There is always a lot of misunderstanding with CCT (colour Temperature, and CRI) with regard to LED lights. This might give some insight
Colour temp is the apparent colour of the light, CRi is a measure of the colour spectrum - a picture grabbed off Wiki highlights the spectrum difference between an incandescent lamp (full spectrum) and a fluorescent which is missing parts of the spectrum
Most LED lights including even expensive dive lights are quite rudimentary (with their light outputs) Remember the digital sensor on a camera (or film emulsion) "sees" colours differently to our eyes
In the TV lighting industry (my job) we've been using LED lights since 2010 when they first became good enough. We've moved away from CRI as a measurement and over to TLCI (television lighting consistency index) because that's more relevant to camera's. The higher the TLCI - the less colourisation work in post. There are only 2 manufacturers (both European) that make high TLCI units (98-99%). We have to be able achieve High TLCI at any given Colour temp.
Simply put. if you put a red colour filter in from of a tungsten light, the light from an LED light set to red and at 3400 CCT would appear exactly the same to the camera.
We use variable white light (variwhite) so we can adjust CCT from around 2500K upto 8500K to allow them to be used in any circumstances
To do this we will have 2 different dedicated arrays. 1 warm white, and 1 cool white,. mixing these together allows us to get the complete CCT range.
But this is only half the story.
LED's have lots of missing colour spectrums
So as well as the 2 white arrays, we have an additional 5 other dedicated colour arrays. Red, Blue, Green, Lime Green and Amber - Green is the weakest frequency for LED hence two.
So in order to generate white at 5600K with a full colour spectrum (high CRI/TLCI) we are mixing the outputs from 7 different arrays together
We use only the top 0.1% of arrays produced, and then there are complex algorithms running which ensure the output is repeatable between different fixture and takes account of the LED degradation from age/use (pretty much 20,000 hrs is the limit before is all starts drifting)
By contrast your divelight/video light will have a single array of some mixed colours and perhaps a and additional red boost but the variance between units of the same manufacturer can be different.
On top of that power and Lumen outputs need to be taken with a truck full of salt. Unless you've got a test bench, can you disprove their claims?
You should know that heat is a huge issue, not only at teh back of the array, but from the front. There needs to be a collimator and lense on the front of the array, these heat up massively due to friction from teh photons - so design and material choice is paramount, then reflector design and teh main lense design come into play.
Put a light meter in front of one of these lights and you'll be disappointed with the results.
For the diver - then whats the answer? None really - you won't be able to tell until you see the results on your camera. Just be aware that lots of claims by the lighting manufacturers are quite creative...
Colour temp is the apparent colour of the light, CRi is a measure of the colour spectrum - a picture grabbed off Wiki highlights the spectrum difference between an incandescent lamp (full spectrum) and a fluorescent which is missing parts of the spectrum
Most LED lights including even expensive dive lights are quite rudimentary (with their light outputs) Remember the digital sensor on a camera (or film emulsion) "sees" colours differently to our eyes
In the TV lighting industry (my job) we've been using LED lights since 2010 when they first became good enough. We've moved away from CRI as a measurement and over to TLCI (television lighting consistency index) because that's more relevant to camera's. The higher the TLCI - the less colourisation work in post. There are only 2 manufacturers (both European) that make high TLCI units (98-99%). We have to be able achieve High TLCI at any given Colour temp.
Simply put. if you put a red colour filter in from of a tungsten light, the light from an LED light set to red and at 3400 CCT would appear exactly the same to the camera.
We use variable white light (variwhite) so we can adjust CCT from around 2500K upto 8500K to allow them to be used in any circumstances
To do this we will have 2 different dedicated arrays. 1 warm white, and 1 cool white,. mixing these together allows us to get the complete CCT range.
But this is only half the story.
LED's have lots of missing colour spectrums
So as well as the 2 white arrays, we have an additional 5 other dedicated colour arrays. Red, Blue, Green, Lime Green and Amber - Green is the weakest frequency for LED hence two.
So in order to generate white at 5600K with a full colour spectrum (high CRI/TLCI) we are mixing the outputs from 7 different arrays together
We use only the top 0.1% of arrays produced, and then there are complex algorithms running which ensure the output is repeatable between different fixture and takes account of the LED degradation from age/use (pretty much 20,000 hrs is the limit before is all starts drifting)
By contrast your divelight/video light will have a single array of some mixed colours and perhaps a and additional red boost but the variance between units of the same manufacturer can be different.
On top of that power and Lumen outputs need to be taken with a truck full of salt. Unless you've got a test bench, can you disprove their claims?
You should know that heat is a huge issue, not only at teh back of the array, but from the front. There needs to be a collimator and lense on the front of the array, these heat up massively due to friction from teh photons - so design and material choice is paramount, then reflector design and teh main lense design come into play.
Put a light meter in front of one of these lights and you'll be disappointed with the results.
For the diver - then whats the answer? None really - you won't be able to tell until you see the results on your camera. Just be aware that lots of claims by the lighting manufacturers are quite creative...
