The Beauty of National Geographic Photography

You said: "Contrast" is the reason. The premise is that the foreground and background contrast strongly.

Clear the dark background with telephoto, measure the frog's light, make the background itself too dark, and then darken the "black" in photoshop software (only for the area below the gray 128 area in the photo-this is the background-effective), and the background has almost no details.

Of course, the rogue's practice is to dig out the frog directly and stick it on a black background. Most of them have to superimpose the soft light of a frog to simulate the light of the frog and the surrounding space, but the effect is not so natural.