Cheap Astronomy – Ancient Wisdom

A man can't stand, he can't fight. A man can't breathe, he can't fight. A man can't see, he can't fight.
-- The Karate Kid, Part III

In the matter of hand-to-hand combat (in which I have no experience, thankfully) one needs three things according to ancient wisdom:

• Being able to stand
• Being able to breathe
• Being able to see

Or maybe not ancient wisdom, this is at least according to the motion picture "The Karate Kid, Part III", which I have not seen seen (and can furthermore not vouch to its authoritativeness on the matter of hand-to-hand combat).

But it reminded me of basically three areas you need to do visual astronomy (to paint a very simplified picture):

• Optics, seeing and eyes, to be able to see
• Some sort of mount, for stability
• And "usability"

Well, the first point should be plain and obvious: if you can't see, you can't do astronomy. While the area of optical quality of the telescope is most accessible to objective measurement, it is not something that can be put into one number. There is too many things to know beyond aperture and f-ratio: MTF, contrast, stray light reduction, field of view (or rather field of view free of mechanical vignetting), chromatic aberration, spheric aberration, coma, astigmatism, field curvature, distoration, RMS wavefront error, Strehl ratio, and so on. (And that is not accounting for tolerances and errors during production…) But at least one can try to get a measured idea of what to expect from a scope.

Another point not on the radar for beginners: To be able to see is more than just the quality of "optical tube assembly" (and more than the combination of OTA with eyepieces). Unfortunately this is a topic of its own.

The second point is usually overlooked as well by inexperience beginners (and exploited by the industry sell them undersized mounts): One is using high magnifications and any shaking caused by a mount will make it hard (if not impossible) to use an astronomical telescope. There is the measure of maximum telescope weight supported by an mount, but (beyond the question of how this is measured) this is not a simple number or measurement: A long telescope will put more strain on a mount than a short telescope with the same weight. Person A is more tolerant to shaking than person B. And so on. But it stands: The more stable a mount, the more enjoyable a view through a scope.

And while the third point seems simple (to the point of being a tautology), it is the hardest to grasp: If an telescope setup lacks usability, it is not usable. If you can't find things in the night sky with it, what good is a telescope? What good is a telescope and mount, if it is so heavy that you rather leave it at home than drag it with you? What good are high magnifications if the focuser shifting is so bad that you can't actually reach focus?

Now if it were just "Good, But Expensive Astronomy" I'm after, I would recommend the best setup that money can buy (and there are some out there).  Some of these question can be solved by throwing money at them. But only up to a point.

If you want to do astronomy, you have to invest time, acquire knowledge and skills – just like any other hobby, just like a craft or a sport. Sure you can have fun just "dabbling" in astronomy, but for me the fun in is improving, advancing, progressing.



And for me it is "Cheap Astronomy" I'm after, or rather affordable astronomy, with a good ratio of cost to optical quality, stability and usability. With some some measured modifications. Investing time to save money and gain knowledge.

More to follow.