Re: beamshape&hotspot:vertical vs. horizontal fila
Bill,
I know of no accounts of anyone ordering replacement bulbs from the Vector website. They are about $5 a piece and $5 a piece for shipping. $10 is a lot of money to find out if they are the A bulbs or if they are the same H Vector-branded bulbs found retail. I am not willing to drop money to find out.
Phy,
I agree with your observations regarding H versus V spots. I don't understand what you're saying about square filaments though. I'm looking at one of my 64625HLX and filament looks like a pack of chewing gum. A flattened shoe-box shape that is rectangular in all dimensions.
I think another way to think about the spot shape is to think of it not as a result of the filament orientation, per se, but rather a function of the deviation of the filament geometry from the one-dimensional focal point and the resulting defocus. In other words, sufficiently large H filaments create the bilobe because the ends of the filament drift off the focal point laterally extending the hotspot in that plane. Large A filaments create a fuzzier but rounded hotspot. This is borne out by careful measurement of the hotspots for both bulbs above. The diameter of the A hotspot is greater than the narrow diameter of the H bulb's spot. To me, this implies that the smearing occurs in coaxial cylinders around the axis of the filament.
Wilkey
Wilkey