If he "experiments" with his 3 stop ND filter and his 1.5 stop polarizer, his shutter and/or sensor will be damaged. If you are using only an 8 stop filter for your camera, you are at risk (Are you really sure that your filter is only 8 stops?). Check B&H Photo, Adorama, Thousand Oaks Optical, and the NASA website and see the minimum is 16.5 stops (in photographic ND terms, 100,000X). If you are using a DSLR, your eyes are at risk. With a mirrorless, at least only your camera will be at risk. When I was choosing what level light reduction using welders glass, I tried ND 16, ND 17, ND 18, and ND 19 darknesses (16 to 19 stops). Although 16 and 17 were too bright for my viewing taste, they were more than acceptable for a camera. The 19 was too dark for my taste. Based off my own experience, if you are only using an 8 stop filter, you are only taking an unnecessary risk of camera damage and/or permanent eye damage. And for the OP, at only 4.5 stops, it would be a very ignorant decision.