"The SCL-D can just be seen with the naked eye even in strong day light, however its the glasses (supplied) that make the difference. Really psychedelic on a sunny day!!! Come the evening light I was able to set the level of a large new pond to equal a new circular drive to the existing entrance of the house instantly!!! Then the next day internal floor levels for concreting instantly. Jobs that would normally be fiddly and take ages. Second concern was the set up, however the SCL-D can simply be sat anywhere and it stabilises instantly. Its range of beam choice is very good as is its accuracy. Only down side is it costs more than the others but then I'm NOT left wishing I'd bought a different set up."