Product Catalog
An astrophotograph and a look through a telescope both inspire wonder. But in different
ways. Due to the natural limitations of the human eye, a long-exposure astrophotograph of
the Great Orion Nebula (m42) will be infinitely more detailed and colorful than what you can
possibly see through the telescope’s eyepiece.
Despite this truth, no photograph can compare with the experience of standing under a clear
sky and looking into the heart of a star factory 1,500 light years away with your own eyes. After
all, you are witnessing creation. It’s sort of like comparing a photo of the Grand Canyon to
actually going there.
Depending on the steadiness of the atmosphere, the darkness of your location, and how dark-
adapted your eyes are, a large scope will turn distant galaxies, star clusters, nebulas and
planets into truly magnificent sights you will never forget.
The larger the aperture, the brighter and higher resolution your image.
Aperture is about gathering light. Period. The human eye can only gather as much light as can squeeze through
the pupil of your eye. Not much. So the real purpose of a telescope is not magnication—it’s gathering more
light. The bigger the aperture, the brighter the image. You won’t enjoy looking at a dim object, no matter
how big you make it. That’s why any experienced astronomer will tell you aperture is everything.
As a general rule, an 8-inch telescope has four times the light gathering power of a 4-inch telescope. The
photo-illustrations on this page were created to simulate the view through telescopes of dierent apertures
at the same magnication. Examine them and it’s easy to see why bigger is better.
The main caveat to the “bigger is better” rule is portability. Telescopes above 10" become increasingly more
dicult to transport to your favorite dark sky location (not an issue if you plan on a home observatory or
roll-o shed).
But the best scope for you is the one you will actually use. Most amateurs consider an 8" scope the perfect
compromise between brightness and portability.
a s t r o p h o t o g r a p h y : j a s o n w a r e / m 4 2 - g r e a t o r i o n n e b u l a / l x 4 0 0
10" 12" 14" 16"
Understanding
Aperture
EXHIBIT 4