Photographs of My Telescopes

Kokusai Kohki's Magellan F4.8 (Later models F4)
This 32-cm Dobsonian telescope is my main observing instrument.
I bought this telescope in December 1995 and have made some
improvements since.

There are five reasons why I chose this telescope:
1. A very good price.
2. A carrying handle is attached to the telescope tube. This is quite
handy.
3. The focuser accepts two-inch eyepieces. A big advantage.
4. The ground board has short wooden feet with pointed tips.
5. The primary mirror cell has ventilating holes.

A counter weight is added. If a finderscope is attached, the
balancing is a problem without a weight.
I made a dust cover from cardboard. (Later models seem to come
with a dust cover.)


I made a dust cover from cardboard. (Later models
seem to come with a dust cover.)


Finder telescope
I used a Telrad at first but found it not adequate for
faint objects. I replaced it with a 30mm finder
telescope with a 45-degree correct-image prism.
This 45-degree prism is quite handy, as the
telescope's focuser is attached on the right-side of
the telescope tube. The image through the finder
is excellent. The eyepiece is replaced with a 32mm
eyepiece with crosshairs. An aperture of 50mm is
generally said to be needed for a telescope of this
aperture, but I am happy with a 30mm lens. Although
I have never used a 50mm finder, a smaller aperture
would be easier, as you will not be confused with too
many faint stars in the field. The white tube is an
improvised dew cap made of a container for potato
chips. It is very effective and I have never had any problem with dews. It also helps to keep the tube in balance.

This is a view of the inside of the tube. As the
original black paint was not very effective, I glued
velvet sheets, instead.
I believe it is sufficiently effective, although I couldn't
made a "before/after" comparison. I also marked a
dot at the center of the mirror for collimation.
The secondary mirror is fairly
small. I don't think the accuracy of the mirror
surface is particularly good, but sufficient for
observing clusters and nebulae. I am happy with the
mounting as well.

I added a fan to reduce tube currents and found it
very effective. Even on nights under unfavorable
conditions, I can
enjoy observing deep-sky objects with minimal
waiting. Without the fan stars are rather fuzzy at
110x, but once it is turned on, the image becomes
sharper.
Push-pull bolts for alignment are visible. They are
very easy to use. I transport the telescope lying
on its side, but it does not need realignment as
long as I don't go beyond 200x, which israrely used.

What's the shortcoming of this telescope? It is the focusing
mechanism. It uses a helical focuser but the pitch is too fine.
It is also difficult to rotate
it. I replaced it with my own invention using a 2-inch focuser
tube one end of which is threaded. A helical S-type focuser
is partially inserted into this.
It works extremely well.

These are the eyepieces I own.
I have a binocular viewer for the Dobsonian
telescope. It is easy to use but I notice the
image is a little degraded. These days it
is mainly used for viewing the moon. Since I
bought the viewer,
I have been observing the moon far more often.
The image of the moon through the viewer is
superb. Using just one eye to observe the moon
gives me a headache, but with this binocular
viewers it is easy on your eyes.



Detail of the mirror and mirror cell
The mirror cell is held by coil springs,
which makes collimation easy. You
can see the mirror taped to the cell
not to distort the mirror. I don't know
how the mirror and the cell are in
contact, but the system does not
seem to be good for temperature
adaptation.








This is to show how dirty the mirror
is. It is even moldy. But this does
not seem to affect the image.
I cleaned it after taking this photo to
avoid embarrassment. It needs
cleaning after one year's use in a
poor storage condition.









Ninja-500 Dobsonian telescope.
The usual 30mm finder is attached. (I believe the
best finder is the one you are most used to.) A PVC
pipe is attached where a finder should be normally
mounted. It is used to bring a star to the finderscope
field where star-hopping starts.




This is how Ninja-500 is
transported.




In the passenger-side seat
accessories and ladder are loaded.