A dip into the DP is always worth while - I do it every day. The DP Review, I mean. The go-to website that got me up to speed with digital photography when I was still making my own wet plates...
That is only partially true - I never made wet-plate shots, except when I sneezed into a film holder one time. And then there was this one time with a petri dish...but that is beyond the scope of this column. The point today is that DP Review have linked onto a very good article regarding the quality of LED light sources, and how this is measured.
You really would benefit from reading the whole thing, but a précis tells us that there are Sekonic spectrometers available that can read a constant source and predict how well it will reproduce colours. Not just the basic level of illumination - the actual reproduction it will give for individual colours. This was way new news for me...
There are basic meters that split the spectrum into 8 bands and read out the reproduction of the colours as a percentage figure - and sunlight seems to score well into the 98% range all over - good going, Sol. There are industry-standard meters that slit it into a further set of bands that will let television studios cope with odd reds and skin tones better.
The article points out that these figures are frequently quoted in advertisements by LED bank manufacturers to tout their wares, but that the figure quoted may be an
average of the eight or more bands and there may be some real deficiencies buried in the measurements. Caveat lux, as it were.
Now I am wondering where I can get hold of one of the Sekonic spectrometers to try out my studio lighting. I have never had cause to complain about it yet, but being content with your lot in life is not what photography is all about, eh?
