1x1 LED Gels?
 

I read that bi colour LEDs suffer from low power so I'm thinking to go for a daylight and GEL to get tungsten look. The problem is we do not have those in Singapore. Can you guys recommend what and where to get them? Do they come only slightly bigger that the 1x1 or in some kind of larger standard size to be cut?

I'm thinking of the F&V K4000 kit.
Thanks.

Re: 1x1 LED Gels?
 

My local camera shop was kind enough to let me cut to fit some CTO scraps that were laying around. You can also buy single sheets for as little as $5.

I found that 1/2 CTO, 3/4 CTO and Full CTO were most helpful. And it really helped to use about a 1/4 minus green gel (the purple one) in conjunction with CTO on the K4000.

I'm thinking of making some that attach with Velcro strips on the corners, but then again, gaff tape works just fine...

Re: 1x1 LED Gels?
 

I ordered two of these from B&H thinking they'd be a good alternative to clothes pegs:

http://www.bhphotovideo.com/c/product/757084-REG/Impact_3312_MK2_Universal_Filter_Holder.html
One arrived broken (at $39.95 not worth sending it back...) and the other doesn't tighten at all well and is a study in frustration so I DON'T recommend them.

Re: 1x1 LED Gels?
 

Ordered these and I'm pretty happy...

http://www.bhphotovideo.com/c/product/292678-REG/LEE_Filters_DTP_Daylight_to_Tungsten_Filter.html

Re: 1x1 LED Gels?
 

Sean - after reading the post and the part about using gel, maybe an alternative like this. Reason being, my experience with using gel is it seems to really suck up a lot of lumens.

Just before going on vacation I was looking for a portable camera light and wound up getting a Comer. What was very interesting is that it has a mix of LED colors. One row of LEDs is warm and the other two rows are cool. The end result is a fairly pleasing look without having to gel.

URL: Comer CM-LBPS1800 On-Camera LED Light (Sony Battery) | L.A. Color Pros

The light has a screw for a tripod mount. If one needed three for a kit, maybe they would make a deal to be more competitive with the ones you're looking at.

One other thing to add: it is really bright! Oh, and another, I've never used the flip-down gel filter but in a test it does suck up the light.

If there is one light like this then there are probably others doing something similar. I just haven't been looking.

Re: 1x1 LED Gels?
 

Bi color or 2 color led panels are made up of 50% daylight and 50% warm ( tungsten warm) leds. The warm led tints are lower in light output by approximately 20-30% less than the daylight ones. In general the cool daylight ones are always brighter than the warmer counterparts due to the thinner phosphor yellow layer on top of the led die as opposed to the thicker yellow layer used on the warmer leds. It is like the led has already applied the Color Correction for you when they added that thicker layer on top. If you take only the blue daylight leds by themselves and apply a gel to "warm" it down to indoor( 3200K) then the light loss 20-30% would be almost the same as the warm leds themselves. On the panel types that use many leds for example 1000 leds, 500 that are cool and 500 that are warm, when the cool ones are on the light output of the cool ones are 100% but when the warm ones are also turned on at the same time the cool ones are reduced in brightness so that the warm ones can be mixed with them. If all the cool and all the warm are forced to be at 100% bright then the thermal characteristic of the enclosure may require extra active cooling as not to cause overheating. Contrary to beliefs that leds run cool, they do run mighty hot indeed, especially at high brightness levels. You may notice also that when BOTH sets of leds (cool + warm) are at full brightness, the brightness is not double of the individual set. That is because the sets are connected in parallel configuration equally sharing the input current to them thus reducing the current draw and hence the apparent brightness is reduced to about 50% per set. A variable color dial just distributes that 50-50 to 90-10 or 80-20 or 70-30 etc. It makes no sense to put a light robbing correction gell if the bi-color leds are available unless the price difference is big.

Re: 1x1 LED Gels?
 

I won't argue with Arthur's explanation but what I can tell you is the 1000 LED colour variable panels at my local rental house (Chinese "knock-offs") do dim significantly when pushed all the way either cool or warm. The panel is brightest blended 50/50. By how large a margin, I have no idea.

