This image, made with Blender and GIMP, shows a comparison of three types of computed reflections: accurate with path tracing (left, should be same as with ray tracing etc.), approximate with environment mapping (middle, inaccuracies and lack of self reflections can be seen), approximate with screen-space reflections (right, missing parts due to lack of information can be seen). The models were made by me. The image was manually post-processed to correct colors between different renderers etc.
<a href="//commons.wikimedia.org/wiki/User:Drummyfish" title="User:Drummyfish">Drummyfish</a>
<span class="int-own-work" lang="en">Own work</span>