8-inch F/6 Further Correction and Testing

Sharing further updates about the correction and testing of my 8 inch F/6. In the below video, You can see the center is still slightly deep. There is a ridge around it that appeared during the correction and is now at the same level as the outer zone. I expect the next few correcting sessions

Toughened/Tempered vs Plain/Plate Glass

In one of the recent discussions in the Indian ATMs WhatsApp group, there was a discussion about using the plate or toughened glass as a mirror blank. So in this post, I am putting forward my thoughts and how you can check whether a glass is toughened/tempered or not. A disclaimer though, I have personally