根据雅科夫列夫的做法,我会仿製一張和他完全相同的图。第一次是在室內拍照,用的是一般大型照相机。由於室內光線不够强,距离不够大,因之只得到每厘米60條的光柵。雖可看到衍射现象但由於線條太少,結果不够好。第二次和第三次我改用“Rolleiflex”小型照相机。都是在室外强陽光下進行拍照的。用的光圈是22,曝光時間是1/2—1/5秒。由物鏡到圖的距离分别為30、35或40呎。用的膠片是“來卡”(俗稱黑白片)。所製成的是每厘米150、200和300条线的光柵。如果通過這種光栅看普通室內電燈,則可見到零級、一级和二 According to Yakovlev’s approach, I will copy a picture exactly like him. The first time in the indoor photo, using a general large camera. As the indoor light is not strong enough, the distance is not big enough, so get only 60 per centimeter grating. Although you can see the diffraction phenomenon but too few lines, the result is not good enough. The second and third time I switched to a “Rolleiflex” compact camera. Are taking pictures outdoors in the strong sunlight. The aperture is 22, exposure time is 1 / 2-1 / 5 seconds. The distance from the objective to the figure is 30, 35 or 40 feet respectively. Film used is “to card” (commonly known as black and white film). The result is a grating of 150, 200 and 300 lines per centimeter. If you look through this grating ordinary indoor electric light, you can see the zero level, level and two