Build Your Own Telescope For The Ultimate Experience
Would you like a quality but inexpensive, quick setup, fast cool down, and sharp imaging telescope? Would you like to try a DIY refractor project to
get that super telescope? Then read on and see how to make a simple telescope
of refractor type.
Above you see a quality 60mm refractor telescope of the classical
What is the classic design?
The classical refractor telescope used for astronomy has a long focus 2
element objective (front lens) made of Crown and Flint
glass. The long focal length is used to reduce the chromatic dispersion
caused by refractor optics. By making the focal ratio f/15 or longer, color
dispersion is reduced to a negligible level, making the instrument perfect
for lunar, planetary, and double-star observing.
Color dispersion, or chromatic distortion, refers to the characteristic
spreading of light colors caused by prisms and lenses. If you view the bright
limb of the moon with a poor lens or a short focus refractor, likely you'll see not the bright curve of the moons limb with a black background, but rather
a bright limb that is bleeding a thin ring of colors, yellow, red, and blue. The dominance of colors is determined by the particular focus setting of the
This is caused by the color spreading characteristic of the objective
lens (or lenses). Since the colors are spread slightly by the objective,
all colors do not come to focus at the same point. So at any particular
focus setting, a narrow band of colors is properly focused, and the colors
further away in the spectrum are slightly out of focus, leading to the
halo of colors visible whenever viewing a bright target, like the limb of
the moon. It has the effect of softening the details of the image, in that
always some colors are out of focus as others are in focus.
Long ago telescope makers learned to make a telescope out of two lenses
back to back, each out of a different type of glass. Crown and Flint glass
has been and is still a common choice of glass types, though newer types
of glass with less color spreading characteristics are now used on shorter
focus telescopes. Using the two lenses together allowed telescope makers to
bring some of the color spread under better control, greatly reducing the
The second thing telescope makers learned was that long focus refractor
telescopes cause much less color spread than shorter telescopes. This is
because the angle of the focusing beam is narrower, giving greater depth of
focus. So a long focus refractor, even using the older and less expensive
Crown and Flint glasses, produces images with virtually no noticeable color
dispersion. The result, no halo of colors around bright objects, and sharper
images. The classic refractor telescope has been a refractor with an f/15
focal ratio or longer. That means that the focal length of the telescope is
15 times the diameter of the telescope.
The bigger the diameter of a telescope objective, the bigger the focal ratio
must be to achieve good color correction, if using the classic Crown and Flint
glass. Check out this Refractor
Chromatic Error vs F Ratio table to see recommendations. Referencing this
chart you can see that a 60mm of f/15 or greater is going to have very little
color dispersion. For both 60mm and 70mm telescopes, a ratio of f/12 or better
will deliver nearly chromatic-error free images.
The telescope you see above is a 60mm diameter instrument of 1000mm focal
length, having a focal ratio of f/16.7. Plenty long to have the depth of
field necessary to eliminate color dispersion. It's hard to find such long
focus telescopes in today's market. The closest complete telescope I've
found comparable to the one shown here is the Celestron
21062 AstroMaster 70 EQ Refractor Telescope, which is a 900mm focal length 70mm telescope. It
would be a good choice if after reading this article you opt out of building
your own instrument, and the Celestron is 70mm, providing greater light
gathering power at a similar focal length.
The 60mm telescope I constructed from parts is mounted on my DIY Pipe Tripod. The
homemade pipe tripod is inexpensive and easy to make, and in my case is used
to hold several different instruments, including two other refractors and my
Meade ETX90. You can save some time and still end up with a super setup by
just building your telescope and purchasing the Celestron
Heavy-Duty Altazimuth Tripod. It's an easy to use altazimuth mount that's
likely superior to what comes with most 60mm telescopes, and saves you the
hassle of building a mount like mine.
But as you might guess, I not only love astronomy and telescopes, I also
like to tinker. I'm kind of a low level amateur ATM (Amateur Telescope
Maker). If you love the astronomy and telescope part, but not so much the
tinker part, something like a ready made refractor on a computerized mount
(at a reasonable price) might be your cup of tea, like the Celestron
SkyProdigy 70 28x165 Telescope. But if you like to tinker, or want some idea
what a small refractor can do, read on.
