Ask the photographer for help. How does a SLR camera focus on the distance with a medium telephoto lens to obtain a shallow depth of field effect? For example, shooting birds, the focal length is far

Ask the photographer for help. How does a SLR camera focus on the distance with a medium telephoto lens to obtain a shallow depth of field effect? For example, shooting birds, the focal length is far away, how about it? The effect of shallow depth of field is generally related to two factors, one is the aperture size and the other is the magnification.

The larger the aperture, the greater the magnification and the shallower the depth of field.

The magnification is related to focusing, and the closer the alignment is, the greater the magnification is. For example, when you focus on the nearest point, your lens magnification reaches the maximum. At this time, the picture is all blurred, even if the aperture is small, it exceeds F 10.

In other words, under the same aperture, the closer you are to the bird, the greater the proportion of the bird in the photo and the shallower the depth of field.

In fact, the depth of field in the above picture is not particularly shallow. Just look at the branches where the birds stand, and only the distance is blurred.

Your 55-250 should also be able to shoot this effect. If the aperture is not fully open, get closer to the bird.