Welcome to our community

Be a part of something great, join today!

Register Log in
  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Led mystery solved making way for high output fixtures.

Will this cause further throw from LED fixtures or just better efficiency/output?
 
It should provide for both. If I'm reading it right, it seems they constructed some special LEDs with separated elements so they could determine the cause of "droop". This "droop" has been the long-standing achilles heel for all diode-based lighting, including lasers. Essentially, what happens is as you increase the amount of power into a diode, you have rapidly diminishing returns to the point where it eventually creates no more usable output, only heat. Most LEDs have very sharp fall-offs into their droop zone.
 
Ahh...i have been wondering for a while why LED couldnt output higher intensity. Hopefully we can see 10K above equivalent light output in near future.

Rivai
 
The future of LED fixtures looks great, however not all do respond to the very HIGH demanding specs of Cinema/Photography use, were not only the CRI needs to be as high as possible but the actual light spectrum needs to be consistent and of exacting Colorimetric's Temperature readings, and have precise temperatures set at 3200k and 5600k all others can be a plus to some extents, but this two are primarily the standard and if not met then those LED's will have no market in our industries.


Hopefully not too far out from today we'll be able to announce what we are working on as far as LED technologies for the Industry and Business & Home use alike... ;)
 
Ketch, which LED in your experience meet the CRI specs as far as the unit that you ever tested. I know Arri L7 sure hit the spot, but what about other brand ? Briteshot ? Nila ? etc ?

Most claimed in their website hit CRI specs. But we can only know when it hits the street

Thanks
Rivai
 
CRI is one thing and you're in reality looking for any sort of spike across the spectrum.

I can't fathom LEDs from a buyers perspective. I've been using and investigating LED sources for 2 years now and there are a lot of options with varying levels of "usability". I think where LEDs lay industry wide is mostly due to a sense of mystery. Everybody in the world knows what a Baby 1K can do. However, any modern LED light is really a grab bag in terms of light quality and output. I have no clue where some LED manufacturers get their photometric data from. I've seen units compared to an 400w HMI and barely make it to what I consider a 70w HMI. I just don't get it.

I'm currently looking at and will be testing out Nila (Varsa and the new Boxer) as well as the Arri L7-C this coming week. I've actually had a bit of face time with these and they both have their pros and cons.

I'm one of these "weirdos" that likes to use newer lighting tech. Generally speaking, one thing that LEDs can do easily is produce a soft light. Many units provide a similar feel to a Kino Flo. I'm more of a light shaping guy and I like hard light that I can soften, spread, dim, etc..... Which is why the Nila are appealing over some of the other panel designs. They focused on high output narrow light that you can spread out via "holographic lenses" (etched plastic), which is actually pretty cool to me. The added functionality of Arri L7-C fresnel and very flexible color controls is very appealing as well. Although the L7-C is not as compact as the Nila Varsa.

Whatever is going to happen I'm putting together a 3 or perhaps 4 light kit to start with one of those two models. Might go up to a 3 light Nila Boxer kit if I love the light and need more punch. I need lights that travel well and that's also coming into play here. I'd like to stay relatively compact if I can.

I'm optimistic and pretty much know I'm going with Nila or Arri at this point. They are also both using some of the newest LED tech you can get in their fixtures.
 
Jeff - you never cease to amaze me when you put your Mr. Science hat on! LOL Will this development have a similar impact on phosphor lighting like the PRG stuff?

And Phil - I am one of those "weirdos" too. Can't see going back to the heat and power draw of tungsten.

And a general question - given that the weakness of LED is a color spike, will shooting a white/gray card and doing an auto-adjustmnent in RCX lead to a tint adjustment that will compensate for the spike?
 
RivaiC said:
Ketch, which LED in your experience meet the CRI specs as far as the unit that you ever tested. I know Arri L7 sure hit the spot, but what about other brand ? Briteshot ? Nila ? etc ?

Most claimed in their website hit CRI specs. But we can only know when it hits the street

Thanks
Rivai
Click to expand...


Rivai,

that is an easy question to answer, which I did so via buying my new LED's from B,B&S which are the Area 48 Soft, of which I created a Group Buy here: http://www.reduser.net/forum/showthread.php?97068-The-quot-LED-quot-light-Group-Buy

This of all LED's tested, (as to cover the needs for an evenly Soft Light Spread) from nearly all of them available to market as of today, this have offered me the best of all needs for Cinematography and Photography, while taking in consideration that the CRI, while important is only one of the main quality one must look on a LED fixtures, and Phil has made some great points, yet there is os much more hidden under the actual spectrums and color renditions of the LED fixtures, to insure proper continuos output in their respective color temperatures.