Using Lee Filters as a guide, Transmission Factors are below for CTO and CTB:

LEE Technical Lighting Filters - Daylight, Tungsten and Fluorescent Conversion

FULL
CTO 55.4% CTB 34%

HALF
CTO 70.8% CTB 54.9%

QUARTER
CTO 79.1% CTB 69.3%

Using CTO filters on a daylight instrument is more efficient than using CTB on a tungsten instrument.

Yes, gels rob you of output but being smart about usage makes the light-theft manageable.

My 2 cents...

Re: 1x1 LED Gels?
 

It stands to reason that the effect Shaun describes would happen because both sets of LED's are fully up when the color temp knob is at a halfway position, but only one set is up when it is at either end. A "smart" unit would either modulate the level of the LED's to maintain continuous output regardless of color temp, or allow for a "boosted" mode such as this one provides for maximum output.

Re: 1x1 LED Gels?
 

For a truly constant output of the light's brightness when either cool or warm or "mixed" would require additional electronics other than the PWM type dimming scheme. It would also take in consideration of the led's "binning specs" into factoring that non-linear performance characteristics of the different cool or warm led types, also the fact that dimming varies output differently in both led types and what is OK and equal to the math end is often perceived as not just equal to the human eye, even if the meter readings of lumens/lux may be equal, the human eye would see the different color temperatures output more or less, with everything else being equal.

Re: 1x1 LED Gels?
 

At least part of that is incorporated into products such as the Litegear Hybrid dimmer (LED LiteDimmer HYBRID LITEGEAR). My definition of constant output would stop at what a meter would read, I don't expect it to take into consideration how any given camera or the human eye would read it, as that is too many variables.

Re: 1x1 LED Gels?
 

A liitle on the pricey side though. The dimmer I use for my projects is a 7A non PWM type that is flicker free and has a variable dimming potentiometer ( log type or audio taper) and a fine trim adjustment so that both the cool and the warm leds show as equal brightness as perceived. I use two in tandem so that one driver controls the cool and the other controls the warm with a common single dimmer for overall brightness. The two color pots are connected individually to each driver but are "ganged together" and using one control knob for color adjustment. In reality both drivers can output 14A continuous if needed and measure 1.5 inches across. The nice part is that they accept a wide DC input voltage of 7 to 24 V DC. I made a 16,000 lumen led studio light using them. The light outputs 1000W filament equivalent, battery operation via 14.4 volt DC feed.The light draws only 155 watts. Not bad for a portable light when generators or AC plugs are not allowed or available.

Re: 1x1 LED Gels?
 

To my eyes, I don't perceive any difference at all in luminence when my Litepanels 1x1 bi-color flood is changed from 100% tungsten to 100% daylight. But according to my lightmeter, there is about a 20 fc difference at 4 feet. The tungsten setting reads 140 fc and the daylight reads 120 fc.

However with that said, if I was buying lights today, with what I know now, I would not get bi-color lights. I cannot even remember the last time I used any of my lights on the tungsten end of the spectrum. It's been 100% daylight balanced for me for at least a couple of years.

Re: 1x1 LED Gels?
 

...and conversely, I rarely turn my hybrids towards daylight. Nearly all the times I'm working in a 5600 environment, the light level is too high for small units like 1x1's to have much impact.

I'm building super-light enclosures for the Literibbon which allow the LED's to be swapped out from tungsten to daylight to hybrid as easily as sliding gel in and out (plus plugging in); also allow for diffusion panels and grids to be quickly added . Should be very useful.

Re: 1x1 LED Gels?
 

For the record, my experience was with the Chinese knockoffs and it was certainly more than a 20% difference...

Re: 1x1 LED Gels?
 

90% of the lighting I do is for interviews or other headshots at locations outside of a controllable studio. And a lot of those locations have windows. Going with daylight balanced fixtures allows me the option of using whatever natural daylight there already is in the room to my advantage - rather than fighting against it. I find that my interviews look much more natural these days compared to the days when I was using tungsten lighting and pretty much all the daylight sources had to be snuffed out one way or another. And even if there is no natural daylight present, I can still light the interview with daylight-balanced fixtures in a dark room just as easily as I could with tungsten-balanced fixtures. For the type of things I shoot, daylight fixtures give me a lot more freedom.