Quasar LED Kino Flo Conversion

I would be interested to see the results of such a comparison. There's a lot of talk about LED replacing, particularly, fairly low-powered (as in not many kilowatts) soft sources such as fluorescent. On paper the comparison is not that convincing, since most current white-emitting LEDs, especially those with reasonable colour quality, are only about as efficient as fluorescent. And they're much, much more expensive.

LEDs can often look subjectively brighter because they are smaller point sources and often project their light into a smaller angle. While the likes of Litepanels do produce a type of projecting soft light that's rather characteristic and interesting, if you're after traditional soft light you often want neither of these things.

Cautious evaluation of the exact light pattern produced, and the intensity at various points, would be necessary for a reasonable comparison.
P
 
www.cinemills.com/product/led/sufa-bullet this one may change your mind Phil :) Was on a set where they rigged it on a process trailer, using 2 to replace to 4k para running on inverters. Also seen used as primary sources on new Disney XD pilot shot here in ATL. Let's hope LEDs get there soon 4k power on a putt-putt? Sign me up.
 
Well, OK, but to be fair that's a manufacturer's site.

One manufacturer of LED lighting - a respected manufacturer, whose products are widely used - once claimed that a device consuming forty real watts of power was equivalent to a 1K. The justification they were using was based on data from the LUMEN Coalition, an organisation set up to promote more efficient domestic lighting in the US. The key information they took from LUMEN is that an incandescent light develops 16 lumens per watt, and that the radiation pattern is broadly spherical. This a realistic set of numbers for a domestic 60-100W tungsten incandescent bulb. So, the 40-watt LED would equate perfectly well to a 1K, if there was such a thing as a 1K non-halogen tungsten and we put it behind a flag with a hole in it to approximate the LED's pattern. Obviously, this is completely absurd. It's nothing directly to do with these Quasar tubes but it serves to illustrate some of the problems that currently exist with the general understanding and specification of LED lighting and the way it is being promoted.

With a lot of these arguments, much of the difference is actually in the optical setup of the device, not the prime mover of photons. As such, a more reasonable comparison would have been to something like an HMI PAR, especially the Arrimax stuff. Theatre and event lighting people have been very familiar with the optical efficiency of PAR for decades, both in the form of sealed beam cans and the Source Four PAR. The LED array in the lights you link (and other things) is essentially a lot of tiny little PARs and it is very efficient, but it isn't anything like a fresnel.

I'm not here to make a better-or-worse argument for Cinemills' product versus anything else, but it's as well to be cautious. If you take that device to set and expect it to equal a 6K when, for instance, you punch it through diffusion, you will be disappointed. At 800W, it develops less than a seventh the power of the HMI, and LED is emphatically not seven and a half times more efficient than HMI. The very best stuff may be a bit better - perhaps a few tens of percent better - than HMI in term of raw luminous efficacy, and even that risks colour quality (which is a compromise factor with efficiency).

On the other hand, LEDs (from Litepanels up) have made it much easier to achieve that sort of penetrating softlight that is difficult to achieve without an array of individually-collimated emitters. It depends what you want. But it isn't a 6K.

Phil
 
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I hear you Phil but as far as the product we are discussing in this thread, the Quasar tubes incorporate diffusion into their design creating a source that is all but indistinguishable from a standard fluorescent tube. In practice I have found them to be punchier and it would not be surprising to me to learn that they are 40% brighter than a Kino tube. Presumably this is due to a tight spacing of the LED emitters to maximize output. Obviously this is a simple test to achieve. As far as the cost factor, as is often the case with LED's you pay a premium and these are more than 10x the cost of a comparable Kino tube, so no surprises there.
 
That's sort of the point - it's not really a simple test to achieve because it is highly dependent on the use case. You can easily side-by-side a 4x4 Kino with conventional tubes and again with these tubes and get an idea of how well they work in specifically that application, but we need to be very careful about phrases like "40% brighter". For a start, they emit only down one side, so they avoid the reflector losses of a fluorescent kino but there are (at least a few) applications where that would be a problem, or at least alter performance.

Achieving a 40% absolute efficiency benefit over fluorescent is... possible, barely. Just barely, depending how good the drivers are. Much of the benefit will be in the optical design.

