What to do if your DSLR adjusts focus and it's still blurry

There are two reasons.

1, the focus distance is too close, has exceeded the nearest focus distance, so always unable to focus and blurred. The solution, widen the photo distance or horizontal direction to follow the focus, most of the SLR camera autofocus system, basically equipped with a word type of autofocus sensor, and on the basis of which developed into a cross or double-cross type of autofocus sensor. If the subject is moving horizontally, the success rate of focus tracking is higher.

2, the body of the refractor is not adjusted, even if the focus on the eyepiece to see the subject is still blurred. The solution, focus in the lens within the closest focus distance, focus distance is not close to the closest focus distance; adjust the diopter, until you see in the eyepiece is a clear subject.

Extended information

DSLR camera adjustments focus blur is not clear will also run out of focus, DSLR cameras shoot through the autofocus system, resulting in the focus of the photo and we need to shoot the focal point of the phenomenon of offset. Imagine a dartboard, when we need to choose the focus point is the center of the bullseye, half-press the shutter to focus without recomposing, and then press the shutter to shoot, the photo result is very fuzzy, while the center of the bullseye near the top or bottom but appear clear, this is running out of focus.

Large aperture lens out of focus, the larger the aperture, the farther the distance, the higher the probability of out of focus. You can get paper-thin depth of field and psychedelic out-of-focus when shooting at full aperture, but focusing requires full conditioning and skill.

Due to light, distance, and the subject (the contrast between dark and light where the subject is in focus), the machine can't accurately place this paper-thin bit of depth of field just right for our human visual perception, which results in out-of-focus. It is recommended that you try to shrink one stop of aperture to use it, and also to avoid purple edges.