Carton
Comet Seeker 60/710 Review
I have been interested in Carton
telescopes for a long time, but this is my first opportunity to review one.
On casual inspection this may seem like
any other 1970s or 1980s Japanese small refractor. It looks much like the 3” Tasco mum bought me in 1978. In fact, Carton made (or
perhaps more accurately bought in) high quality optics and mechanicals, more in
common with say Swift or Pentax than Tasco, albeit a
rung down from Takahashi or Nikon.
This particular Carton was likely one
of those models brought out to cash in on the return of Halley’s Comet in 1986.
The comet was a squib, but we still have some nice scopes from that era,
including the commemorative Tele Vue Renaissance I reviewed. Let’s see how this
little Carton compares.
At
A Glance
|
Telescope |
Carton
Comet Seeker |
|
Aperture |
60mm |
|
Focal
Length |
710mm |
|
Focal
Ratio |
~F12 |
|
Length |
730mm
(OTA) |
|
Weight |
About 7Kg
incl. mount |
Data from Me.
What’s
in the Box?
Part of the
Carton’s appeal for me was ... well, its carton. It came in the original one,
complete with all its copious accessories, even down to the sealed lens cloth. Also in amongst all that polystyrene are things like a
camera adapter and solar projection kit – a classic scope constructor toy!
Design
and Build
The Carton has that style of just about
all Japanese consumer scopes from the 1960s through the 1980s – it’s an
intensely nostalgic look for Boomers and Gen Xers who grew up with one in the
bedroom alongside Patrick Moore’s books, a poster of Mount Palomar and an Airfix Saturn V.
Long white tube, Boxwood tripod, black enamelled mount – it’s all there.
The subtle difference between this and
the average Tasco or Prinz or whatever (much as I
love ‘em) is that almost everything on the Carton is
of high quality and works as it should. However, don’t think this is Swift or
Takahashi quality – it isn’t. Mechanically it is inferior to a Unitron (which
had beautiful mounts and hardware) too, but not optically or functionally, as
we will see.
Optics
The
objective is a completely standard 60mm F12 (actually 710mm F.L.). It’s a foil
spaced (not cemented) achromatic Fraunhofer doublet with single coatings.
Lenses like
this were allegedly churned out by numerous backstreet opticians in and around
Tokyo, but quality varied from dubious (Unitron and Tasco,
amongst others) to downright outstanding (e.g. Swift). This one, as we will
see, is in the middle – good, but not at Swift’s level.
Comet Seeker
objective is a typical foil spaced Fraunhofer achromat.
Tube
The white
enamelled tube is very typical for the period, but everything is metal, lens
ring and dew shield included. The focuser attaches with screws, but the lens
ring and shield thread on.
Focuser
The focuser
is one of the areas where Carton shows its roots as a ‘serious’ telescope
maker. All made of metal, the focuser is a little stiff from dry grease, but it
is smooth and accurate despite having loads of travel – no free play or
backlash or image shift here. But like most scopes of the era, it’s 0.965”, so
won’t easily take modern eyepieces and diagonals.
Focuser has enough
travel for any eyepiece or straight-through viewing, is smooth and stable.
Mount is
basic but solid, the controls smooth and accurate.
Mounting
The mount is
a typical small German equatorial. It has slow motion controls, but no way to
fit a drive motor (the one on my period Tasco didn’t
work anyway). It sits on a typical wooden tripod with an eyepiece tray. The
tripod fully extended is good for viewing whilst sitting, not standing.
The mount
doesn’t look quite like a Tasco, Prinz, Swift or any
other from the period, so it’s doubtless Carton’s own. Some of the casting look
a little rough to keep the cost down, but functionally it’s excellent. The slo-mo’ controls are well made and work smoothly, the mount
and tripod are fully up to damping vibes at any magnification the scope can
take (even a Swift can’t make that boast!). Even so, the whole rig is one-hand
portable.
