CELESTRON 70MM TRAVEL SCOPE REVIEW
By Ed De Mateo
I have an Orion XT6 Classic that I enjoy a lot, along with a modest
eyepiece collection. One of those eyepieces is a 40mm Plossl for
viewing wide expanses of sky at low power. Seeing the double cluster in
Perseus or the Pleiades within the eyepiece is breathtaking. Eventually
I realized that I wanted a short-focus, wide-field telescope which
would serve double duty as a spotting scope. It had to be something I
could easily pack up and take on a car trip to a tournament, and be
able to do double duty for night sky observing. Finally, it had to be
of reasonably good quality and inexpensive. After scouring the internet
and looking at a lot of options I found the Celestron 70mm Travel Scope
at Amazon for around $55 shipped. The scope package seemed to be just
what I was looking for and the price was right. Out came the credit
card and all the anticipation of waiting that follows.
The box finally arrived. Everything was stored inside the backpack,
which is well made and of good quality. Included are the scope, a 45
degree correct image diagonal, one 20mm and one 10mm eyepiece, a finder
scope, a tripod, a lens cleaning cloth and an excellent instruction
manual. Everything fits inside the backpack with plenty of room for
various necessary items, such as a red flashlight. There are additional
storage pockets in the backpack and a zippered pocket inside the lid
that can hold a small sky atlas and other papers.
Figure 1. View of the backpack (left) with the scope and other items inside (right).
The supplied ownerís manual is well written and very detailed, and
is translated in several different languages. It can be downloaded from
Celestronís website in PDF format. The manual does a good job of
covering the telescope assembly and basic operation, as well as having
sections covering astronomy basics and celestial observation.
Maintenance and specifications are found in the last pages.
The scope is a refractor with a 70mm (2.8Ē) aperture and fully
coated glass lenses. It has a short focal length of 400mm, enabling
lower magnification for a given eyepiece and more expansive views. Up
front the objective lenses are housed in a plastic lens cell with a
fixed dew shield. The lens cap is actually two pieces. With the center
piece removed it can be used as an aperture stop, helping to tone down
and enhance the view of bright objects, such as the moon or Venus. The
scope tube is made from aluminum and has an aluminum bracket with
standard ľ-20 threads for mounting on most camera tripods. The focuser
assembly is mostly made from plastic, keeping weight and cost down.
Figure 2. Celestron Travel Scope mounted on my photo tripod.
The included diagonal is a 45 degree correct image prism in an all
plastic housing. This diagonal design is primarily intended for
terrestrial observation. It can get uncomfortable when observing
targets with the scope near vertical. For daytime viewing the diagonal
is actually good, but at night there is noticeable green and purple
fringe coloring on the bright objects, especially with higher
magnification. This is to be expected when combining a correct image
prism with a fast focal ratio. Using the lens cap as an aperture stop
Two eyepieces are supplied in nice storage containers. The lenses
appear to be glass and the chromed barrels metallic, presumably
aluminum. The eyepiece bodies appear to be plastic, keeping weight and
cost down. The 20mm gives 20x magnification in this scope, the 10mm
giving 40x. Like the diagonal, I found that the eyepieces perform well
for daytime viewing and are acceptable for casual night observation.
Other than brand name and focal length, there are no evident markings
denoting design type.
Figure 3. The supplied 20mm and 10mm eyepieces (left) and prism diagonal (right).
I canít say much about the finderscope except that I donít use it.
It reminded me of the toy pirate scopes sold at dollar stores. I have
never had any trouble finding a target with the 20mm eyepiece.
The included tripod is a simple and compact photo tripod that fits
nicely in the backpack. When fully retracted it is a very usable and
stable unit. It has served me well on the shooting bench at the rifle
range, as well as on a table top for back yard astronomy. Fully extend
the legs and neck and it becomes totally useless. It is spindly and
seems like it will never stop shaking, and even a slight breeze will
make it dance. Itís also not quite tall enough for viewing standing.
During the day the performance of this scope is very good. The
images are sharp and clear, and the scope can focus from very close to
infinity. My favorite eyepiece is the 20mm and is the one I almost
exclusively use. It gives me a good wide field of view with sufficient
magnification to see detail. The 10mm eyepiece feels more restrictive
to me and does not give me the wide field of view that I like. Also, it
does show some purple fringe color, and if you are looking for it you
will definitely see it.
Figure 4. Transmission
tower seen in background from parking lot is 1.34 miles distant (left).
View through scope with 20mm eyepiece is good even though there was a
lot of haze and mirage (right).
At the shooting ranges, both gun and archery, I exclusively use the
20mm eyepiece. At the archery range I can see the full FITA target (the
big colorful one familiar to most) all the way out to 90 meters. The
view is clear and sharp, allowing me to see my arrows in the target. At
the shorter distances, down to 30 meters and less, the view is
expansive enough to be useful. I also use the scope as a spotter at the
rifle range, either on the bench with the tripod that comes with it, or
on the ground using my photo tripod. At 100 yards even the .22 caliber
bullet holes can be seen. At 500 meters I can clearly spot targets as
small as clay birds on the ground, and I am able to ascertain hits. At
1,000 yards I also like the 20mm eyepiece. I can see the target area
and the steel swingers, 10Ē and smaller, and observe hits. One negative
is that this scope is not sealed and water can possibly enter if it
should start to pour. But then again, it isnít a high end scope and you
can dry it out.
