What telescope universe do you live in?

[Mark Wagner]

I was playing around on AI last night, and began asking questions regarding the sizes of telescopes owned, where most ownership exists, and more.  The results were quite interesting.

Sizes owned in percentages:

76–114 mm (3–4.5") 20–25%
130 mm (5") 20–25%
150 mm (6") 20–25%
200 mm (8") 20–25%
250 mm (10") 5–10%
300 mm (12") 2–4%
350 mm (14") <1%
400 mm (16") <0.5%
450 mm (18") <0.2%
500 mm+ (20"+) Well under 0.1%

I own two in the bottom (least owned) 11%.  I own two in the top 85%. I own none in the top 40-50%.

Sky and Telescope subscriber base (worldwide) as one possible indicator of amateur astronomy's "reach" is also interesting, about 55K-60K (this of course leaves out online).  So  S&T subscribers with 500mm+ telescopes is theoretically well under 60 subscribers. Fewer amateur astronomers appear to be club members (in the US) than there are S&T subscribers.  It would be interesting to test that 500mm+ "60" result, just among TACos to see if it seems realistic.

The "active" (serious) consumer market worldwide is roughly 100,000 to 500,000 if all these AI results are within reason.

This is just a taste of the very curious results.  We here may exist in a telescope bubble universe.

Can you (without querying it) guess the top five city locations for 16" or larger owner in the US?

[Richard Navarrete]

Your percentages are confusing to my morning brain. Which scopes are you calling top 40-50% and top 75%?

Richard

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[Mark Wagner]

Top 40-50% are my 6" and 8".  Add in the 10" and (you're right about my numbers) it becomes 60%.  Top of the list.

I own one (18") near the bottom of the list:  <0.2% of the ownership market.

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[Mark]

Interestingly, I asked a specific this morning.  Thinking of Akarsh's 28 and that Bob Douglas until recently had one, I queried how many 28" and over telescopes were owned worldwide.  The result was for telescopes from 28 to 50" and over - estimating 1,000 total.  Jimi Lowrey at 48" is part of a 20-80 telescopes owned in the 40"-48" class worldwide.  More in that class than I'd guessed.

[Paresh Khanapurkar]

My guess (without a query) on the top five "locations" for 16" or larger owner in the US

SF Bay

SoCal

DFW

FL

NE

80% of my collection is in the top 80% (Orion ST80 / ST120 / XT8i and TV NP101is); additionally I do have a spot in the top <0.3% - an Obsession 18UC

[Richard Navarrete]

Interesting , although different brands, I have a similar collection.

AstroTech 80mm refractor

ED 102

ED 127

ST 120

8” dob

8” SCT

10” dob 

18” Obsession Classic

All of ‘em get used!

Richard

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[Mark Wagner]

Paresh - you have a "close enough for partial points" on two locations, but not exact.  So "1" point.  Better than what I'd guess.

Anyone else, without cheating?

[David Kirjassoff]

What happened to your AT 72?

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On Jul 3, 2026, at 12:16 PM, 'Richard Navarrete' via The Astronomy Connection (TAC) <sf-ba...@googlegroups.com> wrote:

 Interesting , although different brands, I have a similar collection.

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[Richard Navarrete]

I never had a 72, just the 80.

Richard

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[Paresh Khanapurkar]

Ha Ha Mark - I'll take 1 over zero...

Give us the answer soon...

[Mark Wagner]

Sure.... top five cities

1. San Diego
2.  Tucson
3.  San Jose
4.  Phoenix
5.  Los Angeles

The SW US is king of amateur astronomy!

[Tan usa1]

Well the telescopes the most for Visual (actually more than astrophotography on somemonths) are

1. 30" Challenger

2. 11" Celestron

Now only if they could switch off the lights in Salinas and stuff :)

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[Mark Wagner]

Tan,

I've used the 30" Challenger before.  I almost signed up again recently.  But th LP is prevalent , and discussing with Rob Hawley I suggested it's a beast to move around, he replied (paraphrased) that it's putting it mildly.

I'm not so interested in an evening workout doing astro.  YMMV.

[Paresh Khanapurkar]

Gosh! Darn it... how did I miss AZ???

I completely agree that in Continuous 48 nothing can beat SW USA!