The Quest for Aperture: Why Are Big Telescopes Better? | 2024-07-07

We all know that bigger telescopes can produce sharper images and produce more signal, but do you know why? We’ll start with a look at optical resolution and how the atmosphere affects image sharpness. Then brace yourself for a little math as we go through the radiometry of imaging for both extended objects and point sources. The result will be a better understanding of how aperture, focal ratio and sensor size interact to produce the signal measured by your camera. In the end, we’ll look at some examples and you’ll leave with a better understanding of what large telescopes are good for and why they are so desirable.
Dr. John Hayes is a retired engineer, entrepreneur, and research professor with degrees in physics, astronomy, and optics from the University of Arizona. In his working life, John developed systems for testing optics, disk drive components, and many of the world’s largest telescope components including the JWST. He has authored over 30 professional papers, articles, book chapters, and presentations and he holds 14 patents in the fields of optics and atomic force microscopy. In retirement, John has returned to the hobby of astro-imaging. He currently operates a small, wide-field refractor and a 600mm telescope both located at Obstech in Chile.
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[@dmccallie]

Wow. Now I know how little I know about this hobby. :)

[@EH-pm1ke]

Favorite guest, I always learn a lot when John gives a talk!

[@sjpp71]

Excellent presentation! Interesting technical details to take in. Thank you Dr Hayes for giving us the "excuse" to get bigger telescopes!

[@tostativerdk]

Really excellent presentation of topic that can be quite confusing. Thanks for sharing :)

[@TAIC]

Glad you enjoyed it!

[@terrizittritsch745]

Great show, thanks so much! Lots of great and practically useful information.

[@stefanrbenz]

Thank you for this great presentation!
Are the presentation slides available for download somewhere?

[@TAIC]

Sorry, but no, John's slides are not publicly available.

[@anata5127]

Excellent theoretical presentation.
Rest ….
Why should I get a big telescope?” ‘Cause I have a lots of money.

[@thierrymartin8378]

Nothing about the baffle size. This is very critical for what you are expected from a telescope. You can loose 30% of the energy without considering central obstruction.

[@davidemancini7853]

Nice one, but I have not found anyone who explains how to self measure seen…

[@MatthewHolevinski]

Wives listen to objective data? My god you guys are hippies :) 🤭😶‍🌫