Gather The Parts
Given that I use my trusty pipe-fitting mount as my tripod, all I needed
were the parts for the telescope. The above image shows basically all that there
is to a refractor telescope.
It shows the eyepiece end of the tube, the focuser, the finder scope, and
the telescope objective. That's about it. And if you get compatible parts,
about all you have to do is drill a few holes and screw the parts together.
I purchased all of the parts for this telescope exept the focuser from a
store on the Cloudy Nights Forum. At last check, the Cloudy Nights store
didn't seem available anymore, so you'll likely have to find a good objective
I got the focuser from Meridian Telescopes, another source that seems to
have dried up. The entire telescope project cost me only about $120.
The heart of the telescope is the object lens, which is a Japanese one of fine
quality made by the Carton company. Other sites to check out for inexpensive
telescope project parts are the SurpluShed and the eBay-Store
By compatible parts, I mean that in the example given, the telescope
tube was already the proper length, and was threaded to accept the objective
cell. The objective lens was already mounted in the cell. The focuser
already properly fit the inside diameter of the tube. I only had to drill
holes to accommodate the focuser and the finder scope.
If you must collect parts from different sources, then you'll need to be
sure of a few measurements. Be sure the lens cell fits the tube you purchase.
Be sure the focuser and finder mount fit the telescope tube size. Also,
carefully measure the focal length of the of the objective and be sure to cut
the telescope tube at a length that properly brings the image to focus within
the focuser travel range.
If you must cut a tube, it's important to cut it as square as possible.
Wrap a 2 inch or wider strip of paper around a tube where you want to cut,
making sure the ends of the paper overlap perfectly. With this strip of paper
taped into place with a bit of masking tape, use the edge of paper as a guide
to draw a line around the telescope. This will ensure that the traced line is
in fact square with the length of the tube. Then carefully cut along the line.
Cut just through the line, and rotate to an adjacent portion of the line to
continue cutting. A bit of finish up filing should leave you with a near
perfect, square cut.
Also, if your telescope tube has no baffles already in it, you'll need to
add a couple of those. This FAQ on Refractor
Baffles can help answer your questions on positioning baffles.
Add Just A Bit Of Improvising
The only part I could not readily find for my simple project was a
lens hood. Above you see my solution to that problem.
I was able to find an empty plastic soap bottle that was just bigger than
the diameter of my telescope. I cut off the neck end, and cut a hole in the
bottom to just accommodate the threads on the objective cell.
I then sprayed the inside and outside of the bottle with flat black
paint and screwed it onto the front of my telescope. It has made a fine
lens hood, cost nothing, and took little effort.
If You Can't Find Good 60mm Telescope Parts
Another option is to find a vintage Japanese 60mm telescope on Ebay,
such as the 60mm Monolux that I obtained from an online acquaintance. Then you can do as
I did with the Monolux and use it as a starting point and improve it to make
a super performer. How I did the improvements is described on the Monolux
As to new telescopes, I've heard good reviews for the long focus 60mm
telescopes from Celestron, like the Celestron
21043 60mm Equatorial PowerSeeker Telescope. They tend to be sold as kids telescopes, but an
experienced observer that I know has one of the long focus Celstron 60mm
telescopes, and gives it a thumbs up. The main problem with them is they'll
likely have inadequate mounts (tripods). There are online sites that give
suggestions on how to improve the tripods, but you may find the pipe tripod
that I use a good alternative. It is way better than the mounts
delivered with most 60mm telescopes.
Another option is to go just a bit larger and consider the
Vixen 2602 A70Lf Telescope, which is available at Amazon for less that $150, about what you
might have to pay for an Ebay 60mm quality telescope. And the Vixen is a
nice f/12.9 70mm telescope of 900mm focal length. A bit shorter than my
classic 60mm DIY instrument, which is 1000mm, but a big bigger in diameter.
That extra 10mm in diameter will increase resolution and light gathering
power in a noticeable way.
