I've been trying to change the depth of field on a Nikon D5200 for 2 hours and I can't seem to get it to work. I have to take photos and videos of people tomorrow (this is not my camera). The depth of field is currently too low to take photos in focus. I try to change the aperture size on the camera and there is no noticeable change even if I go from f/5.6 to f/32. Any ideas?
EDIT: After thinking about it for a little bit, is it possible that with the lens I am using, it is not possible to have the bokeh effect that I'm looking for (filming an interview)? I am using this lens: https://www.nikonusa.com/en/nikon-products/product/camera-lenses/af-s-dx-zoom-nikkor-18-55mm-f%252f3.5-5.6g-ed-ii.html
I think it may work for things with very low depth (a white board), but it's not possible to achieve a good depth of field for a person sitting in a chair or a group of people.