Sky and Telescope
||50mm achromatic refractor operating at
Large 150mm achromatic refractor that ships with a 25mm Plossl eyepiece, 2x
Barlow lens, 9x50 finder, mirror diagonal, and a CG5 equatorial mount with an
As a new member, I thought I would chime in on this group. I use a
Skywatcher 150mm Refractor. Since I got it in April, my longtime friend an 8" Schmidt doesn't get used anymore. This is one good scope
for the money as it star tests between 1/6-1/8 wave under-correction. There are no zones to speak of. My useful magnifications range from
30x-350x with up to 428x sometimes on the Moon.
Collimation of the objective, focuser and star diagonal is critical for good images. My scope needed to be adjusted with all these things
collimated as an integrated unit. I assume most if not all of these scopes are
I have a lot of high end accessories, (diagonal, eyepieces, etc.), so I won't comment on the ones included with the scope. I made tripod legs
out of 2"x4"s, trust me you will need heavy duty legs.
This scope just crushes the my 8" on lunar/planetary images. Last Friday and Saturday, Mars views looked very much like the center
photos in the July Astronomy Magazine on page 53! Now that's good! I used magnifications of 130x-230x, no color filters and used the
scope's dew cap/aperture stop of 4 1/4". This gave the scope a focal ratio of f/11 and almost got rid of chromatic
aberrations while giving longer durations of good seeing. At the astro club get-together, this
set-up gave the best views of Mars and there were some really good scopes ($$$) there. At full aperture, its still great, it just shows a
higher degree of chromatic aberrations (still very well suppressed). Keep in mind the Celestron version of this scope currently goes for
about $800 with mounting.
On DSOs this scope really shines giving great views of many objects that are comparable to larger scopes. The bigger scopes do show
brighter images, but they are not that much more detailed. Also, the 12000mm focal length can allow for a very large FOV with my TeleVue
2" 40mm EP.
Globular clusters show up great, but aperture usually wins on these. Compared to an 8" Schmidt, this refractor gives up very little. It
probably has to do with a refractor's ability to focus stars down to a smaller spot size. Generally, SCTs have more bloated star images.
Surprisingly, this scope really shines on galaxies. I think a 12" is only getting a little better as far as these objects can be seen with
detail. Apertures of 16"- 18" starts to show apparent spiral
structures. The 6" aperture combined with higher contrast is a good combination for great images. Additionally, its portable.
I could go on, but as a general purpose scope for visual astronomy, this one is hard to beat and you could still drive the Toyota to the
mountains and make the mortgage payment.
Submitted by Sol Robbins - firstname.lastname@example.org