Paul C. Buff, Inc. Technical Forum

With traditional umbrellas I've always had at least a minimal reflector on my strobe to direct the flash into the umbrella.

I've decided to try the PLM with the inline speedring which makes this theory impossible.

I assume this isn't a huge problem or PCB wouldn't make them but I can't help but fear the bulk of my light is going out the side instead of into the PLM.

Does anyone have any pics or vids of proper setup or input on my fear that this mounting method has light efficiency issues?

You don't have to use a reflector to get excellent efficiency with a PLM. If you want to see how much spill you're getting just take a picture of the PLM itself and the surrounding area.

If you don't want any side spill, PCB sells an umbrella reflector that prevents it. You would have to mount your PLM using the umbrella hole to use this or any of their reflectors with a PLM. But the issue is control of the light, not efficiency. PLM's are very efficient with a bare bulb. If you use anything more than the umbrella reflector you may actually reduce the efficiency by preventing the light from hitting the outer portion of the PLM. Here again, you could tell by taking a picture of the PLM. If you stop down significantly it's easy to tell where the light is going.

If the PLM is assembled and mounted properly (i.e. with the flash tube right at the edge of the fabric opening), then there will be little spill. As Itwiberly said, you can take a photo to see how much light spills. Generally, the bulk of the light will come from the front on the silver PLM's. With the white, it is possible to "defocus" the light (which really isn't defocused on white, as white cannot focus) to move the tube inside the open area of the umbrella, thus reducing spill.