Paul C. Buff, Inc. Technical Forum

i'm a believer...
i attended a studio lighting seminar hosted by Light Rein.
all their SBs had an eggshell (made by Light Rein) mounted to control spill.
very wonderfull ($$$) tools these eggshells (20, 40 , 60 degrees).
anyhoo-i see the PLM (silver) is advertised as outputting a soft narrow light source equal to a 40 degrees grid.
40 degrees for a main/kicker, that's about right for a me for most uses.
i also see PCB has actual grids for their SBs/OBs. has anyone checked a siler PLM against a gridded SB to see if spill is about same?

PCB-are you planning to add a couple more sizes to your grid line up?
cheers,
Paul

I do not have a direct comparison at hand, we are working on those, the silver PLM (no diffuser) has a very sharp fall off once it hits the 40 degree mark. Spill outside of that is virtually non exixtent. We do not currently have any plans for other grids for the softboxes.

The quality of light is so radically different between a PLM and a gridded softbox that it's hard to put into words.

An 86 inch PLM is about 6 foot across on the front. Without a cover, if you put it 6 foot from your subject, it looks a lot like daylight on a slightly hazy day, the light is almost totally collimated, and the subject will cast a pretty well defined shadow on a background 6 feet behind them. The best way to think about it is that each part of the PLM shines a single ray of light straight ahead. Block that ray, and you "punch out" a subject shaped shadow in the "ray bundle"

A 6 foot octo with a 40 degree grid divides the octo up into a bunch of little squares, each square radiating light over a 40 degree cone. At 6 feet away, that 40 degrees is a touch over 4 feet on the subject. So, backtracking back to the light, a 4 foot section of the light face has squares that can reach any point on the subject, and you still get a pretty soft light. And outside the 40 degrees, the light "feathers" off, while the PLM is almost a "chop", like a big wide "spot". (At a distance equal to the light diameter, a 40 degree grid also cuts a full stop of power. A 30 deg kills 2 stops, an 20 deg over 3 stops).

Which begs the question, hey Buff guys, when are you bringing out grids for the PLM? Grid over the sock would be just the thing. I'd buy a couple of 40s.

I'd like to see the same thing...it should put out light that's fairly close to a gridded octa (maybe something like a fluffy cloudy sky vs. the silver PLM's sunlight :-)
Cost would be fairly high given the size...probably the same price as the PLM or maybe more...

I wanted something softer than either a silver PLM or a gridded Octa, but wanted more spill control than a plain umbrella or flat softbox. The 86" white PLM with the backing cover seems to be just the trick. Parabolic shape doesn't really focus like the silver, but it does enough to be useful for spill control. I was pleased to see that the cover is silver-lined, which wasn't mentioned in the item description; I'm sure this helps.

Just got mine a couple weeks ago, first impressions are very positive; used close to the subject, it gives very soft light and I can keep it from blowing out the room or a nearby backdrop.