Large Prime
Member
That shift is REAL minor.Do you know if there is a spectrum shift from vertical to horizontal with the 4200k as the elite agro bulb does?
http://www.lighting.philips.com/pwc_li/ca_en/connect/tools_literature/downloads/elite_design_guidev7.pdf
Cut And Paste
"
4.3 18BBurning positions of the lamp
The MasterColorCDM Elite MW lamps are “universal burning”, which means that they can be operated
in any orientation. Most common applications will be horizontal and vertical operation. Light-technical
properties are slightly different in horizontal burning position compared to the vertical position. When
rotating the lamp from the vertical towards the horizontal position, the color temperature may increase
by about 100K and the light output may decrease by up to 2%.
In horizontal burning position, it is recommended to mount the lamp such that the long frame wire is on
top. The reason for this is that in horizontal position, convection processes inside the arc tube make the
middle of the arc bend slightly upwards which changes the temperature profile in the arc tube.
Magnetic fields caused by electric currents through the frame wires inside the lamp can either enhance
or decrease this arc bending effect. The arc bending effect is minimized when the long frame wire is on
top.
"
So maybe a 2% change. If you run horizontal and don't pay attention to the long frame wire. Are you worried about this? Honestly for how hard it is to find a decent vertical reflector, i would not worry. Do you? Or do you run old school vertical "Cones"
But to answer your question, all the elite bulbs will do this. Not sure about the mogul, or any of the all starts.