About 1290µmols/m^2/sec is what your canopy is experiencing. Before realworld taxes(walls, reflectors, lenses, zippers, seams, dust...you get it).
49wx4=196w
196 x 51%=99.96radiant watts
99.96radiant watts x 4.67µmols= 466.81
466.81÷.36m^2 =1296.7µmols/m^2/sec
Plenty of light. But not too much despite what you might hear. And will guarantee you max your space. Or have power to expand a little down the line. Plus you can always dim it.
What you will need to do to accommodate that much light is to adjust its relative intensity by adjusting the clearance/height. 40cm is too low for that much light. No matter how high you hang it in the tent with that much light, you should actually notice the best performance with the most clearance as opposed to very close or even at what is considered high normally.
http://biology.mcgill.ca/Phytotron/LightWkshp1994/1.5 Bugbee/Bugbee text.htm
CONCLUSIONS
Differences in radiation quality from the six most common electric lamps have little effect on photosynthetic rate. Radiation quality primarily alters growth because of changes in branching or internode elongation, which change radiation absorption. Growth and yield in wheat appear to be insensitive to radiation quality. Growth and yield in soybeans can be slightly increased under high pressure sodium lamps compared to metal halide lamps, in spite of greatly reduced chlorophyll concentrations under HPS lamps. Daily integrated photosynthetic photon flux (mol m-2 d-1) most directly determines leaf anatomy and growth. Photosynthetic photon flux levels of 800 μmol m-2 s-1 are adequate to simulate field daily-integrated PPF levels for both short and long day plants, but plant canopies can benefit from much higher PPF levels.
