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0 pointsxd13y ago0 comments

Are you aware of how little light you need to see? Just because you assume the light in the video is similar to a 40w bulb is short sighted (no pun intended). A 2W "pretty dim" incandescent bulb will illuminate a room no problem.

Human eyes can adjust very well to low light levels.

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pdonis13y ago· 2 in thread

It depends on what you're trying to do. For just minimal seeing, yes. For reading, or many kinds of tasks, not so much. There's not enough in the article to know for sure how they're pitching it to the people that might actually use it.

xdOP13y ago

I once done a stint in the military, and during training we had to use red light at very low levels to read and write at night time .. it is possible, just a world away from what the average human with access to electricity on tap is used to, I guess.

pdonis13y ago

Yes, you're right, I remember similar things from my time in the Navy. This kind of lighting regime is normal in the combat spaces of a ship, even in the daytime.

The GravityLight article does say that it's meant to replace kerosene lamps, which according to Wikipedia range from 20 to 100 lumens:

http://en.wikipedia.org/wiki/Kerosene_lamp

This is about the equivalent of a 1.6 W to 8 W incandescent bulb, so you're right, I was too quick to dismiss the numbers as being too low. They're certainly low compared to what first world citizens are used to, but they are roughly equivalent to what the target users are used to.

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