ADavidhazy <andpph@xxxxxxxxxxxxxxxxxx> writes: > Recognizing that although I work at a school where art reign supreme here are > some question related to DOF for you amusement. I forgot the answers! :) andy > > Quiz 4 - Depth of Field > This is a quiz related to Depth of Field and Depth of Focus. > > Question 2: > > Camera lenses can be focused on many object distances at one time. False > Question 3: > > Increasing the viewing distance to a print increases the perceived > depth of field. True > Question 4: > > Prints are normally viewed from a distance about equal to their > diagonals. True As a statement about reality, I haven't done the research to justify an opinion. It's not obviously crazy. I do believe it's part of the assumption underlying convention DOF calculations, anyway. > Question 5: > > The appropriate viewing distance for a 6x8 inch print made from a > 35mm negative is 10 inches True In line with #4, yes. Note that the "35mm negative" is irrelevant. > Question 6: > > Enlarging a negative increases the size of the circle of confusion > proportionally. > > True > False > > Question 7: > > Depth of field decreases rapidly as the distance between the > camera and the subject increases. False > Question 8: > > Hyperfocal distance is the nearest distance that appears sharp when the camera > is focused on infinity. False > Question 9: > > Unlike pinhole cameras lenses can only focus on one suject plane > with other planes recorded progresively unsharply True > > Question 10: > > Depth of field is the range of distances within which objects are > imaged with acceptable sharpness. True > > Question 11: > > Depth of field is directly proportional to the Circle of > confusion. True > Question 12: > > Depth of focus is associated with placement of the film with > respect to the image formed by the lens. > False > > Question 13: > > To maximize depth of field one should focus on 1.2 the hyperfocal > distance. False > MULTIPLE CHOICE QUESTIONS FOLLOW BELOW: > > Question 14: > > Which of the following is not a tool that a photographer can use > to change depth of in field in > photographs? > > a: f-number > b: object distance > c: focal length > d: lighting d. Except that changing d will often lead to a change in a. But d does not *directly* change DOF, and the others do. > Question 15: > > In the workshop the hyperfocal distance for the Tele-Optar at an > aperture of f/32 was? (in inches) > > a: 156 > b: 342 > c: 780 > d: 1528 Sorry, wasn't in the workshop that day :-) > Question 16: > > According to the textbook the permissible circle of confusion on a > print viewed at a distance of 10 inches is? > > a: 1/10 mm > b: 1/100 inch > c: 1/170 inch > d: 1/200 inch Sorry, don't have the textbook here. Skipped a couple others here for the same reason. > Question 19: > > In order to make a 6x8 inch print from a 35 mm negative it should > be enlarged: > > a: 2x > b: 3x > c: 4x > d: 6x d, About 6x. Was this a DOF question? > Question 20: > > Given any format camera extreme depth of field is associated with: > > a: short focal length lenses > b: normal focal length lenses > c: long focal length lenses > d: retrofocus angle lenses a Well, greatest; extreme can mean two different things. > Question 21: > > To obtain the greatest depth of field at a given f# the lens > should be focused on: > > a: infinity > b: the subject > c: the hyperfocal distance > d: 1/2 the hyperfocal distance c > Question 22: > > When a lens is focused at the hyperfocal distance depth of field > extends from: > > a: the subject to infinity > b: the camera lens to infinity > c: from lens 1/2 way to infinity > d: 1/2 the hyperfocal distance to infinity d I could easily have been fooled on this one. I know a, b, and c are wrong, so I picked d. But if d had said 1/3 say rather than 1/2, I wouldn't have known off the top of my head it was wrong. > Question 23: > > Viewed from a 10 inch distance Depth of Field in a contact print > of a 35mm negative always appears: > > a: larger than in an enlargement > b: the same as in an enlargement > c: smaller than in an enlargement b. > Question 24: > > Hyperfocal distance is a function that depends on: > > a: Lens focal length, lens aperture and size of Circle of > confusion > b: Object distance, Lens aperture and viewing distance > c: Lens type, lens aperture and lens focal length > d: Film format, Circle of Confusion and Lens Focal length a > Question 125: > > As the specified Circle of Confusion gets smaller the Hyperfocal > distance for a given lens and aperture: > > a: decreases > b: remains constant > c: increases > d: varies with the film format c > Question 26: > > Depth of Focus is particulary applicable to photography of: > > a: 2-dimensional subjects > b: 3-dimensional subjects > c: inanimate subjects > d: very deep subjects d, I suppose. That's just a special case of b, but it's a case where DOF matters even more than in the general b. > Question 27: > > The object distance at which one should focus to obtain the largest depth of > field given a specific lens and f-number is....? > > a: infinity > b: 1/2 the hyperfocal distance > c: the hyperfocal distance > d: 2 times the hyperfocal distance c -- David Dyer-Bennet, <mailto:dd-b@xxxxxxxx>, <http://www.dd-b.net/dd-b/> RKBA: <http://noguns-nomoney.com/> <http://www.dd-b.net/carry/> Pics: <http://dd-b.lighthunters.net/> <http://www.dd-b.net/dd-b/SnapshotAlbum/> Dragaera/Steven Brust: <http://dragaera.info/>
