Notes by Dr. Optoglass: Camera Exposure

Topics Covered: Exposure and Camera Exposure Exposure Value (EV) and Stops F-number and Shutter speeds Look and think before opening the shutter. The heart and mind are the true lens of the camera – Yousuf Karsh This is how a camera works: The sensor is a jar that can take in light till a certain […]

Notes by Dr. Optoglass: The Units of Photometry – Part II

Topics Covered: Nits and Lux Footcandles and footlamberts Typical light levels for various scenarios Actually, I’m not all that interested in the subject of photography. Once the picture is in the box, I’m not all that interested in what happens next. Hunters, after all, aren’t cooks – Henri Cartier-Bresson In part I we covered measuring […]

Notes by Dr. Optoglass: The Units of Photometry – Part I

Topics Covered: Joules and Watts Lumens and Candelas Lumens per Watt Counting Photons A beautiful thing never gives so much pain as does failing to hear and see it – Michelangelo Let’s start with some radiometry units: Imagine a light bulb has having a total volume (energy) of light that it can pour out during […]

Notes by Dr. Optoglass: How to Measure Light

Topics Covered: How Light Works Radiometry vs Photometry What is Brightness Light makes photography. Embrace light. Admire it. Love it. But above all, know light. Know it for all you are worth, and you will know the key to photography – George Eastman The full spectrum of light is represented thus: As you can see, […]

Notes by Dr. Optoglass: The Megapixel Counts of the Human Eye

Topics Covered: The Megapixel Count of the Human Eye Rule of Thirds? Whenever I arrive on a real location, I have to move around and work out what the best angles are going to be. When I was moving around with the lens, I discovered things that the naked eye would not have – Pedro […]

Notes by Dr. Optoglass: Airy Disk and Pixel Density of the Human Eye

Topics Covered: The Airy Disk Diffraction Pixel size of the Eye Pixel density or resolution of the Eye Everybody thinks they know what art should be. But very few of them have the sense that is necessary to experience painting, that is the sense of sight, that sees colors and forms as living reality in […]

Notes by Dr. Optoglass: The Resolution of the Human Eye

Topics Covered: The average and maximum resolutions of the human eye PPI and DPI at various distances Beauty is all very well at first sight; but who ever looks at it when it has been in the house three days? – George Bernard Shaw Exclusive Bonus: Download my free cheatsheet (with examples) of the most […]

Notes by Dr. Optoglass: Focal Lengths of the Human Eye

Topics Covered: The many focal lengths of the eye The focal length of the eye in photographical terms Nature will bear the closest inspection. She invites us to lay our eye level with her smallest leaf, and take an insect view of its plain – Henry David Thoreau Before you get the wrong impression, let’s […]

Notes by Dr. Optoglass: Angle of View and Aspect Ratio

Topics Covered: The Angle of View of the Eye The Sensor Size of the Eye The Aspect Ratio of the Eye The Crop Factor (35mm equivalent) of the Eye The eye of the master will do more work than both his hands – Benjamin Franklin Put together, the horizontal angle of view of both eyes […]

Notes by Dr. Optoglass: Eye Geometry

Topics Covered: The Emsley model of the Eye The Focal Length the Eye The Total Retinal Area of the Eye The health of the eye seems to demand a horizon. We are never tired, so long as we can see far enough – Ralph Waldo Emerson The problem with drawing the geometry of the human […]