Watch THIS Before Buying a Video Light! (CRI, TLCI, TM-30, SSI Explained)

Never knew I wanted to know this, but now I know it and I am forever grateful.

Hey Gerald, thank you very much for this video. My name is Tony Esposito, I am the Co-Chair of the IES Color Committee that developed and maintains TM-30. Thank you for your discussion of TM-30. I wanted to provide some additional information for you and your audience if you don't mind:

- Color fidelity measures, like CRI and Rf, are not measures of "accuracy", but instead how SIMILAR (i.e., how close in color space) your light source renders color compared to a standardized reference source at the same CCT. Depending on the CCT of your light source, that reference source will be a Planckian Radiation, a mathematical model of daylight, or a blend of the two.
- Rg of 100 is not "spot on" unless your Rf is 100. With an Rg of 100 and an Rf less than 100, some colors will be oversaturated and some will be undersaturated.
- As a matter of clarity, describing Rg of 100 as "spot on" implies that an Rg of 100 is always the desirable target. This isn't true. Research shows that people tend to light color with an increase in saturation, so sometimes an Rg greater than 100 is warranted. Keep in mind that most commercial light sources desaturate red colors, which people tend to dislike. Edit: you later describe Rg 100 as being the ideal, again, which isn't exactly right. People tend to prefer an increase in saturation, especially in red.
- The last number in the year is indeed the year. TM-30-15 was published in 2015 and TM-30-18 was published in 2018. There was a big change to Rf--the scaling factor was changed--between these two versions. TM-30-15 Rf will be incorrect. Any version of TM-30 after 2015 is good.
- For finding spectral matches, SSI is only really useful when it is very high, because when it is low is doesn't help you understand "how" the SPDs are different. That's why you need to compare the SPD's visually. Importantly, not all differences are created the same (for the purpose of creating a visual match), which SSI also doesn't tell you. If a spectral match is desired, the best course of action is to find two sources with the same CCT and with very high color fidelity (or SSI). Overall, my point is that for the purpose of matching SPDs, I don't see SSI being significantly more useful than Rf because you still need to visually compare SPDs when SSI isn't very high.

It is not clear what a lower SSI score does to the actual image quality.

TM-30 would be great for trying to find lights for household use that have a perceived cleanness, yeah? Is it only a measurement that film/video lights advertise?

No wonder this light is quite poor in term of color similarity. 73 score for tungsten is very low. That is what I find with this light. Very green yellow tint for 3200k.

Thank you so much for making this!

What an amazing video, learned alot for real. I run a fine art printing shop specializing on reproducing paintings and this is a great help when getting new LED ambient lights for the studio. Big Thanks!

Super helpful, thanks for helping me understand my color meter better.

Thank you so much ! You have managed to make sense of these cryptic lighting industry terms. This new found knowledge will allow me to make a more discerning buying decision. This is just the sort of facts that we as photography enthusiasts need at our fingertips. Well done !

Thank you for the well informative video.
Sekonic C-800: How to add new Memory Data to a pre-existing Memory Title other than the last one created?
All newly saved memory data seem to end on the last created Memory Title. This is regardless of the selection on the Memory Title folder. Selecting and Recalling a Memory Title doesn't work for this feature. I tried the C-800 Utility on macOS, but it doesn't allow copying and pasting memory data in any tabs.

The User Manual doesn’t address adding new Memory Data to a pre-existing Memory Title.
Any help would be greatly appreciated.

Sekonic C-800
F/W 20-11-11 (860B)

Amazing Video! You've helped me a lot. Thank you.

Indeed, it's a very informative and helpful guide. Thank you

This is why I don't like CRI and I wish I never discovered it in a small way. Since then for my recordings, I'm torn on changing my GU10 bulbs for my studio to either Philips 4000k CRI97 or Philips 6500k CRI90. The reason why I'm considering 6500k is because I have two PC monitors and a Sony BVM (CRT) that are approximately 6500k so it makes sense. But then apparently I'll get worse colour overall at CRI90. I can put "night mode" on my PC to help if I do go for the 4000k bulbs but the CRT, or other gaming handhelds won't be as easy to adjust and then they will look a lot cooler than it should be. Agh! Sony FX3 user by the way! 😊

The deep end 😂

The first problem for me is how much light a given light puts out e.g by setting my flash meter to 24fps iso 400 i can then get an F-stop and if I measure 1 meter from the source it starts making sense e.g my 660led bicolour light measures f4 + f4 and f5.6 both sides on full. My keylight can do f16 admittedly with a reflector about 2 stops (f8) less in a softbox.

It starts to give you a handle on where the lights can be placed, if the cri and light mix is bad then there is always black & white :~)

for those of us who can't buy the meters...is there software that measure something similar off an image?

Uff...now I better understand why some indie budget strapped filmmakers go for black and white 😬

Does Color Meter also measure Light (Exposer) or work as a Light Meter?

Which budget friendly Light Meter would you recommend?

I’m Gerald Undone and my TM30 trucks your TLCI!