Photography - Sharpness, Macro, Lighting, DoF

Question 1

Describe a macro lens.

Answer 1

Lens specifically designed for close-up work, with long barrel for close focusing anf optimized for high reproduction ratios.

Question 2

What is the use for continuously-variable focal length macro lenses?

Answer 2

Suitable for virtually all macro subjects.

Question 3

For what purposes can macro lenses with a focal length of 45-65 mm be used for?

3

Answer 3

• Product photography
• Small objects that can be approached closely without causing undesirable influence
• Scenes requiring natural background perspective

Question 4

For what purposes can macro lenses with a focal length of 90-105 mm be used for?

3

Answer 4

• Insects
• Flowers
• Small objects from a comfortable distance

Question 5

For what purposes can macro lenses with a focal length of 150-200 mm be used for?

2

Answer 5

Insects and other small animals where additional working distance is required.

Question 6

Describe flood lights.

Answer 6

Provide a directional source of light.

Question 7

What is the purpose of the barn doors on flood lights?

Answer 7

Help control light flow

Question 8

What is the purpose of reflectors on flood lights?

Answer 8

Lighten the shadows created.

Question 9

Compare spotlights to floodlights.

Answer 9

Spotlights provide a more directioonal light source.

Question 10

What is the purpose of the rear control knob on spotlights?

Answer 10

Helps focus light beam

Question 11

What can be done to a spotlight if further directional light is required?

Answer 11

Can be outfitted with a snoot

Question 12

What is tenting in photography?

Answer 12

Lighting through a translucent medium to produce an even, diffused field of light devoid of reflected details (for shiny objects).

Question 13

What can be done to eliminate the rainbow effect created when photographing reflective surfaces like CDs and DVDs?

Answer 13

Tented lighting in combination with a large aperture and limited depth of field.

Question 14

What is transillumination?

Answer 14

Illumination produced by lighting through a translucent medium.

Question 15

What is oblique lighting useful for?

2

Answer 15

• Accentuating surface detail
• Photographing cylindrical objects

Question 16

What is the standard resolution of an AFIS print?

Answer 16

1000 ppi

Question 17

What is dark field illumination?

Answer 17

Transmission of light below the object to be photographed.

Question 18

In what instances is dark field illumination beneficial?

Answer 18

Powderedd finger/footwear impression on transparent materials.

Question 19

How can lens flare be avoided during dark field illumination?

Answer 19

Never direct light at camera lens

Question 20

Describe background separation lighting.

Answer 20

Subject separated from background on clear glass.
Separate lighting used for background and subject.

Question 21

In what instances is background separation lighting useful?

Answer 21

Photographing small objects and physical matches involving textured materials.

Question 22

Define depth of field.

Answer 22

Distance between nearest and farthest objectd which can be brought into acceptable focus.

Question 23

What is the relationship between f-number and DoF?

Answer 23

Greater the f-number, greater the depth of field.

Question 24

Describe the conditions under which greatest DoF is acheived.

3

Answer 24

• High f-number
• Short focal length
• Distant subject

Question 25

True or false: There is only one plane of actual focus.

Answer 25

True

Question 26

Describe the typical extension of the DoF behind and in front of the plane of focus.

Answer 26

1/3 in front
2/3 behind

Question 27

Describe the extension of the DoF behind and in front of the plane of focus in close-up photography.

Answer 27

1/2 infront
1/2 behind

Question 28

List the three factors that affect depth of field.

Answer 28

1. Camera to subject distance
2. Lens opening or aperture
3. Physucal size of digital sensor or film

Question 29

How does camera to subject distance influence DoF?

Answer 29

Closer you are to the subject, less depth of field.

Question 30

How does lens openining or aperture affect DoF?

Answer 30

Smaller the aperture, greater the depth of field.

Question 31

How does the size of the sensor or film affect DoF?

Answer 31

Smaller sensor or film = larger DoF

Question 32

What is the most practical method to increase DoF, and what does this usually necessitate?

Answer 32

Smaller aperture
Slow shutter speed and/or tripod

Question 33

Define the inverse square law.

Answer 33

Light falls off in such a way that as the light source to subject distance doubles, the light falls off by a factor of 4.