We have already seen, under the EN 379 standard, the visibility factor of an ADF helmet is rated from 1 to 3, with 1 being the best, whereas, for passive welding hoods, there is just a single optical class. Apart from this specification-wise difference, I have experienced superior optics using modern ADFs, which is especially advantageous for precise welding operations. With passive ones, I have mostly experienced poorer lens clarity.