[duskwuff]

It's not so much about the magnification as it is about the light-gathering surface. The human eye has a relatively small aperture; a professional camera lens has a huge aperture, and it focuses all the light from there onto the camera sensor.

Higher magnification actually makes it slightly safer, because the image of the sun ends up magnified and spread out over a larger part of the sensor. Low magnification means it all goes to one point.