Welcome to the ARO! 

On this website I have documented all my activities as an urban astronomer.  My main focus has been on astronomical filters, researching and testing them to better understand how they work.  Follow the links below to learn about what I've been doing in each of the categories.  For more about myself read below.



   What's New?: 
  • Dec. 6th, 2023 - Uploaded links to 3 new presentations, 2 new magazine articles, and 6 new test reports.
  • May 11th, 2023 - Uploaded a couple of new test reports and magazine articles.
  • Oct. 31st, 2022 - Upload batch of new test reports:  revised ALP-T test, narrowband H-alpha test, SHO filter set test, solar camera test, spectrometer accuracy report, & 3nm multi-narrowband filter test.
  • Feb. 22nd, 2022 - Revamp homepage to be more relevant and up to date.


Astronomical Filters
Test Reports Technical Papers Magazine Articles Presentations
  Original 2010 Web-Paper "Introduction to Astronomical Filters"
Chapter 1  "Introduction"
Chapter 2  "The Human Eye"
Chapter 3  "Planetary (Colour) Filter Research"
Chapter 4  "Using Planetary (Colour) Filters"
Chapter 5  "Deep-sky (Band Pass) Filter Research"
Chapter 6  "Using Deep-sky (Band Pass) Filters"
Chapter 7  "References"
EAA Albums on FLICKR Moon Phase Image Project
Older Video Astronomy Messier Images Older Misc. Deepsky Object Images
2012 Venus Transit Comet ISON Video From SOHO Pics
Old Paper Logbook Excerpts Astro Related Pics 2009-2010
Miscellaneous Topics
Test Reports Technical Papers
Magazine Articles Presentations
EAA Camera Test Project My First Astro-Video Cameras
Pier Build & Atlas Mount Refurb Meade standard field tripod mod
Meade standard wedge mod Meade LX10 OTA & drive mod
80mm wide FOV refractor build Short focus star diagonal mod
Blog About My Equipment 2009-2011 Reference Material
International Astronomy Day Ottawa
virtual IAD 2020 virtual IAD 2021
free handouts  
Royal Astronomical Society of Canada (RASC) - Ottawa Ottawa Valley Astronomy & Observers Group (OAOG)


Who is the ARO?

Hi, and welcome to my website.  My name is Jim Thompson, and I'm an Aerospace Engineer working and living in Ottawa, Ontario, Canada.  I've created this site to document my journey into and through the field of amateur astronomy.  As a boy growing up in south-eastern Ontario I was an avid fan of star gazing.  Even then I would set my alarm and get up in the wee hours of the morning just to see the Perseids at their peek, or catch a glimpse of Orion's belt.  As I got older however, grown-up distractions like university, work, and family pushed astronomy to the side.  Now that I'm in my 50's, I have rekindled my interest in astronomy after its >20 year hiatus, inspired to a large extent by my kids.  Living in a large city has presented many challenges to my astronomy hobby, what with the severe light pollution.  This impediment combined with my engineering curiosity is what has driven me to become somewhat of an expert on astronomical filters.


Last updated: 25-May-24

Copyrights to all content from the webpages hosted here belongs to Jim Thompson. 2009-2024.