Reading that thread the picture was linked from:
The MH used to compare was a Hamilton 20K DE using a Current USA fixture and ballast.
I dont know how long they've been out on the market or if Sanjay Joshi or anyone else has tested the Hamilton 20K's (DE or SE) for PAR numbers...
But the Hamilton 14K (which should have better PAR than the 20K) had moderate PAR readings compared to other bulbs in the class (Phoenix 14K for example).
That picture and those numbers are misleading now that we know what is being compared IMO.
Dont get me wrong, I'm still very happy with my Radion's, but that picture and those numbers imply more than is really happening.
Now, if it were being compared against a 250 Watt Iwasaki 6500K bulb on an HQI ballast and got those numbers, that's a whole different matter all together.
Mojo,
Since we know that PAR meters register LED lights lower than they really are due to the blue skew....is it possible that 20K bulbs get lower PAR readings due to the blue skew as well? I know that there is alot of red & green in MH bulbs that may not be visible to the human eye which what will boost the PAR numbers somewhat...
But just trying to get a feel for it here....
Hope that makes sense.
Nick