[pmrid (Peter)]

I’m curious! Why are ccd sensors described as “1””? For example, the ASI533 MC is a 9MP SENSOR IN A 11.3 x 11.3 square array (3008x3008) with a diagonal of just under 16mm.

What makes it a 1inch sensor. That’s how ASI describes i. See their blurb at https://astronomy-imaging-camera.com...33mc-pro-color