2: Fundamental Components Flashcards
Explain photons:
Waves of energy that perform like particles.
Can polarizing light sources prevent diffusion?
No but they can reduce some elements that contribute to glare.
Describe the main principle of Inverse Square Law.. (related to visual)
Intensity of the light decreases as the distance from source increases.
Our eyes cannot perceive all colours between this range equally…
400 nm to 700 nm (nanometers)
Tone/Hue:
Length of wavelength.
Saturation:
Purity/mix of colours.
Brightness:
Intensity or “pops”
Reflection:
Light bouncing off the surface.
As reflection increases, absorption decreases.
How can you reduce glare?
Polarizing lenses or filters.
Light intensity is critical to create what?
Contrast
When considering lighting for an inspection, which 2 laws should you consider?
Inverse Square Law and Lambert’s Cosine Law.
What are the fundamental particles of light?
Photons
Our brain perceives the colour black when…
No electromagnetic waves in the visible portion of the spectrum can reach our eyes
Contrast:
Difference in the colour/brightness of objects within our field of view
One of the first principles of a good visual inspection is creating conditions that maximize what?
Contrast
What happens when aluminum cracks?
Can create dark coloured oxide particles that stand out against the shiny aluminum
Any major change in the lighting system, such as addition of filters, typically require a repeat of what step?
Measuring the light intensity
When you double the distance from the source, you decrease the intensity by what?
1/4 the original
The formula used for Inverse Square Law is:
S.I. = I/D squared
What do each elements of the formula mean?
S.I. = surface intensity I = original light intensity D = proportional increase in distance (new distance divided by original distance)
Light intensity is ultimately a function of what?
Density - the more light photons that strike a surface in a given area, the more intense the light
Lambert’s Cosine Law is similar to the Inverse Square Law BUT it also compensated for what?
Photons of light that strike the surface at an angle
The eye filters, focuses and converts light into…
Electrical impulses that the brain interprets
The cornea refracts light onto the lens, the lens refracts light onto the retina.. this double refraction causes images to appear:
Reversed and upside down on the retina, then turned right side up by the brain
Which part of the brain corrects the images that are projected onto the retina?
Occipital lobe
What is the shape of the eye for someone who is nearsighted?
Longer from front to back (makes projected images not quite reach the focal point)
What is the shape of the eye for people who are far sighted?
Length of the eye is too short (making the images project PAST the focal point)