My first Magazine Sky & Telescope - 04.2019 | Page 70

TELESCOPE CARE
by Jerry Oltion
Nurture
YOUR
NEWT II:
Collimation
Aligning your reflector’s mirrors —
critical to getting the best view —
is easier than you think.
I
n our fi rst installment of this series, we talked about
keeping your Newtonian telescope clean and how to
wash the primary mirror when it gets dirty. Now let’s
look at how to collimate it.
Like mirror washing, collimation is a lot easier than
many people think. The Internet is so full of scary advice
on collimation that many people think it’s as dangerous
Figure 2
Spider vane
Reflection of
secondary
mirror
Edge of primary
mirror with mirror
clip visible
Center marker
on primary
mirror
p OUT OF WHACK You’ll see something like this when neither the
primary nor the secondary mirror is aimed properly. Each illustration
depicts the telescope pointing straight up.
68
A PR I L 2 019 • SK Y & TELESCOPE
p SECONDARY ALIGNED When the secondary is adjusted prop-
erly, the entire primary will be visible within its perimeter. Note that
all three mirror clips are equally visible.
COURTESY
PHOTO:
Figure 1