for k in `ls |head` do echo $k exif -t FocalLength IMG_0016.JPG |grep Value done
IMG_0016.JPG Value: 200.0 mm IMG_0017.JPG Value: 200.0 mm IMG_0018.JPG Value: 200.0 mm IMG_0019.JPG Value: 200.0 mm IMG_0020.JPG Value: 200.0 mm IMG_0021.JPG Value: 200.0 mm IMG_0022.JPG Value: 200.0 mm IMG_0023.JPG Value: 200.0 mm IMG_0024.JPG Value: 200.0 mm IMG_0025.JPG Value: 200.0 mm