میشه جواب این سوال فنی در باره ی عکاسی رو به انگلیسی بدید . در حد چند خط.

A wide aperture gives you a shallow depth of field (only the foreground is sharp) A narrow aperture gives you a deep depth of field (everything is sharp

دیافراگم باز به شما عمق میدان کم می دهد (فقط پیش زمینه واضح است) یک دیافراگم باریک به شما عمق میدان عمیق می دهد (همه چیز واضح است

Aperture refers to the opening in a camera lens through which light passes to enter the camera. It’s one of the three pillars of photography, alongside shutter speed and ISO. The size of the aperture is measured in f-stops (e.g., f/1.8, f/4, f/16), with lower numbers indicating a larger opening and higher numbers indicating a smaller opening.

Depth of field (DoF) is the range of distance within a photo that appears acceptably sharp. Aperture plays a crucial role in controlling depth of field:

در نورشناسی، اَپِرچِر (به انگلیسی: aperture) یا دریچه یک حفره یا روزنه است که نور از آن عبور می‌کند.[۱] به‌طور خاص در عکاسی، اپرچر و فاصله کانونی، زاویهٔ پرتوها را تعیین می‌کنند که به کانون عدسی می‌رسند و سپس روی حسگر تصویر تابیده می‌شوند.

a space through which light passes in an optical or photographic instrument, especially the variable opening by which light enters a camera.

One of the three parameters is exposure, and by increasing and decreasing the aperture of the lens, it affects the amount of light entering a photo.  The larger the aperture, the brighter the image and vice versa.  But the larger the aperture, the smaller the distance that produces sharp images.

Aperture is the lens opening in photography, controlling light and depth of field. A wide aperture  creates a shallow depth of field, blurring the background. A narrow aperture  results in a greater depth of field, keeping more of the image in focus.

Aperture is one of the three exposure parameters and affects the amount of light that enters a photo by enlarging and reducing the aperture of the lens. The larger the aperture, the brighter the image and vice versa. But the larger the aperture, the smaller the distance that produces sharp images.

the opening in the lens that allows light to enter the camera and onto the sensor or film. The size of this opening can be adjusted by changing the aperture settings.Aperture and focal length each contribute to composition in their own unique way. When you learn how to pair different aperture and focal length measurements together, you can take gorgeous, jaw-dropping photographs.