Viewing birds and other flora and fauna is a treat with this scope.
I was surprised by the level of clarity and detail that can be seen.
Iím not a birder or nature observer but for casual viewing this scope
will give a more than satisfactory view.
Figure 5. I photographed these two birds in my back yard at an approximate distance of 20 feet.
The manual that comes with this scope states that it ďÖis ideal for terrestrial as well as very casual astronomical observation.Ē
I couldnít agree more with that statement. When using the scope with
the supplied 45 degree diagonal it can start to get awkward or
uncomfortable as the targets get closer to vertical. Itís no different
than other scopes using a 45 degree diagonal. The diagonal itself uses
a correct image prism that allows you to see the image as you would
with your naked eyes. The complexity of the prism and short focal
length combine to introduce false color in the fringe of bright objects
and some image and brightness degradation. The view is actually quite
good, just donít expect it to rival fine refractor scopes. The
eyepieces are also not the finest in quality but are usable and give a
good view of objects in the night sky. The 20mm gives a more expansive
view and is my preferred eyepiece of the two. The 10mm gives a slightly
wavy image that is a bit on the dim side. Itís OK, but I really prefer
the 20mm eyepiece.
LUNAR AND PLANETARY
The moon is a big brilliant target that many people enjoy observing.
This scope does a good job on the lunar surface with either of the two
eyepieces. Views are reasonably sharp and clear, showing good surface
detail. Some false coloring is evident, but not so bad that it spoils
the view. Using the scope cap as an aperture mask almost totally
eliminates the coloring while taming the image brightness.
Figure 6. Lunar photos taken through the eyepiece with a digital pocket camera.
Venus is another brilliant target that benefits from stopping down
the aperture. The green and purple fringe coloring can be very
pronounced without the aperture mask. With the 10mm eyepiece the
planetary phase becomes evident, Venus looking like a small and bright
Figure 7. Venus through the eyepiece, showing fringe coloring on both sides of focus.
The scope also does a decent job on the two naked eye gas giants.
Viewing Saturn with the 20mm eyepiece reveals a small disk with the
rings appearing as a line through it. Increasing the magnification to
40x with the 10mm eyepiece gives a surprisingly good view. Jupiter is
also a good target with either eyepiece. The four large moons are
visible, and with good seeing and the 10mm eyepiece one of the bands
can be seen.
Open clusters are one area where this little scope performs well.
The lower magnification of the 20mm eyepiece is great for taking in
wide views of the night sky. NGC6231 is a small open cluster in
Scorpius that looks like a pile of diamonds shining in the night sky.
M7 and M6 are more spread out than NGC6231, but can still be observed
well in the eyepiece. Views of the open clusters through the 20mm
eyepiece are bright and sharp. I tried the 10mm eyepiece out of
curiosity but the view was dim and not very sharp. With the higher
magnification, the 10mm is not the eyepiece of choice for open clusters.
Globular clusters, as well as galaxies, are too dim for this little
scope. I tried looking at globular cluster M22 in Sagittarius but it
appeared as a very faint, almost ghostly image. Maybe in a dark sky
site, but in my backyard I was pushing the little scope way beyond what
it was intended for.
This is another area where the scope performed well with the 20mm
eyepiece. Albireo separates nicely at 20x and the yellow and blue
colors of the stars were beautiful. The image is bright and sharp, even
in my light polluted environment. Viewing the double double in Lyra
through the 20mm eyepiece also gave a sharp and bright image, although
at 20x the tighter doubles are not going to be resolved. The 10mm
eyepiece was again a big disappointment with a dim and fuzzy view, and
itís not powerful enough to resolve tight doubles anyway.
The Celestron 70mm Travel Scope is a reasonably good low cost unit
intended for daytime viewing and casual astronomical observation. The
package is light and compact, primarily designed for travel. All
components can be stored in the backpack, which has enough room for
accessories. It serves well as a spotting scope at the rifle or archery
range, and for impromptu views of flora and fauna. At night the scope
will give reasonable performance on a variety of astronomy targets
should the urge strike. Plastics are used extensively, especially in
the focuser assembly, but it helps to keep weight and cost down.
Performance of the scope is surprisingly good. I was impressed with
the views using the supplied 20mm eyepiece, which are reasonably sharp
and bright. I find that it is the only eyepiece I use at the gun and
archery ranges, as well as at night for astronomy. The 10mm eyepiece
was a disappointment with its dim and not so sharp views. Good thing I
donít find much use for it. The supplied tripod, if extended, can be a
source of frustration. Keep in mind it was meant to fit in the backpack.
This scope is a good option for someone who wants an inexpensive
scope that can be stored on a closet shelf in a tiny apartment or
efficiency, or kept in a car or pickup truck for spur of the moment
views. Traveling to tournaments is a breeze with everything stored in
the backpack. Finally, a couple of inexpensive Plossl eyepieces and a
prism star diagonal will really make this scope shine, improving
Clear skies to all,