I am curious though. You say the mr16 is not compact enough for your extremely limited space. Is this for a headlight? It would be very very difficult to conceive of a more compactly engineered form, that alteady provides the beaming (spot) reflector ins so small a package as the, once again, already engineered mr16. All that it lacks, and its a serious lack, is the oblonged beam of a true road use headlamp. The newest automobile headlights are amazingly well engineered for this. You can stand in front of a well designed headlight today on a new model car and hardly notice the brightness. Bend your knees slowly lowering your gaze and at a very distinct point the beam is blinding. Theres a sharp horizontal demarcation that you dont get with a non street-designed bulb.
The off the shelf "landscape" mr16s that im using from home depot for moped headlights put out 1240 lumens straight from the lighting coil of my e50. Thats considerable. I worry that its enough to bother oncoming traffic, but not once in the past three years have i been flashed in irritation.
The 35 degree cone of my mr16 limits the amount of lumens i can pour down the roadway since the upper edge of the round beam can blind oncoming traffic, but its not that bad a limitation. Its easy to pull up to a big bright wall somewhere and adjust the beams optimally by hand.
Drinking too much beer tonight. Probably a bit overzealous on all this. Apologies all around.
Good night. (edited)