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1.D F2 can also be written as 1: 2 A is macro, b is focal length, and c is manual focusing.

2.c junior high school physics, do not explain

3. robert capa

4.C F value = focal length/aperture, focal length remains unchanged, f value doubles and aperture doubles.

5.c exposure according to the background, the background is bright and sets off the black body.

6. The B aperture is too large and the sharpness is low, and the aperture is too small to be diffracted.

7. Of course, the exposure meter measures the exposure.

8. A selfie camera is abbreviated as B for axis shift, C for polarized light and D for neutral gray.

The abbreviation of 9.9. B time value a is Av C, and A-Dep D is not an exposure mode.

10.c The range of common portraits is 85- 135, which is too short for deformation and too long for stereoscopic effect. Only c is in this range.