At the low price of the Vixen, it does not come with a tripod, but does
come with a dove tail to fit a standard Vixen mount. A same sized Vixen
telescope complete with mount is the
Vixen Vixen Space Eye 70 Refractor Telescope, 70, which comes in at less than $400. Makes
the old $50 pipe mount a bit more attractive, no?
A Simple Method Of Attaching The Telescope
The above view shows the business end of the telescope, with
lens hood in place. You can see from this view that the telescope is mounted
on my sturdy pipe-fitting mount.
Notice the simple attachment method used to affix the telescope to the
mount. The telescope sits on two plywood blocks with v cuts, and the blocks
are glued to a piece of plywood attached to a floor flange.
The street L shown has polished and lubricated threads and
makes the azimuth and elevation bearings for the simple tripod.
Above is shown another view of the telescope mounting block, or harness if
you prefer. Here you can easily see the plywood piece that attaches to the
floor flange of the mounting head, and the v-blocks glued to the ends of the
piece of plywood.
In this image, you can also see the simple method of attaching the
telescope to the v-block unit. A hose clamp has a 1/4 inch hole drilled
into it. A screw goes through the clamp and protrudes through the plywood.
The clamp goes around the telescope. A wing nut on the end of the 1/4 inch
screw draws the telescope tightly into the v-blocks.
By testing balance with the star diagonal and eyepiece in place, I can find
the perfect balance point and then tighten the hose clamp in place. In this
way, unscrewing a single wing nut lets me remove this telescope and mount a
different one, it also with a hose clamp at its balance point. Tighten the
wing nut, and I'm instantly ready to go with a different telescope.
Here's a drawing of the modified hose clamp. It simply has a hole drilled
through the clamp, opposite the screw mechanism. The drilled hole is 1/4
inch in diameter, enough to accommodate a 1/4 inch screw that's long enough
to extend through the wooden telescope cradle.
Pointing The Telescope
As you can see in the above illustration, the telescope is complete with a
6x30 finder, helpful for finding objects. But to further aid in the finding of
faint fuzzies (yes, you can see many such objects with a 60mm telescope), the
mount has Altazimuth setting circles. Most computer planetarium programs will
optionally list out the azimuth and elevation of any given object.
To use the circles, I must level the tripod. By that I mean the when
pointing both North/South and East/West, the telescope should be level when at
elevation zero. I place a small level on the telescope to make this adjustment,
placing shims under the telescope legs to get the level readings.
Then I point the telescope at Polaris, at which point I set the azimuth ring
to read zero. At that point my telescope is aligned, and my Xephem planetarium
program can be used to tell me the current azimuth and elevation of any desired
The display above is the night sky display from the Xephem program, available in both free and
commercial forms. This display is from the free version.
In this example, I left-clicked on an object of interest in the displayed
star chart (resized smaller for this example). This caused current positional
information for the object to be displayed in the upper-right corner, including
the object's azimuth and elevation (altitude). I've expanded that portion of
the display in the blowup. By using the Az and Alt numbers, I can
point my telescope to an object using Altazimuth setting circles. Other
computer planetarium programs, such as Stellarium and Kstars can also display
azimuth and elevation coordinate numbers.
I've also written a program for my HP128 calculator that
holds the Messier, Caldwell, and Herschel 400 catalogs, and converts the Right
Ascension and Declination of selected targets to azimuth and elevation
angles. While the calculator program offers only a text output, it does give
the convenience of needing on site only a calculator instead of a laptop
The Ultimate Pointing Aid
But now, I have a much better aid to help in pointing my telescope. It's
available for you too, freely and conveniently. Just grab your smart phone,
laptop, or Chromebook, and go to the Star Pointer web
page. There you can select objects from either the Messier, Caldwell, or
Herschel 400 target lists, and get updated pointing coordinates to all targets
in the selected list. You can choose altazimuth or equatorial coordinates, and
the equatorial coordinates (which provide an alignment procedure) will present
adjusted RA coordinates throughout the night in order to account for
earth's rotation since alignment.
The image above is an abreviated view of what the Star Pointer web page
displays. The utility can use a device's auto-location services (GPS) if
available, or if not, allow you to enter your location. The
utility needs this to compute the proper coordinates of each target for your
particular viewing position.