However, needs in each one must be considered when buying, so is budget and portability etc.
 
Unfortunately led can be a bit of a fallicy. To make leds more efficient and brighter they can narrow down the target frequencies to match the highest response sections of the human eye. Tri phosphor fluorescent also tries this. But our eyes see accross a much larger range, which means that color in led lit scenes can appear less than accurate compared to a wide frequency light like halogen etc used in art galleries. Happily it doesnt mean it wont look nice.

However, there is a technology I can not remember the name of at the moment, that the us military is funding research into. It is a led derivative that should be up to 100% efficient lighting source, many times more efficient than normal leds (though there is an Australian led lighting provider claimed 80% efficiency for years in a secret processes that seems strangely like my planned idea to get similar results). If this can be made to produce a suitable range of frequencies at high efficiencies you could get a halogen or tungsten like visible spectrum at a fraction of the power consumption. Of course, as it is aimed at lighting, there would likely be little development aimed at this wide spectrum use.

However, the Samsung Galaxy S4 screen uses a newer PHOLED design that is more efficient then the older oled one. I wonder if that is useful at all for light weight lighting for now compared to conventional led. Remembering that old Tom Cruze movie, I forget the name now, they used fluorescent or el panels with a Viper, for a nice inner city seedy urban decay look. But with a Dragon Epic/Scarlet or Canon, much better results should be possible with these new technologies.
 
Terry VerHaar said:
And a general question - given that the weakness of LED is a color spike, will shooting a white/gray card and doing an auto-adjustmnent in RCX lead to a tint adjustment that will compensate for the spike?
Click to expand...

Not necessarily. The issue is not color balance - it's the spike.

Materials don't just emit R or G or B. They emit in certain wavelengths.

For example: let's say you have a light with a big color spike in cyan area of the spectrum. But it emits very little actual intense deep blue near ultraviolet range.

If the light shines against a white piece of paper, the white balance will be "too blue".

If the light shines against a hypothetical ultramarine fabric that doesn't reflect cyan much, the white balance will be "not enough blue".

So it can be simultaneously "too blue" and "not blue enough" in the same shot.

This is difficult to correct without doing secondary color correction. And sometimes, there is just no info there because none of the light in the right wavelength for the ultramarine fabric to reflect made its way from the light to the sensor. So there is no color info there for your color corrector to emphasize.

This is a similar situation to why you can't always make one camera look 100% like another camera even if you shot raw on both cameras. If a sensor shot not just red or green or blue but 20 wavelengths (there are cameras that do that), then you'd have a chance!

Bruce Allen
www.boacinema.com
 
Bruce Allen said:
This is a similar situation to why you can't always make one camera look 100% like another camera even if you shot raw on both cameras. If a sensor shot not just red or green or blue but 20 wavelengths (there are cameras that do that), then you'd have a chance!

Bruce Allen
www.boacinema.com
Click to expand...

I was remotely involved in some rather thorought testeing of matrixes of different LED lights and cameras (RAW and others), and can subscribe to all of what you say...

This last part though begs a more philosphical/estethical question:
Is such a conformity at all desireable?
 
Gunleik Groven said:
I was remotely involved in some rather thorought testeing of matrixes of different LED lights and cameras (RAW and others), and can subscribe to all of what you say...

This last part though begs a more philosphical/estethical question:
Is such a conformity at all desireable?
Click to expand...

This refers to Phils comment. I think conformity is important for consistency on set. I've had the same make of LED panels look completely different. Spikes or not, that's not something you want to deal with on set, or in post. It should easier to match on set, so you can be more creative in post, instead of having to FIX mixed color fixtures (that should be matched).
 
Justin Chin said:
This refers to Phils comment. I think conformity is important for consistency on set. I've had the same make of LED panels look completely different. Spikes or not, that's not something you want to deal with on set, or in post. It should easier to match on set, so you can be more creative in post, instead of having to FIX mixed color fixtures (that should be matched).
Click to expand...



Nope...

I agree on the need of confor
ity between (at least the same brand of ) Lightsources. And like the tungsten/HMI divide as conform things.

