[effisfor]

Depth of field, quite literally here! Here are some rules of thumb: If you increase depth of scene, you can use depth of field in two ways. In portraits, you can create greater subject separation because the closer focal point of chicken will be in focus, but the horizon line will be very blurred. Taken at human eye-level, most of the background of a chicken will be grass that's close-by, and therefore a similar blurriness (or 'bokeh'). That makes it harder to discern subject.

Secondly, if you open up the depth of field with a very deep scene, you create more possibilities for composition, framing or storytelling. Again, all you have at human eye level is chicken/grass. At chicken eye level, with a very deep focal range, you might also be able to tell the story of the chicken in 'the great outdoors', you may see mountains and forests on the horizon etc.

Hope that helps.