L Gebhardt
Member
Lens selection, as covered above, is a huge difference. In addition to the focal length you should consider aperture and how it affects both depth of field and exposure.
Exposure is easy. At the same aperture and ISO the shutter speed will be the same.
Depth of field needs to consider display size. If we compare a print from each of these hypothetical cameras we might have a 24MP image with 6000x4000 pixels. At 300ppi that will print at 20x13.3 inches. If the print from the full frame camera was shot at 35mm 5.6 the APS-C camera would need to shoot at ~24mm f/4 to match the angle of view and depth of field in the print. It also gets you one extra stop of light so lower ISO or faster shutter speed. It also means you may not find APS-C lenses with as shallow of depth of field for the same angle of view.
Exposure is easy. At the same aperture and ISO the shutter speed will be the same.
Depth of field needs to consider display size. If we compare a print from each of these hypothetical cameras we might have a 24MP image with 6000x4000 pixels. At 300ppi that will print at 20x13.3 inches. If the print from the full frame camera was shot at 35mm 5.6 the APS-C camera would need to shoot at ~24mm f/4 to match the angle of view and depth of field in the print. It also gets you one extra stop of light so lower ISO or faster shutter speed. It also means you may not find APS-C lenses with as shallow of depth of field for the same angle of view.