S4 ellipsoidal with HPL 750 bulb smells like its burning

Do all 6 units have the exact same type of HPL 750W lamp?  There are extended-life HPLs that have slightly warmer color temperatures.  This could cause some bulbs to appear duller than others.

Can you inspect the dim lamps and see if there is any darkening of the bulb glass envelope?

It's not unheard of for new fixtures to burn off some oil, and it's also possible that that oil has deposited on the lamp.  You can try to clean your old lamps with alcohol wipes (like from a first-aid kit).  Make sure you don't touch the glass with your fingers.

Bench-focusing a Source 4 can affect the location and intensity of the hotspot, and also the overall intensity of the light.

It is also totally possible that you have a HPL750 that is defective.  If this is the case, It's likely that this bulb will burn itself out very quickly.

Do all 6 units have the exact same type of HPL 750W lamp?  There are extended-life HPLs that have slightly warmer color temperatures.  This could cause some bulbs to appear duller than others.

Can you inspect the dim lamps and see if there is any darkening of the bulb glass envelope?

It's not unheard of for new fixtures to burn off some oil, and it's also possible that that oil has deposited on the lamp.  You can try to clean your old lamps with alcohol wipes (like from a first-aid kit).  Make sure you don't touch the glass with your fingers.

Bench-focusing a Source 4 can affect the location and intensity of the hotspot, and also the overall intensity of the light.

It is also totally possible that you have a HPL750 that is defective.  If this is the case, It's likely that this bulb will burn itself out very quickly.

Thanks for the reply Paul....

Do all 6 units have the exact same type of HPL 750W lamp? There are extended-life HPLs that have slightly warmer color temperatures. This could cause some bulbs to appear duller than others.

- yes they are all the same.
- Being they are all the same (including the new one) this most likely is not the cause


Can you inspect the dim lamps and see if there is any darkening of the bulb glass envelope?

- there isn't really any darkening on the bulb, but there is some slight white clouding... assuming its on the outside so I will clean them.

It's not unheard of for new fixtures to burn off some oil, and it's also possible that that oil has deposited on the lamp. You can try to clean your old lamps with alcohol wipes (like from a first-aid kit). Make sure you don't touch the glass with your fingers.

- ok I will clean them to be sure that there is not oil residue burning on the bulb itself.... but I am getting concerned that they are still creating a noticeable order.

Bench-focusing a Source 4 can affect the location and intensity of the hotspot, and also the overall intensity of the light.

-I knew the focusing altered the hotspot, but didn't think it would make much over all effect on the intensity.... at least to the amount of difference I'm seeing...

It is also totally possible that you have a HPL750 that is defective. If this is the case, It's likely that this bulb will burn itself out very quickly.

- all six are at about the same intensity which is why I would not have noticed this when I installed them until I had something to compare to.... which I have now....

I think you're dealing with two separate issues:

To fix the odor issue, turn the lights on at full for at least consecutive 4 hours.  That will definitely burn off anything that's smelling.  If you're still getting an odor, call the dealer that sold you the lights.

It's likely that your new HPL750 is defective.  Bad lamps are just as likely to be "too bright" as they are to be "too dim".  To confirm this, try moving your new lamp into a different fixture.  If the brightness follows the lamp, you know that's the problem.  Try swapping in a different (new) HPL750 and report back.

Ok update, the odor finally has stopped... so I guess it just needed the right number of 'burn hours'.... the intensity was corrected with the combination of cleaning the bulb and re-focusing it.... thanks for further my education.