Unit Review Questions Flashcards
What is radiant energy?
Any form of energy radiating from a source.
Wavelength is measured by the:
Distance between corresponding parts of two consecutive waves.
The number of waves that pass a fixed point in a given unit of time is called:
Frequency
What is another word for frequency?
Hertz
Which part of the electromagnetic spectrum can be observed by the human eye?
400-700 nanometers
Which color of light do you see when viewing the entire range of wavelengths in the visible spectrum at one time?
Red
What do we call the bending of light rays?
Refraction
Dispersion is defined as the:
Separation of white light into its constituent colors.
Light that is made to vibrate in only one plane is:
Polarized
If Kelvin temperature registers at 5,500 K, which color of light is dominant?
Blue
Which temperature reading is the approximate color temperature of fluorescent light?
4,800 K
How is hard light characterized?
Intense, directional, creating harsh shadows.
When light reflects from a point on an object through the lens, the distance (between the point and the object) at which the rays of light are considered parallel is called:
Infinity
Which two factors determine lens speed?
Focal length of the lens and diameter of the aperture opening.
When the f/stop decreases from f/16 to f/8, the amount of light reaching the focal plane at f/8 is:
Four times as much
Hyperfocal distance of a camera lens is the distance:
From the optical center of a lens to the nearest point in focus when the lens is focused on infinity.
Which two factors may vary the hyperfocal distance of a camera lens?
Focal length and aperture
Which procedure will increase the depth of field for a lens?
Closing down one f/stop
The ability of a photographic lens or material to reproduce fine detail is called:
Focus
Photographing a test pattern at a greatly reduced scale and then examining the image under adequate magnification is the normal method of measuring:
Resolving power
Which method is the only way to compensate for lens distortion?
Increase the camera’s distance from the subject.
The inability of a lens to bring wavelengths of white light into focus at the same plane is called:
astigmatism
Identify the cause of optical flare.
Internal reflections from glass-to-air surfaces of the lens.
Which problem has been practically eliminated by the practice of coating lenses?
optical flare
Which characteristic is an added benefit derived form lens coating?
Increased lens transmission of light.
Lens coverage of a normal lens is very near the angle covered by the human eye or about:
45 degrees
Which lens is the best choice for most investigative assignments?
Normal
Which factor is one disadvantage of using a wide-angle lens?
Converges parallel lines from the edges towards the center of the lens.
The basic design of a telephoto lens includes:
A positive element in front of and separated from a negative rear element.
Which feature is an advantage of a zoom lens?
You can vary focal length much faster than you can change lenses.
Macro photography ends and photomicrography (with microscope lens) begins at enlargements of about:
10x
Which of the following characteristics is a disadvantage of a macro lens?
Extremely short depth of field.
As a minimum, how often should you clean your lenses?
After every photographic mission or at the end of each day of shooting.
If you rub your lens shade too hard while cleaning it what could happen to the lens?
The protective black paint might come off and cause reflections.
