Photography FREE Photography Lens Optics and Selection Questions and Answers 2

Question 1

What does the term 'chromatic aberration' refer to in lens optics?

Accepted Answer

Color fringing caused by a lens failing to focus all wavelengths to the same point

Answer

Barrel distortion at wide focal lengths

Answer

Loss of sharpness due to diffraction at small apertures

Answer

Vignetting in the corners of an image

Question 2

Which lens type is best suited for compressing the apparent distance between foreground and background elements?

Accepted Answer

Telephoto lens

Answer

Wide-angle lens

Answer

Fisheye lens

Answer

Macro lens

Question 3

What is the primary advantage of an aspherical lens element?

Accepted Answer

It corrects spherical aberration more effectively than a standard spherical element

Answer

It increases the maximum aperture of the lens

Answer

It eliminates the need for image stabilization

Answer

It reduces the weight of the lens by half

Question 4

A photographer needs a lens with a constant maximum aperture of f/2.8 across a zoom range of 70-200mm. What type of lens construction achieves this?

Accepted Answer

Internal zoom with a complex multi-group optical design

Answer

Variable aperture with a single moving element

Answer

Fixed-body prime lens construction

Answer

Retrofocus wide-angle design

Question 5

What effect does a lens with a large number of rounded aperture blades have on out-of-focus highlights?

Accepted Answer

It produces smoother, more circular bokeh

Answer

It creates harsh polygonal shapes in the bokeh

Answer

It eliminates bokeh entirely

Answer

It increases depth of field at all apertures

Question 6

What is 'focus breathing' in a lens, and when is it most problematic?

Accepted Answer

A shift in focal length when changing focus distance, most problematic in video work

Answer

A mechanical vibration in the autofocus motor during continuous shooting

Answer

Air movement inside the lens barrel in cold weather

Answer

The sound produced by ultrasonic focus motors