Selective focus is a technique used to create a shallow depth of field, where the subject is in sharp focus while the background is blurred. This helps to isolate the subject and draw attention to it.

Aperture is the primary factor that affects the depth of field. A wider aperture (lower f-number) results in a shallower depth of field, while a narrower aperture (higher f-number) results in a greater depth of field.

Bokeh is the term used to describe the aesthetic quality of the out-of-focus areas in an image. It refers to the way the out-of-focus highlights and shapes appear, and can contribute to the overall mood and atmosphere of the image.

Prime lenses, especially those with wider apertures (lower f-numbers), are generally preferred for achieving a shallow depth of field and pronounced bokeh effect. They offer a fixed focal length, allowing for more precise control over the depth of field.

Increasing the distance between the subject and the background increases the depth of field, making both the subject and the background appear sharper. This is because the light rays from the subject and the background are more parallel when they reach the lens, resulting in a greater depth of field.

Shutter speed does not directly contribute to the creation of bokeh in an image. Aperture, focal length, and lens quality are the primary factors that influence the bokeh effect.

A wider aperture (lower f-number) results in a shallower depth of field, while a narrower aperture (higher f-number) results in a greater depth of field. This is because a wider aperture allows more light to enter the lens, causing the light rays to diverge more and resulting in a shallower depth of field.

Using a prime lens with a wide aperture (lower f-number) is an effective technique to achieve a shallow depth of field and isolate the subject from the background. Prime lenses generally offer wider apertures compared to zoom lenses, allowing for more precise control over the depth of field.

Focal point is the term used to describe the point at which the lens focuses the light rays. It is the point where the light rays converge after passing through the lens, and it determines the sharpness of the image.

Shutter speed does not affect the size and shape of the bokeh in an image. Aperture, focal length, and lens design are the primary factors that influence the appearance of the bokeh.

Using a narrow aperture (high f-number) increases the depth of field, resulting in a greater portion of the image being in focus. This is useful for landscape photography, where you want both the foreground and background to be sharp.

A well-executed bokeh effect should have smooth and creamy out-of-focus areas, sharp and defined edges of the subject, and a natural and pleasing transition between the subject and the background. Distracting and busy background elements can detract from the overall impact of the bokeh effect.

Depth of field is the term used to describe the range of distances that appear sharp in an image. It is affected by factors such as aperture, focal length, and the distance between the subject and the camera.

Using a narrow aperture (high f-number) increases the depth of field, resulting in a greater portion of the image being in focus. This is the opposite of what is desired for a shallow depth of field.

A longer focal length lens compresses the perspective, making the background appear closer to the subject. This results in a shallower depth of field, where the background is more blurred compared to a shorter focal length lens.