This shows the relative brightess levels of both the DEL250 and the S150 series illuminators. The 250 is bright even in well lite rooms while the 150 is washed out. However, to show that everything is relative, the last picture shows two S150 illuminators being tested with some looped cable. You’ll notice that the cable in this picture looks very bright while the same S150 illuminator/cable combination looks dull when compared to the 250w.