Quick question. I own a six bank cool light. And I ve rented a kino before. Checking my footage there seems to be a difference in the quality of light between the two of them. Can anyone tell me what the major differences are between the kinos versus the cool light tubes.
cool light tube versus kino tube
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Chris Santucci
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Color rendering index, with Kino being 95 and Coollights being 87.
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Cool Lights
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Actually its 88 is our typical CRI, poster 2 is leaving out the ">". It says ">87" on many of our product pages. CRI is something some people fall back on when they really don't know or weren't involved, but there could be lots of things.
For example, you told us before here:
http://www.dvxuser.com/V6/showthread.php?p=1608612#post1608612
you were renting the 4 foot kino fixtures.
That's an apples and oranges comparison. You were mainly looking for superior output and 55w tubes will do that but its a different look. Light from the 4 foot T12 fixtures will be a bit different, perhaps softer since its a bigger tube. Some like 55w tubes and some prefer 4 foot tubes. I remember a recent thread here somewhere and a few people chimed in saying they liked 4 foot tubes and thought the Diva type 55w was a harder light. Of course, its a smaller tube relative to the 4 foot. The larger the source, the softer.
And there are other things that can account for the differences as well. Different cameras, different settings, different white balance, different color temperatures and your camera sensor reacting differently to those, some other light source besides the flo (and perhaps a different color temp) in one footage that wasn't in another, etc. We don't know all your details because none of us were there and you didn't give any details.
Anything that anyone gives here is speculation because we can't see what you're seeing nor do we know all the details and background of all the footage.
In general it would be better to compare the footage from something shot with a diva/55w tubes with ours and identical camera settings and conditions if you want to make valid comparisons between a kino 55w tube and ours. This kind of comparison you made can really only say something like "I like a Kino 4 foot tube better than a Cool Lights 55w tube". Cool Lights doesn't have a 4 foot tube so nothing to compare there apples to apples-wise.
In any case, I don't have any complaints about Cool Lights tubes. You're two recent threads are the only thing I've seen on this and I have no email from you about an issue related to our tubes. If we had received mass comments, we would have changed the recipe a long time ago. CRI 90 and above is not hard to reach but we've gone into why we didn't do that before and it has nothing to do with costs. CRI 95 won't cost us anything else but it will cost you some lumen output.
CRI 95 is mainly interesting when you're using real film and that's what Kino bulbs were originally intended for was film. Back in '89, when they started, film (in motion and stills) was far more prevalent than today and there was no such thing as "DV" or mass indy movement with digital film replacement in video or stills. Minus green (magenta) filters were the only thing film crews had before that to do the job of taking out green (from fluorescent and other discharge lighting) and improving CRI. They found that by boosting the magenta (opposite green on color wheel) in the bulb phosphor you can effectively do the same thing as the minus green filter was doing. Since film has no natural ability to balance out a green spike in a flo bulb, they needed all the help they could get. Today its no big deal to boost magenta phosphors in a tube and its done all the time. Its mainly not done though to a big extent (especially in commercial lighting) because it does limit output lumens. CRI 82 is becoming more and more common in commercial lighting because its a good point where you have some not bad color rendering and also not bad output. The higher you go toward CRI 99, the more output you limit. Want to make up for lack of output with a higher CRI bulb? Overdrive the bulbs like Kino does on some of their fixtures.
Digital video and still cameras have no problem with reasonable CRIs however (and 88 to 90 is very reasonable and not that much lower than 95) given that their white balance circuitry can take care of whats going on not only in the red / blue axis of color temperature but also the green / magenta axis as well which is more indicative of CRI. But you have to give that circuitry a chance and you won't do that using preset 5600K on your camera. Custom white balance is always preferable to stock settings.
