High Efficiency Modifier

[mike weeks]

Enough people with enough knowledge here so I wonder what the answer is?

I need to find the most efficient (i.e. highest output power) modifier that gives nice soft lighting with a diagonal (or diameter) in the 70-100cm range with a Bowens S fit and before anybody says I know that high effiency and soft do not generally go together

Mike

 

[Garry Edwards]

A large white reflective umbrella that's really deep is probably your best bet - the so-called parabolic ones maximise efficiency in that they minimise light spread.
A silver one of the same size and design would be even more efficient, but a little more specular.

In a nutshell, 'efficiency' is mainly about how much light is directed ONLY towards the subject
"Softness" is about the relative size of the modifier in relation to the size of the subject so, as the inverse square law applies both to size and to loss of light, if you can get your modifier twice as close it will be 4x as efficient and 4 times as big - approximately.

 

[mike weeks]

Cheers Garry, that was pretty much the area I was looking but nice to have it confirmed.

Mike

 

[HoppyUK]

As Garry said really. You can make a standard brolly into a parabolic by putting some 'darts' up the sides - run a sewing machine up the folds.

Maybe try something like a deep octa, with/without diffuser panel/s? Lencarta Profold 85cm octa is deep, getting on for parabolic https://www.lencarta.com/studio-lighting/softboxes/profold-softbox/95cm-octa-folding-pro-softbox. It's my favourite portrait light though I've not done any measurements on efficiency.