It probably sounds like I'm splitting hairs, but there's a lot of steaming bovine ordure being put out about this sort of thing. Witness the people who think 0.8K = 6K thanks to the wonders of LED tech. There may be nothing wrong with any of it, but I'd prefer to see LED technology promoted on its own merits, as opposed to these often-dubious claims of equivalence with something wildly different.

P
 
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Phil Rhodes said:
For a start, they emit only down one side, so they avoid the reflector losses of a fluorescent kino but there are (at least a few) applications where that would be a problem, or at least alter performance.
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Yes, a few applications, like hanging tubes as a set element where you need to see the complete cylinder and/or have light emit from the complete circumference of the tube. Last time I did that myself was over 20 years ago. When I have tubes pulled out of a fixture, it is to mount them in or above cabinets, under a bar or behind glassware etc behind a door or a pillar etc. In those applications the 180 degree capability of the Quasar's will suffice. In many instances it becomes necessary to run paper tape down a tube as a cutter, further reducing the surface area.

I prefer to think about these things in terms of practical use rather than theoretical. If I had a shoot where I need a 360 degree emitting tube, I can always spec Kinos.
 
CharlesPapert said:
Yes, a few applications, like hanging tubes as a set element where you need to see the complete cylinder and/or have light emit from the complete circumference of the tube. Last time I did that myself was over 20 years ago. When I have tubes pulled out of a fixture, it is to mount them in or above cabinets, under a bar or behind glassware etc behind a door or a pillar etc. In those applications the 180 degree capability of the Quasar's will suffice. In many instances it becomes necessary to run paper tape down a tube as a cutter, further reducing the surface area.

I prefer to think about these things in terms of practical use rather than theoretical. If I had a shoot where I need a 360 degree emitting tube, I can always spec Kinos.
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Charles, this is NOT what Phil is saying - he's simply reacting to an avalanche of overblown claims spewed left and right nowadays. There is a shot in the Cinemills video where they film through 2 diffusions about 6 ft from a window of a trailer. If that light was indeed 6k equivalent there would be super nova in that trailer giving birth to its sister star.
 
I was responding to the specific point Phil was making about this "use case", not about the general state of LED manufacturers and their claims. This is a thread about the Quasars, and as I see it (and correct me if I'm wrong), Phil suggested that a blanket statement of those units being X amount brighter is not applicable in all circumstances. Discussions of LED's being single-point sources and their projection angle are not applicable to their Quasar tubes since they incorporate diffusers into the design.

Unlike many situations where LED fixtures are being pitted by the manufacturers against legacy units in a non apples-to-apples fashion, this is a fairly clear-cut comparison since the Quasar tubes are very close in dimension, output light pattern etc. So it really shouldn't be that complicated to demonstrate a real-world representation of their relative output that should hold true for the majority of users and use cases.

For me, extra oomph with these tubes is icing on the cake and something I hadn't even paid attention to. I'm personally much more engaged at the ability to have fine dimming control throughout their range. After years of rifling through the settings on Kino ballasts "give me three high--now four low--now three low" and resorting to bobanet and ND cuts, I'm done.
 
the Quasar tubes are very close in dimension, output light pattern etc
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Well, that's sort of the question - are they? I raise this simply to encourage people to do some sort of point-by-point emission mapping, rather than just waving a meter in the hottest part of the beam and saying "oh look, it's way brighter." I can do that with a flashlight. My suspicion would be that they aren't really 180-degree emitting in anything like the same way a fluorescent tube is.

In many applications this will actually be very helpful as more of the light will be going where it's useful, and this is not necessarily a criticism. I don't think anyone really disagrees here. I'm just advocating a cautious (very cautious) approach to these sorts of comparisons. Yes, of course, the dimming is useful.

