Saturday, November 13, 2021

Book Review: The Science and Art of Using Telescopes

The essence of the book is given in the opening. Get past the beginner stage by finding new interests; specialize in subbranches of observational astronomy (page 2; page 4). After that, the writing devolves into a rambling monologue directed at knowledgeable amateurs. The information provided serves more as reminders of what we know, rather than providing new learning or directing us to important resources. Early on and throughout, the author tells us to find out about the current markets for instruments and accessories by referring to “monthly magazines” none of which he names. In point of fact, Popular Astronomy from the SPA appears bi-monthly, and the independent Amateur Astronomy comes out quarterly. The book offers no suggestions for websites, discussion boards, chatrooms such as Facebook and Reddit, or other online social media.

Author Philip Pugh does name his favorite brand of equipment, Sky-Watcher. He cites them 16 times (as “Skywatcher”), which is as often as he cites Meade (7), Celestron (6), Takahashi (2), Astro-Physics (1) , and Tele Vue (1) combined. Other labels are similarly passed over with brief mentions. 

The Science and Art of Using Telescopes
by Philip Pugh, Springer, 2009.
 

The references to Astro-Physics and Tele Vue underscore the fact that this book is poorly edited. The brand names are misspelled as Astro Physics (page 250) and indexed as Astro physics; and Televue. Takahashi is misspelled as Takashi (page 28) and Takahasi (page 250). Plossl (never, as proper, Plössl or Ploessl) appears in the index as two lists: Plossl and Plossl eyepiece

 

Those small errors reveal the lack of professional proofreading. That speaks to the painfully obvious fact that this book reads like a first draft. The author loves (even in parenthetical comments!) exclamation points! Pugh just wrote this off the top of his head and Springer accepted it uncritically.

 

As an indication that the author did not have his manuscript fact-checked by an independent reader or even check his own work, the definition of ED (extra-low dispersion glass) is wrong, and wrongly stated. He calls ED “extra dispersion” throughout the book, and in the Glossary: “An extra dispersion lens is an improvement in the achromatic objective lens theme where it uses extra dispersion flint glass to improve performance.” (page 368). 

ED Extra-low dispersion


"Nikon's original ED (Extra-low Dispersion) glass lenses effectively compensate for color fringing especially at high magnification." -- https://imaging.nikon.com/lineup/sportoptics/how_to/guide/fieldscopes/choosing/choosing_03.htm


"ED stands for "extra-low dispersion," which refers to the composition and optical properties of the glass used for the lenses.  ED glass is specially formulated and contains rare-earth compounds that greatly reduce a visual defect called chromatic aberration." -- https://www.celestron.com/pages/ed-glass


ED glass enhances apochromatic lens design by producing extra-low dispersion of the wavelengths of light passing through it thereby giving an even better apochromatic performance.  -- https://explorescientificusa.com/collections/apo-triplet


In this chart, standard glass is shown on the far left. To the right of it are two commonly used extra low dispersion (ED) glasses. -- https://www.stellarvue.com/optical-glass-types/

Perhaps the hallmark of his style is that he avoids unequivocal statements. Pugh cannot discuss telescopes (pages 6-8) without digressing to his preferred choices among binoculars, even though “Choosing Binoculars” is the next section after “Choosing a Telescope.” Paradoxically, that section is not at all about choosing a single telescope but argues very well that you need more than one. The author’s apparent fear of absolute statements results in meaningless advice. “While it is true that the Usual Suspects (see the appendix) can sometimes look better under clear conditions, some gems such as M81 in its full glory have to be enjoyed while the chance is there.” (page 41). That sounds like good advice: whatever your skies right now, take the opportunity to view what you can. But if you read the words carefully, Pugh is saying that M81 can be seen in its full glory even though not under clear conditions, which contradicts the opening clause. 

 

That example is from the section “Too Cloudy to Go Out?” (page 40-41) which is about why is it not really too cloudy to go out because telescopes can often cut through poor seeing conditions. Faint clusters, dim companion stars, and more can all be viewed under bad conditions. I get the point, but an editor would have retitled the heading. 

 

Aversion to unequivocal assertions delivers many instances of “however.”  

“Unguided exposures at long focal lengths can be troublesome on some mounts because of tracking errors. However, you will find that auto-guiding can compensate for this very well. Celestron offers a version of this mount. Moving up in quality and performance, companies such as Astro Physics, Takahasi [sic], and Software Bisque manufacture excellent mounts. However, considering the typical cost, they are not mounts for a beginner!” (page 250). 

Why are such mounts not suitable for a beginner who can afford them? He never says. 


It is disappointing in a book that recommends finding new interests that the author provided no pointers to the organizations that support the many sub-branches of observational astronomy and citizen science. On page 114, the author discusses occultations but only someone who knows the hobby well would know about the International Occultation Timing Association (IOTA) or the fact the the Society for Popular Astronomy has an Occultation section and that the chair of that committee will generate a spreadsheet for you of occultations predicted for your location. Similarly, for lunar, solar, and planetary viewing (Chapters 2, 3, 4), the Association of Lunar and Planetary Observers (ALPO) was founded in 1947 for amateurs, and the American Astronomical Society (open to amateurs) also has its Division for Planetary Sciences. For deep sky viewing, AAVSO (the American Association of Variable Star Observers) maintains a peer-reviewed archive of data, much of it provided by amateurs.


PREVIOUSLY ON NECESSARY FACTS

Seeing in the Dark: Your Front Row Seat to the Universe

Turn Left at Orion

Michael Shermer's Moral Arc

The Science of Liberty


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