Got a new POB H.I.D. - Not as bright as existing one??

OK, I have had my first POB for about 2-3 months. I don't use it daily, but I make sure to use it at least once a week and then keep it charged full. I got a new one in today. I took it out of the box and charged it full. I turned them both on and pointed them at the ceiling. The new one is definately bright, but not as birght as the old one. The old one has a complete white hotspot while the new one has a bright white center, but the edge of the hotspot is more of an off white. Does the new bulb have to "break - in"? Is there something I am missing?

Any help would be appreciated!

BIG_PAPA said:

OK, I have had my first POB for about 2-3 months. I don't use it daily, but I make sure to use it at least once a week and then keep it charged full. I got a new one in today. I took it out of the box and charged it full. I turned them both on and pointed them at the ceiling. The new one is definately bright, but not as birght as the old one. The old one has a complete white hotspot while the new one has a bright white center, but the edge of the hotspot is more of an off white. Does the new bulb have to "break - in"? Is there something I am missing?

Any help would be appreciated!

Click to expand...

It's really not uncommon for two lights of the same model to have variations in output.

There are probably many factors that could be contributing to what you're seeing. Firstly, if the bulb isn't in the exact same focal point in relation to the reflector that can cause perceived differences in the overall amount of light being produced. This might account to your statements in regards to the hot spot and the colors near the edge. Simple shims and "X" or "Y" adjustments can help to make the beam the best is can be.

There is also the issue that deals with the number of assembled components involved which make up the light. No two parts are exactly alike and when the effects are multiplied they combine to cause one beam to look different than another. These differences could be in actual lumen output, color or shape of beam. The ballast itself may be slightly less efficient in one example and slightly more efficient in another example. If you get the best in one case and the worst in another case that could be enough to allow a discernible difference to be recognized. The ballasts themselves might not be delivering the exact same wattage to the bulb but only be within the manufacturers acceptable range. If that range is plus or minus 3W then they could have a sample variation of up to 6W which could be easy to see.

Finally, no two bulbs are the same and there is indeed a break in period, most of which occurs within the first ten hours or so. The bulb is continuously changing color and efficiency throughout it's life span the changes after the first several hours happen much slower.

Even expensive HIDs are subject to most of the same general inherencies but are probably not as dramatic due to tighter quality control.

Patriot,

Thanks for your response, your explanation seems spot-on. I took the lights to a hallway and shined them down it. I think some of what I percieved as "not - as - bright" may have been more of a focus difference. Two different shape hot spots. Also, as it burned though it's first cycle, the new bulb did seem to get a little brighter and closer in color to the first one. I may just let it break in for a couple of cycles and then mess with the focus. How hard is it to shim and / or focus these bulbs?

Thanks again for your help!

BIG_PAPA said:

Patriot,

Thanks for your response, your explanation seems spot-on. I took the lights to a hallway and shined them down it. I think some of what I percieved as "not - as - bright" may have been more of a focus difference. Two different shape hot spots. Also, as it burned though it's first cycle, the new bulb did seem to get a little brighter and closer in color to the first one. I may just let it break in for a couple of cycles and then mess with the focus. How hard is it to shim and / or focus these bulbs?

Thanks again for your help!

Click to expand...

You're welcome. It's not difficult to shim at all. Usually, the bulb sits slightly too far into the reflector and by adding thin metal washers one at a time between the bulb base and reflector you can fine tune the hot spot. Sometimes the bulb is very slightly canted, crooked or off axis from this base causing the plasma globe to be slightly closer to on point on the reflector. This can also be slightly compensated for but mess around with the depth adjustments before you get into that since it's harder to explain and it's probably not necessary. If you inevitably touch the bulb with your bare fingers just be sure to wipe it down with an lint free alcohol swab before you turn the light back on. Finger oils aren't good for the glass.