Are you shortsighted? If you are, then focusing the lens to infinity would have the same effect like you see things without your spectacles.dRebelXT said:My lens is 70-300mm IS USM, the nearest focusing distance is 1.5m for all focal ranges.
When I put a 250D close up filter in the front to shoot things within 1.5m, how does it
affect the quality of subjects beyond 1.5m?
Closeup lenses ("filters") work by shortening the focal length of the lens. In light of this, the depth of field of a lens + closeup "filter" should be larger than that of the bare lens when focused at the same distance.raptor84 said:Close up filters saacrifice min focus distance for DOF. So you can focus closer but your max DOF becomes very small, also there will be some pronounced barrel distortion near the edges.