P
 
StrobelPhotography said:
How much brighter they are then kino's still eludes me. Numberically, that is. If anyone in LA has a 4' 4bank and wants to do a test I'd be down. Just let me know, I think it would be interesting to compare the two in the flesh.
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Well, I hope someone takes you up on this offer... and would love to hear about results. I appreciate you sharing your enthusiasm for the Kino's retrofitted with QS. If I can add a bit of extra punch with the dialable wb choices of these led's... I personally think it's worth the extra $
 
And an fyi for Charles and others.... I sent Quaser an email about the different base tubes used in the Diva's and his response was "We do not yet make a SG11 base LED but we have begun working on it"
 
markfpv said:
Well, I hope someone takes you up on this offer... and would love to hear about results. I appreciate you sharing your enthusiasm for the Kino's retrofitted with QS. If I can add a bit of extra punch with the dialable wb choices of these led's... I personally think it's worth the extra $
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Yeah, thx, I'd really love to have them side by side. I'll def make a video to show the results. Also I'd like to illustrate the differences as well if there are any noticeable differences in spread and softness etc.

now im thinking I should've gotten the dial able versions of the color temp. Haha seems everybody's hot on that feature. Oh well. I'm talking to Steve about my second one, I'll add it on that one maybe.

Im truly enjoying this light tho, I pulled out the old mamiya c220 tlr tonight and coerced my lady and some of the household pets to pose for New Years portraits. Simple clamshell setup. Not sure how they'll turn out based on my exposure readings but they looked pretty nice in person. I'll share if anything turns out.
 
I just wanted to update this thread with some lightmeter readings. I wasn't able to locate anyone with an actual 4x4kino so i pulled their numbers from the photometric chart. My test was very unscientific. I put the light up at 6ft from the ground around my nose level, put a tape measure on the floor and tried to be as consistant as possible.


kino numbers are: 2ft=476fc, 4ft=158fc, 6ft=76fc, 8ft=45fc, 10ft=29fc, 12ft=21fc, 14ft=16fc ........and then I ran out of space.

quasar led 4'6bank:2ft=1300fc, 4ft=410fc, 6ft=220fc, 8ft=140fc, 10ft=97fc, 12ft=64fc, 14ft=50fc
 
That's a little confusing, brother...I would have recommended saving two of the tubes in your array to make it apples to apples. Even with that factored in, you have the Quasars coming in roughly twice as powerful as the Kinos, and as much as I'm a fan of the Quasars I'm not sure I'm quite believing that measurement. Next time we are prepping a show I'll have my gaffer run a test and post the findings. Regardless...great instruments.
 
If those numbers are close to accurate - then I'm definitely sold (even understanding it's 6 vs 4). Would love a follow-up Charles! I'm also still waiting for the tubes to replace my Diva's bulbs...they can't be made soon enough.
Thanks Strobel for sharing (no matter how unscientific) :-)
 
CharlesPapert said:
That's a little confusing, brother...I would have recommended saving two of the tubes in your array to make it apples to apples. Even with that factored in, you have the Quasars coming in roughly twice as powerful as the Kinos, and as much as I'm a fan of the Quasars I'm not sure I'm quite believing that measurement. Next time we are prepping a show I'll have my gaffer run a test and post the findings. Regardless...great instruments.
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DOH! Ok, I pulled two bulbs to make it apples to apples. (still looking fwd to your findings Charles)

kino numbers are: 2ft=476fc, 4ft=158fc, 6ft=76fc, 8ft=45fc, 10ft=29fc, 12ft=21fc, 14ft=16fc

quasar led 4'4bank:2ft=1000fc, 4ft=320fc, 6ft=170fc, 8ft=100fc, 10ft=73fc, 12ft=60fc, 14ft=50fc (surprised that the 12ft and 16ft are almost the same to the 6bank.)


 
These are $300 each? It would cost $1200 to load up a KinoFlo Diva not including any retrofit kit. Pretty expensive.
 
Where did you see / find the price? I have been waiting for QS - who have told me the SG11 base needed for the Diva might start shipping around the end of this month - to post prices on the tubes.
 
I went to cinegear the other week and came across a way better LED tube product. The Source MakerLED tubes have similar output, but contain two drivers and two circuits in each tube. They then have a harness that converts the 4 LED tubes into a 4 bank kino head feeder out, so you can use your existing head feeders. This terminates in a 2 channel hand dimmer that can plug into the wall, this allows you to dial in color temperature and brightness. You don't have to change the color of each tube and you can rig them high and still control them from the ground. Same price point too. Pretty great stuff.
 
Ryan, how is the color accuracy of the Source Maker tubes? Any comparative charts or specs?

As far as control, I've been using the Quasars in a DMX environment so that is covered...the distinction you are making is on changing the color balance?
 
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