If you allow it to do so, the Starpointer utility saves your location in a
cookie so it will be available automatically on your next visit. That's
assuming that you observe from the same location next time. So with Star
Pointer, you don't need charts, just a smart phone and your telescope (with
setting circles). It's all I use now -- try it.
But Is All The Effort Worth It For A 60mm Telescope
I'd have to say -- absolutely. I'm in my retirement years now -- that's
right -- I'm a Stargeezer, as this
humorous t-shirt design suggests. And after years of lugging bigger telescopes
around the yard, I have to say that the incredible simplicity of using a
quality 60mm refractor on a solid mount has given me hours of enjoyment.
For quick proof of what such ans instrument can do, check out my 60mm Astrophotos for
some surprising images of the moon and Jupiter, all taken through the telescope
shown on this web page. Of course, not everyone agrees that so small a
telescope is sufficient, so let me justify my enthusiasm.
Certainly there are those (I was one) who recommend something like a 6 inch
Dobsonian telescope as a first telescope. The reasoning is that a 6 inch
aperture is enough to see a wealth of targets quite well, yet a 6 inch
Newtonian is not an expensive telescope. Newtonian telescopes have long been considered
the most bang for the buck, telescope-wise. And over the years I've
certainly owned my share of Newtonian telescopes, with two 6 inch ones in my
In fact, I started out in astronomy some 50+ years ago with Newtonian
telescopes. Like most youngsters at that time, I'd read that one needs at
least a 3 inch refractor or 6 inch reflector to do serious work, and
I could get a 6 inch reflector for about the money of a 3 inch refractor. So
in those days, I never tried a refractor of quality -- of any size.
But as I've grown older, I've found that convenience is moving up in
priority as an observing criteria. If my telescope isn't convenient, it
doesn't get used much. And it's been said many times that a big telescope that
is rarely used isn't as good as a smaller one that does get used. So, I've
started working with a couple of nice 60mm refractors to see if I'd been
missing anything, the one described on this page and my
Monolux that was
brought back from near death.
What I've been able to see with these effortless to use, ready to go at a
moments notice telescopes has really surprised and pleased me. With the two
instruments I've observed countless craters on the Moon, Jupiter, Saturn, Mars,
quite a few open clusters, and a few globular clusters and nebula. The
instruments both can perform well up to about 150x, and the Carton shown on
this page can be pushed up to 180x to 200x on bright targets while still
yielding good images in adequate seeing.
On my Telescope
magnifications of different sized telescopes, and minimum star magnitudes
observable with different sized telescopes. On my Simulated Views page you
can compare simulated views of Jupiter through different sized telescopes.
While you'll certainly find that bigger telescopes (under good conditions) can
see more, hopefully you'll also notice that what can be seen with a quality
60mm refractor is nothing to sneeze at. Especially given the cost, simplicity
and convenience of the venerable 60mm.
Photos Through My 60mm Telescope
The following photographs were all taken through the 60mm telescope
described on this page. Most were taken just by holding my digital camera
to the eyepiece. Some were taken with a Celestron NexImage web cam.
As just an example of the power of a small refractor, this picture of the
Apennines Mountains region of the moon, taken with a hand-held digital camera
through the telescope described on this web page. This isn't the best
one can do through a 60mm, but it isn't bad given the simple way the
image was taken. It shows the kind of detail one can see through a 60mm
telescope, and I can testify to the fact that the actual view through the
telescope was sharper.
Here's another lunar image taken through the Carton telescope described
on this web page. This is a view of the Plato region, with the Straight
Range also visible.
And if you happen to think that a 60mm telescope is only good for panoramic
views of the moon, think again. You can get very good close up views of the
moon as well, as the above image of the crater Copernicus reveals. It too was
taken through the telescope shown on this web page. And I must report that
while this isn't a bad photo for this size telescope, the actual view through
the instrument revealed more details than this photo has captured.
