Grandma Moon Speaks: RMS and the Decibel

Topics Covered: Root Mean Square The Decibel Common dB Values Day has its eyes; night has its ears – Japanese Proverb In the above drawing, the numbers represent: 1. Silence 2. Audible sound 3. Atmospheric pressure 4. Sound pressure 105 Pa is the pressure at sea level, or 1 atmosphere approximately. We have already seen […]

Grandma Moon Speaks: What Influences Sound?

Topics Covered: Pressure and Temperature Pascal Threshold of Hearing Nature has give us two eyes and two ears but only one tongue – so that we should hear and see more than we speak – Socrates It is common for people to create reference standards, so that things can be measured according to these standards. […]

Grandma Moon Speaks: What is Sound?

Topics Covered: What is Sound? Speed of Sound The eyes see everything but themselves – Yugoslavian Proverb Sound is a sensation perceived by ears due to vibrations or oscillations. One big difference between sound and light is that sound needs a medium for propagation. You can’t hear anything in a vacuum, which is why you […]

Hearing vs Listening

“Okay, I’m listening.” “No, you’re not. Before I start, there’s a little chore you need to do.” “Sure, Grandma Moon.” I should have stayed in Digitown and never returned, he thought. “My cat’s stuck in the attic. Get her for me, will you?” “How did it get stuck?” “We’ll ask her when you bring her […]

The Difference between Sound and Audio

Bob hadn’t imagined in his wildest dreams that he’d sleep in Cathy’s bed, drink her mom’s iced tea and get change for his bus ride home. It was almost as if he got married. Analog Mom wasn’t amused. But she didn’t say anything. Together, they rode out to the outskirts of town, to Grandma Moon’s […]

Notes by Dr. Optoglass: Noise and Dithering

Topics Covered: What is Noise? Signal to Noise Ratio Dithering Color Banding I think television has betrayed the meaning of democratic speech, adding visual chaos to the confusion of voices. What role does silence have in all this noise? – Federico Fellini Noise is unwanted information in a signal. A fly in your soup is […]

Notes by Dr. Optoglass: Stereoscopy – Challenges in Reproducing Stereopsis in Cameras and Displays

Topics Covered: Interaxial Distance Hyper Stereo vs Macro Stereo Keystone Effect and Keystoning Stereoscopic Window In order for stereoscopic cinematography to be a creative medium it’s got to be intuitive. If it’s not in the gut, it’s not going to succeed as an art form. If you have to rely solely on tables and calculations, […]

Notes by Dr. Optoglass: Stereoscopy – Convergence and Fusion

Topics Covered: Convergence and Fusion The Singleness of Vision Taking aim for too long can ruin your eyes – Ivorian Proverb When we focus on infinity our eyes look straight on in a parallel fashion, as indicated by the red arrows. As we have already seen, optical tests on the Snellen chart are positioned at […]

Notes by Dr. Optoglass: Stereoscopy – Stereopsis, Parallax and the Inter-ocular Distance

Topics Covered: Stereopsis Parallax Inter-ocular Distance You can’t look into a bottle with both eyes at the same time – Togolese Proverb Stereopsis is the impression of depth we get when we use both eyes, assuming they have normal binocular vision. More than any other depth cue, this gives the greatest impression of space. Why? […]

Notes by Dr. Optoglass: Stereoscopy – Understanding Depth

Topics Covered: Depth and Depth Cues Monocular and Binocular Vision And so if your inclination is to champion lost causes, the case of stereo photography is readymade for you – Paul Farber So far we have treated the eye as if It were an organ capable of only two-dimensional (flat surface) vision We had only […]