auriga populous
and lovely with their surroundings full of stars to the field stop. Smaller
nebulae like the Ring in Lyra and globular clusters like M15 stand out well
from the background, but are most notable for the context that the wide, flat
field gives – surrounding them with sharp, pin-point star fields.
Viewing deep
sky like this, with one widefield eyepiece, no finder and just pushing the
scope around is addictively simple, a bit like binoculars: a real antidote to
your filter wheel, cooled camera, bias frame acquisition and whirring robot
mount.
A scope like
this isn’t ideal for doubles, but split Epsilon-Lyrae in mediocre seeing.
Summary
The Renaissance still looks fantastic
and overall performance is much, much
better than most classic scopes, especially if visual deep sky is your thing.
Pop in an Ethos or a Nagler and the deep sky views give a taste of that
immersive feel Tele Vue are famous for.
Don’t think the Renaissance won’t do
high powers on the Moon and planets, though – it will, sharp up to 100x and
beyond. But the Moon has a halo of purple at higher powers, as does Venus.
Daytime views are excellent too – bright and wide and detailed - but high
contrast areas reveal some false colour. The Renaissance gives great views, but
it is not a cut-price NP-101: it is at best a semi-apo.
Despite the flattener, off-axis
aberrations are slightly worse than recent Petzvals too, though the field is flat
for imaging and coverage excellent on APS-C. Deep-sky images reveal bright
violet bloating on blue-white stars. However, the Renaissance does work very
well for casual imaging, as a terrestrial telephoto lens or for snaps of the
Moon.
The other area in which the Renaissance
falls behind modern Tele Vue’s is the mount: it looks a lot like a Gibraltar,
but lacks the tray and is less solid and stable.
The Tele Vue Renaissance is a wonderful
‘classic’ scope and is highly recommended. Visually, it does everything well,
albeit with a bit of false colour. It is fast and has a flat field, so you can
have fun with terrestrial photography and astrophotography too, but there’s too
much false colour for ‘serious’ imaging.
Roger Vine 2018