Carton’s
light and slim OTA sits in a clamshell that works a bit like a Tak’s, but with a thumb screw and no quick release catch.
Accessories
Period
scopes like this always shipped with plenty of accessories, but this Carton
really got the lot:
·
Mount with slo-mo’ controls, tripod, eyepiece tray and tube ring
·
A decent 6x30
finder with proper optics in a quick release dovetail
·
Tube weight
for balancing a camera
·
Camera mount
for tracking an SLR that fits into the finder dovetail (and an identical one on
the clamshell)
·
Solar
projection screen kit, that again mounts into the finder dovetail (can’t use
the finder for solar, right!)
·
Quality
prism diagonal with a twist lock that looks identical to a Takahashi
·
Three M.H. eyepieces
·
Lens cap
with a stop-down aperture for solar
·
Sun (dangerous – never use one of these!!) and Moon filters
·
Logoed lens
cloth
·
Manual
The Carton
shipped with three nicely-made, branded 0.965” eyepieces. All three are
sensible focal lengths (no 1000x magnification here, thankfully!) at 20mm,
12.5mm and 9mm. They are decent quality too, but Modified Huygenians
are a basic two lens design (narrow field, poor performance off-axis) and have
single coatings. Any multi-coated Orthoscopics will
be a huge upgrade for someone looking to use a scope like this.
Eyepieces
are of the very basic modified Huygenian (M.H./H.M.) design
(diagram from the Carton manual).
Solar
projection screen.
In
Use – Daytime
The Swift
Model 838 I reviewed – a 50mm F15 – performed like a semi-apochromat with
minimal false colour. But here, increasing the aperture to 60mm and dropping
the focal ration to F12 means it’s an achromat during the day. Low contrast
views are sharp and good, but high contrast subjects reveal plenty of apple and
blueberry hues.
In
Use – Astrophotography
The camera
mount offers the interesting possibility of taking long-exposure tracked
photographs of star fields whilst using the scope for guiding.
You might
not think of a scope like this for proper astrophotography, but this being
Carton they actually made 0.965” camera adapters and an eyepiece projection
device. The focuser is certainly solid enough to take a light SLR or a
viewfinder camera like the Agfa shown. I didn’t have those accessories to try
this out though.
Carton
accessories for prime focus or eyepiece projection.
Camera mount
allows the Comet Seeker to be used as a guider.
In
Use – The Night Sky
General
Observing Notes
Just in the course
of testing it, I suspect the Comet Seeker has seen more of the night sky than
during it’s previous 35 years. That’s a shame. But
part of the problem are the standard eyepieces (see above). So
for this review I mostly used my set of 0.965” Takahashi MC Orthos.
The mount’s slo-mo controls work accurately and free of backlash or
play, if a little stiffly (due to dry old grease I expect). The mount damps
vibes fine up to the ~100x the scope will realistically take.
Unlike some period scopes, everything works well, from the mount to the
focuser. You could really use and enjoy the Comet Seeker.
Cool
Down
Like any
small refractor, cool down is super quick, just minutes from a warm house.
Star
Test
The star
test is good, with near identical evenly illuminated rings either side of focus
and a nice Airy disk and faint single ring in focus.
This is much
better than the 60mm Unitron I tested. Whichever Japanese optical shops were
making the lenses for Carton were clearly doing a better job than the ones
Unitron used. It’s not just theoretical either. The Carton takes high powers on
the Moon and planets much better than the Unitron. However, this Carton isn’t
in the league of the little Swift Model 838 I used to own.
The
Moon
With a Takahashi
7mm MC Ortho’ giving 101x, the Moon is excellent – detailed and sharp, if a
little dimmer than a modern multi-coated 60mm. And image breakdown does occur
at lower powers than a really fine optic, like the Swift Model 838 had, so that
my next power up – 142x with the 5mm MC Ortho’ – isn’t really usable.
At F12, the
Carton does show a little false colour on the Moon, noticeable mainly in tinge
of purple to highlights which reduces contrast.