What I was asking Bruce about is more the conformity between camera-brands

(despite not having seen two identica Epics so far... But that is a different story...)

Ah...
Don't wanna derail this great thread!

Sorry!
 
Bruce Allen said:
Not necessarily. The issue is not color balance - it's the spike.

Materials don't just emit R or G or B. They emit in certain wavelengths.

For example: let's say you have a light with a big color spike in cyan area of the spectrum. But it emits very little actual intense deep blue near ultraviolet range.

If the light shines against a white piece of paper, the white balance will be "too blue".

If the light shines against a hypothetical ultramarine fabric that doesn't reflect cyan much, the white balance will be "not enough blue".

So it can be simultaneously "too blue" and "not blue enough" in the same shot.

This is difficult to correct without doing secondary color correction. And sometimes, there is just no info there because none of the light in the right wavelength for the ultramarine fabric to reflect made its way from the light to the sensor. So there is no color info there for your color corrector to emphasize.

This is a similar situation to why you can't always make one camera look 100% like another camera even if you shot raw on both cameras. If a sensor shot not just red or green or blue but 20 wavelengths (there are cameras that do that), then you'd have a chance!

Bruce Allen
www.boacinema.com
Click to expand...

i guess I ddidn't phrase my question well. I totally understand white balance and color correction. But WB is based on shooting pure white or grey. If you do that in raw and run tthe eye dropper in RCX, it will balance and add a tint if necessary. My question is whether that tint will compensate for the color spike. In other words, is it a bit like running an audio signal through EQ to cut out the unwanted frequency?
 
Terry VerHaar said:
i guess I ddidn't phrase my question well. I totally understand white balance and color correction. But WB is based on shooting pure white or grey. If you do that in raw and run tthe eye dropper in RCX, it will balance and add a tint if necessary. My question is whether that tint will compensate for the color spike. In other words, is it a bit like running an audio signal through EQ to cut out the unwanted frequency?
Click to expand...

In short:
Nope, that will often not give a very delicate result...
 
Post wb'ing is probably the least comprehended noise and image degradation source.

If you use lightsources with spikes or where some frequencies are lacking/gone, there isn't a "push button" way to make that look like sunlight. It can look cool, fun and good, but not in a similar way as a full spectrum light...

And f you try to compensate that n post, severe and strange noise-artefacts should and would be expected...

Btw... I like LED lights... :-)
 
I like LEDs too, for the most part. I have a few panels that have gone "way green" and lack the hardness I want out of source. A few tungsten units, a few daylight flouros, and some other weird thigns.

I'm still banging my head on the wall testing, but for whatever reason I'm itching to have more LED lights in my kit. Studios I shoot at tend to have plenty of tungsten, but I need a quality compact kit that can travel. 1 to 3 cases for 1-4 lights.

Which is why Nila has attracted me. Built like tanks, punchy, and I looked at them through a scope and saw no green spike. Which was actually hilarious because at NAB I could point that sucker at nearby LED booths and see their whole story too.

I'm doing some IR tests next week. Quick and dirty. That Arri L7-C looks attractive. Just want something I can shape.

The nasty bit here though is you really do need to test everything on the LED front to fully understand what each manufacturer is offering. Which is time consuming. Most are happy to work with you and do demos luckily and you can certainly do a fair bit of testing at a place like NAB with everything on display.

I'd love to know other's thoughts on particular fixtures out there that have produced good results. There's far more "not so good" than good.
 
Gunleik Groven said:
Post wb'ing is probably the least comprehended noise and image degradation source.
Click to expand...

But when we shoot raw we aren't really "post wb'ing" are we? If we shoot a gray card under a tungsten light that is rated at 3200K and it turns out to be actually 2800K, by aligning the waveforms of all three sensors in RCX with the eyedropper on the card, we are not "post white balancing" as much as we are discovering the true color temp of the light. After all, with raw, WB is only metadata.

Now, if we do the same procedure but shoot the grey card under an LED rated at 5000K, the eyedropper will align the three (RGB) waveforms again - to give a true WB temp - but it might also change the tint value based on other colors present. So, I am thinking the tint adjustment will somewhat (but not perfectly) compensate for the color spike. Again - not the same as having a light with an even, full spectrum output but how far off would it be?
 
You must log in or register to reply here.
Back
Top