When Mars was at an apparent size of only about 12 arc-seconds, it still
gave up a few details to this 60mm wonder. I've also been able to watch Io's
shadow move across Jupiter with both of my 60mm telescopes. Admittedly, I am
generally unable to catch the Great Red Spot, but I can discern the NEB and
split the SEB, as well as see some dark regions in the NEB. In 2010, Jupiter
presented a seldom but occasionally seen phenomenon when the SEB virtually
disappeared. I managed to capture that view with the Carton 60mm on my 60mm Astrophotography
web page. For this image I didn't use a handheld camera, but the Celestron
NexImage web cam astrocamera pictured at right.
At the time of this writing, Saturn's rings are viewed nearly edge-on, so
I've not been able to try seeing the Cassini division, so hopefully I have
a treat still in store.
As to stars, refractors of this size give the nicest views of double stars
that I've seen. Yes, on nights of very good seeing my bigger reflectors can
separate closer doubles, but even then the reflectors' don't give the crisp,
satisfying images that the refractors do.
Open clusters are easy and enjoyable to see with a 60mm, and unlike my
f/5 Newtonian, stars are crisp and pinpoint right to the edge of the field
of view. Globular clusters are easily visible in my 60mm telescopes, but
most can't be resolved beyond a ghostly image.
I was surprised to see how well some nebula can be observed with 60mm
telescopes. I was able to find the Ring nebula (M 57) even when a quarter
moon was out. And on dark nights I can make out the faint Crab nebula.
Those views have whetted my appetite for more star and nebula targets.
Simplicity And Convenience
So why not just use a bigger telescope instead of trying to squeeze
performance out of a lowly 60mm?
For me it's similar to the reason I liked the QRP low-powered equipment when
I was into ham radio. Then, it was easy to sit at a microphone in Denver with a
several-hundred watt unit and chat with a fellow in Florida, but seemed more
satisfying to have done it with a telegraph key and a mere 500 milliwatts of
power. My skill at using the low power rig added to the challenge, and the
That's what I'm experiencing now in astronomy, with 60mm refractors. Sure I
can find and see targets easier with my 6 inch reflectors. But they are more of
a hassle to set up, and must cool down for at least 45 minutes before they can
deliver good views. My f/5 Newtonian on its equatorial mount is often sitting
at an odd angle for observing, so I have to loosen bolts and rotate the
telescope in its cradle to find a more comfortable position.
But my 60mm refractors (whichever one I'm using) sit mounted on my simple
but sturdy Altazimuth pipe tripod ready to go to work. They provide quality
images with just minutes of cooling. With the simple Altazimuth mount, the
finder and telescope eyepiece are always in comfortable positions as I move
from target to target. Putting up the equipment is a snap -- just put the tripod
back in the shed and cover the lenses. Done.
For casual observing, nothing could be simpler or more convenient.
One final thought.
A small telescope in dark skies can often trump a bigger telescope in
light polluted skies. It's easy to see from one to two more magnitudes of
stars in dark skies versus one's backyard. At a two magnitude difference
in darkness of skies, a 60mm in dark skies can see as well as a 6 inch
in light-polluted skies. At a one magnitude difference in sky quality,
a 60mm in dark skies can see as well as about a 90mm in light-polluted
Add to that the plethora of techniques for pushing your observing limit. For
example, be sure your eyes are dark adapted. Use the appropriate magnification
for the target. Be sure your lenses are clean, and position the telescope
behind anything that can block off a troublesome light source. Practice using
averted vision, you'll be amazed at the targets you can see with that
As one fellow that also belongs to an astronomy e-club that I frequent put
it, you can put your money into a bigger telescope, or use a quality 60mm or
70mm refractor and put you money into gas to get to a darker site.
In any event, if you haven't bought a telescope yet and aren't sure if you
want to learn about aligning and cleaning mirrors, consider starting with a
good 60mm telescope. Or, if you want to challenge your skills, try DSO hunting
with a good 60mm. Your sense of satisfaction at finding objects with such
modest equipment will surprise you.
If you observe with a 60mm or any other size telescope, consider filling out
the Amateur Astronomer
Survey. Then compare your use of telescopes and other equipment with that
of other amateur astronomers.