Nonetheless,
on a 13-day Moon, I enjoyed exploring Oceanus Procellarum: Aristarchus’ white stripes and Kepler with its
splashy rays and weird Reiner Gamma.
Later in the
lunation, a 22-day Moon with Albategnius on the
terminator showed the Apennines in sharp detail, the dark patches in Alphonsus
and the Hyginus rille; the slumped walls and peak of Tycho and crater arc of Clavius in the far south.
The Carton
may have been designed for low-power comet sweeping, but its objective delivers
high-power views that better most consumer scopes of the era, even if they fall
a little short of, say, a Zeiss Telementor or that Swift.
Mars
Mars was the only planet easily accessible. At 22” just after
opposition, viewed through a 0.965” Takahashi diagonal and a 7mm Tak’ MC Ortho eyepiece giving 101x, gave a crisp and low
false-colour view with a hint of albedo markings. The accurate and shift-free
focuser made finding perfect focus easy.
Deep
Sky
Despite its
name, deep sky is not the Comet Seeker’s forte, because it’s a bit dim due to
the single coated lens. This is an interesting lesson in the importance of
multi coatings. The Carton is so much dimmer than my Takahashi 60mm scopes I
even wondered if there was vignetting from the focuser tube. So
I measured it, but nope – the exit pupil is spot on.
The manual
shows a few DSOs to try – the Andromeda Galaxy (M31), the Great Nebula in Orion
(M42), the Double Cluster and the Pleiades. So I
followed its lead ...
The Pleiades
and Hyades looked nicely sharp and sparkly at 28x through a Takahashi 25mm MC
Ortho.
The Great
Orion Nebula looked quite good too, at 28x, with the Trapezium nicely resolved
and structure in the nebulosity with averted vision. I was surprised that the
standard 20mm H.M. eyepiece was just as sharp on axis, though it distorted stars near the field stop.
I found the
Double Cluster, but it did seem a bit dim and lacklustre compared with the view
through a modern 60mm, likewise M31. The open clusters in Auriga, M35 through
M38, were the same, requiring averted vision to fully resolve them, even with a
Takahashi diagonal and eyepiece.
Albireo
showed its colours well though and split nicely. At 142x with a 7mm ortho, at
the very limits of what the Comet Seeker will take, I just about split one
component of Epsilon Lyrae.
Summary
This little
Carton was likely the budget end of their telescope offerings, a consumer kit
to cash-in on the 1986 comet craze. Even so, it’s a cut above most similar
looking Japanese scopes of the 1970s and 1980s, because it has optics and
mechanicals that work properly. And yet it has the classic look that reminds
me so nostalgically of the Tasco 3” refractor I
bullied my mum into buying so long ago.
Optically, the
Comet Seeker lies somewhere between that Tasco and a
really fine achromat like a Swift. It is quite up to lunar and planetary views
of 100x and gives very good views, but it can’t take insanely high powers for
its aperture the way the very best (Swift, Zeiss etc) can, probably due to a
few cut corners in final polishing (the basic objective figure is excellent).
It’s good enough to benefit from better eyepieces than the modified Huygenians in the box. Any quality 0.965” ortho’s would do
– say Vixen’s if you don’t want to spend (or can’t find) Takahashi’s.
The Carton is
totally usable today. If you like the Moon and planets, it would make a great
quick look scope with a nostalgic twist. The Carton’s classic looks and quality
build should be good for persuading your significant other to allow it a place
in the corner of the drawing room for a touch of retro astro-class
at modest expense.
Don’t buy a
scope like this one for quick looks at the deep sky though: it’s single coated
lens and lack of available wide field eyepieces count against it.
For an inexpensive quick look
retro’-scope, with better real-world performance than a Tasco
(or even the Unitron I reviewed), the Carton looks the part and works well for
the Moon and planets. Not, however, for deep sky (ironically) due to its single
coated objective.
