Wednesday, November 18, 2020

Looking for a Telescope as a Christmas/Hannukah/Kwanzaa Gift?

 I purchased this Meade 80mm refractor as a starting telescope for my grandkids, who have shown some interest.

I have not used it for astronomy yet (continual cloud cover), but for terrestrial use it is very satisfying. Images are sharp even with the shortest and therefore most powerful eyepiece. The instructions are aimed at an adult or a very smart tween (this describes my granddaughter), and they are very clear although I was almost done putting it together before I needed them. The alt-azimuth mount is among the simplest and most intuitive that I have seen. Other reviewers have been disappointed by plastic knobs. Were I feeling ambitious, I would machine replacements of aluminum. But at this price, it is fine.

The weak point on all introductory telescopes are the eyepieces. This is no exception. The eyepieces are sharp and clear, but dropping some of my higher end orthoscopic eyepieces in shows that the included eyepieces are not quite as sharp, and are definitely narrower apparent field. If this is a first telescope for a budding astronomer, or just a first telescope for you, they are just fine. I will report back with Moon photographs when the sky clears.

A nice touch was that the diagonal has a sheet of glass protecting the mirror from dirt. Among the most annoying issues with diagonals is how hard it is to clean them when they get dirt on them. 

Clear night last night.  The Moon was glorious at 15x, and 44x.  Saturn's rings were just barely visible at 67x.  Jupiter's big satellites were visible at 15x and at 44x, my wife could see cloud bands.  (My eyesight even corrected is not as good as hers.)  At 67x, chromatic aberration (purple and green edges) were an annoyance on Jupiter.  On a bright object this problem with an f/5 achromat is unavoidable.  That's why apochromats sell at 4x-6x the price.

3 comments:

Jim Horn said...

Clayton, these 80mm f/5 telescopes have been very popular for a few decades, sometimes known as "Short Tube 80s". In the heyday of Yahoo Groups, the Short Tube 80 group had nearly a thousand active members with loads of messages on their use, modifications, accessories, etc. My wife sold a collectible Beanie Baby Buddy to buy me one in 1999 and it has had a lot of use since. Being a perfect grab-and-go telescope, it has had much more use than my 10 inch f/6.5 Dobsonian despite the latter's far higher performance.

I highly recommend a 45 degree erect image diagonal for day time spotting scope use. A 32mm wide field eyepiece gives terrific views with lots of eye relief for eyeglass wearers and use with the 2x Barlow gives a good range of magnifications without diffraction limit problems.

Best to you and your grandkids!

tkc said...

What would one expect to be able to see with the Meade 80mm.
Assume the following:
A clear night.
No moon.
Little local light pollution.

What should I expect looking at the following:
The Moon
Mars
Jupiter
Saturn
Andromeda

Clayton Cramer said...

tkc: I expect to do astro testing tomorrow night. Based on aperture and apparent optical quality: Moon will knock your socks off. Mars will be an orange dot. Jupiter will show the four big satellites and possibly cloud bands. Saturn I expect rings will be visible although not large. Andromeda should show an expanded fuzzy except under VERY clear, calm skies. The 100mm version will do all those and better.