Osram calls their 55w tube CRI 90 but the one we tested was CRI 88. The particular Cool Lights one we tested at that time was also 88. We tend to underreport our specs actually and the current batch is closer to 90 these days, with the new phosphors we're using from Japan. You can see the old test reports on our website in my blog. I haven't posted any of the latest ones and I'm not sure anyway what 2 points difference really makes for digital media. Osram 55w are probably the most used 55w bulbs in media production and are found in tons of television studios around the world. No one is complaining there either of an average CRI 88 bulb.
For example, you told us before here:
http://www.dvxuser.com/V6/showthread.php?p=1608612#post1608612
you were renting the 4 foot kino fixtures.
That's an apples and oranges comparison. You were mainly looking for superior output and 55w tubes will do that but its a different look. Light from the 4 foot T12 fixtures will be a bit different, perhaps softer since its a bigger tube. Some like 55w tubes and some prefer 4 foot tubes. I remember a recent thread here somewhere and a few people chimed in saying they liked 4 foot tubes and thought the Diva type 55w was a harder light. Of course, its a smaller tube relative to the 4 foot. The larger the source, the softer.
And there are other things that can account for the differences as well. Different cameras, different settings, different white balance, different color temperatures and your camera sensor reacting differently to those, some other light source besides the flo (and perhaps a different color temp) in one footage that wasn't in another, etc. We don't know all your details because none of us were there and you didn't give any details.
Anything that anyone gives here is speculation because we can't see what you're seeing nor do we know all the details and background of all the footage.
In general it would be better to compare the footage from something shot with a diva/55w tubes with ours and identical camera settings and conditions if you want to make valid comparisons between a kino 55w tube and ours. This kind of comparison you made can really only say something like "I like a Kino 4 foot tube better than a Cool Lights 55w tube". Cool Lights doesn't have a 4 foot tube so nothing to compare there apples to apples-wise.
In any case, I don't have any complaints about Cool Lights tubes. You're two recent threads are the only thing I've seen on this and I have no email from you about an issue related to our tubes. If we had received mass comments, we would have changed the recipe a long time ago. CRI 90 and above is not hard to reach but we've gone into why we didn't do that before and it has nothing to do with costs. CRI 95 won't cost us anything else but it will cost you some lumen output.
CRI 95 is mainly interesting when you're using real film and that's what Kino bulbs were originally intended for was film. Back in '89, when they started, film (in motion and stills) was far more prevalent than today and there was no such thing as "DV" or mass indy movement with digital film replacement in video or stills. Minus green (magenta) filters were the only thing film crews had before that to do the job of taking out green (from fluorescent and other discharge lighting) and improving CRI. They found that by boosting the magenta (opposite green on color wheel) in the bulb phosphor you can effectively do the same thing as the minus green filter was doing. Since film has no natural ability to balance out a green spike in a flo bulb, they needed all the help they could get. Today its no big deal to boost magenta phosphors in a tube and its done all the time. Its mainly not done though to a big extent (especially in commercial lighting) because it does limit output lumens. CRI 82 is becoming more and more common in commercial lighting because its a good point where you have some not bad color rendering and also not bad output. The higher you go toward CRI 99, the more output you limit. Want to make up for lack of output with a higher CRI bulb? Overdrive the bulbs like Kino does on some of their fixtures.
Digital video and still cameras have no problem with reasonable CRIs however (and 88 to 90 is very reasonable and not that much lower than 95) given that their white balance circuitry can take care of whats going on not only in the red / blue axis of color temperature but also the green / magenta axis as well which is more indicative of CRI. But you have to give that circuitry a chance and you won't do that using preset 5600K on your camera. Custom white balance is always preferable to stock settings.
Osram calls their 55w tube CRI 90 but the one we tested was CRI 88. The particular Cool Lights one we tested at that time was also 88. We tend to underreport our specs actually and the current batch is closer to 90 these days, with the new phosphors we're using from Japan. You can see the old test reports on our website in my blog. I haven't posted any of the latest ones and I'm not sure anyway what 2 points difference really makes for digital media. Osram 55w are probably the most used 55w bulbs in media production and are found in tons of television studios around the world. No one is complaining there either of an average CRI 88 bulb.
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