If you don't think mylar reflects heat you are ignoring fact.

Lumens is not how plants see light, you would need a PAR meter to get a reading of what your plant sees as photosynthetic energy. That's plainly spelled out in the link Weez provided, did you by chance read it?

Weezard shut me up already. I can't argue that "light burn" or "bleaching" happens when he posted a picture for proof. Nor am I trying to. I'm saying that if people are having an issue with their plants processing artificial light, that it probably is a combination of things rather than just too much light.

Notice how Weez thought it peculiar right away when he read the symptoms of this guys problem? Likely not from too much light, at least not on it's own. From everything I have seen and read it turns leaves white in spots. It doesn't fry them off like nute or heat burn.

Let me say again, I'm not arguing with the principle of a saturation point for light in plants. I just don't feel it's should be an accepted diagnosis until everything else is ruled out. I have seen quite a few people talking about this, but the only really good example of it I have come across on here is the one Weez just put up. Most of the others don't look like that. Hell I've even seen someone recently post they overlit their plant with CFL. I didn't post there because it seemed ludicrous to me. You all seemed a much better bunch to hash it over with.