10 most difficult optics riddles A list of ten (out of 16) optics related questions that are the most often answered incorrectly Optics quiz What term would photographers use to describe the quality of blurred part of the photo? Bokeh has been defined as "the way the lens renders out-of-focus points of light". It can be good or unpleasant, depending on the lens aberrations and aperture shape. The term comes from Japanese for "blur".very hard 33% diffractiondiffraction33%bokehbokeh33%outfieldoutfield19%overexposureoverexposure13%Created by: globalquiz.org. Statistics based on 6102 answers in 2 languages »photography riddles » In what process sky colors (including blue sky and red sun) are created?Rayleigh scattering, named after the British physicist Lord Rayleigh (John William Strutt), is an elastic scattering of light or other electromagnetic radiation by particles much smaller than the wavelength of the radiation. very hard 33% iridescenceiridescence11%Rayleigh scatteringRayleigh scattering33%miragemirage12%atmospheric refractionatmospheric refraction42%Created by: Ninjai. Statistics based on 5316 answers in 3 languages »optical illusions riddles » The bright circle around the Sun seen in the picture is known as a halo. What causes it?Refraction of light in ice crystals. Halo is the name for a family of optical phenomena produced by light interacting with ice crystals suspended in the atmosphere. Halos can have many forms, ranging from colored or white rings to arcs and spots in the sky. Among the best known halo types are the circular halo (properly called the 22° halo), Other common optical phenomena involving water droplets rather than ice crystals include the glory and the rainbow. very hard 36% refraction of light in ice crystalsrefraction of light in ice crystals36%refraction in the lens of the eye or lensrefraction in the lens of the eye or lens31%refraction of light in water dropsrefraction of light in water drops25%reflections from the water surfacereflections from the water surface6%Created by: Tschuka. Statistics based on 9750 answers in 3 languages »atmosphere riddles » A person who has 4 types of color receptors is called ...Tetrachromat. Man is usually sensitive to about 500,000 colors. Tetrachromacy is the condition of possessing four independent channels for conveying color information, or possessing four types of cone cells in the eye. Organisms with tetrachromacy are called tetrachromats which can see up to 99 million shades. very hard 37% Such people do not existSuch people do not exist20%QuatroculusQuatroculus32%ChromosomChromosom9%TetrachromatTetrachromat37%Created by: Tschuka. Statistics based on 1997 answers in 2 languages »eyes riddles » This optical phenomenon, appearing on misty mountainsides, is called...Brocken spectre. A Brocken spectre or mountain spectre, is the apparently enormous and magnified shadow of an observer, cast upon the surfaces of clouds opposite the sun. The head of the figure is often surrounded by the glowing halo-like rings of a glory—rings of coloured light that appear directly opposite the sun when sunlight meets a cloud of uniformly-sized water droplets. The phenomenon can appear on any misty mountainside or cloud bank.very hard 39% Side rainbowSide rainbow12%HaloHalo40%Brocken spectreBrocken spectre39%Sun DogsSun Dogs7%Created by: Tschuka. Statistics based on 375 answers in 3 languages »mountains riddles » Which of the following is the worst for eyesight during a sunny day?Wearing sunglasses without UV filter. Wearing sunglasses witout UV filter causes the pupils to dilate and eyes to absorb more UV rays than they normally would without the sunglasses. Hence, it's much better not to wear sunglasses at all, than to wear ones without UV filter.hard 47% wearing sunglasses with UV filterwearing sunglasses with UV filter3%wearing sunglasses without UV filterwearing sunglasses without UV filter47%not wearing sunglasses at allnot wearing sunglasses at all35%wearing sunglasses inside buildingswearing sunglasses inside buildings12%Created by: Ninjai. Statistics based on 10964 answers in 2 languages »light riddles » Which organisms in nature can emit light?Firefly and honey fungus. Bioluminescence occurs widely in marine vertebrates and invertebrates, as well as in some fungi, microorganisms including some bioluminescent bacteria and terrestrial invertebrates such as fireflies. In some animals, the light is bacteriogenic, produced by symbiotic organisms such as Vibrio bacteria; in others, it is autogenic, produced by the animals themselves.hard 47% firefly (insect)firefly (insect)46%honey fungus (mushroom)honey fungus (mushroom)2%none of thesenone of these2%firefly and honey fungusfirefly and honey fungus47%Created by: Tschuka. Statistics based on 4743 answers in 2 languages »insects riddles » What kind of lens was most likely used for this photo?Fixed focal length. Such shallow depth-of-field is possible with lens of large aperture size (small f-number). The large aperture is a typical feature (and advantage) of a fixed focal length lens. The photo was taken with a 50mm f/1.4 lens. hard 51% fixed focal lengthfixed focal length51%zoomzoom15%telephototelephoto10%macromacro21%Created by: Debbie Fox. Statistics based on 14917 answers in 2 languages »lens riddles » Which of the following camera lenses are typically more expensive?F/1.8. The smaller the f-number, the larger relative aperture there is, and that means more light for the exposure. Each aperture has half the light gathering area of the previous one.hard 53% f/1.8f/1.853%f/2.4f/2.48%f/2.8f/2.813%f/3.5f/3.525%Created by: karate kid. Statistics based on 9963 answers in 2 languages »technology riddles » The rainbow is violet on the inside of its arc. What color is it on the outside?Red. Visible light spans from red to violet. It is easy to remember, since wavelengths just outside the visible range are called infrared and ultraviolet.hard 55% blueblue15%greengreen9%yellowyellow19%redred55%Created by: Hà Linh Chi. Statistics based on 20918 answers in 2 languages »colors riddles » Play optics quiz and see all the questions.