what do you mean bigger? they are 3mm X 3mm, smaller than lm561c (5.6mm x 3mm), and the high power diodes are 3.5mm x 3.5mm. i also don't really care about efficiency i just want most overall power. it's still more lumens total if a little less efficient. i want these lamps to last 2 years most because i'm sure i'll be upgrading after 2 years anyways with how fast LED tech is moving, then it'll become a veg light or something
@CobKits do you think a cheap lux meter, like the ones built in to samsung phones, is good enough to give an approximation when using white light LEDs? just until such time a PAR meter can be afforded...