The sun is well recognized as the perfect light source because of it’s completely uniform, continuous and broad spectrum. With the development of artificial lighting technologies, efficiency is improved significantly, however, the illumination quality gets worse. There is no longer a light source that is like incandescent or halogen with perfect spectrum, especially when LED was invented and widely applied. While achieving unprecedented energy saving benefit, we have sacrificed the illumination quality tremendously until the Yujileds VTC series LEDs come out.
The wavelength range for human visual sensitivity is generally considered as 400nm – 700nm, for which the sun spectrum covers completely. On account of the illumination principle, a standard LED only covers 430nm – 670nm with at least 20% relative radiant power compared to the 450nm peak wavelength, therefore the purple and deep red light are misssing in a standard LED. Furthermore, the sharp peak of the blue light has been an intractable challenge for many years.
Yujileds VTC technology succeeds in broadening the spectrum coverage to 400nm – 730nm, which is 40% more coverage than a standard LED spectrum. In addition, the VTC technology eliminates the sharp blue peaks then achieves the homogeneous spectral power distribution hence it achieves 95% similarity to the sunlight within the visible spectral range.
Not limited to a fixed full spectrum, the VTC technology offers at least six spectral patterns of 2700K, 3200K, 4000K, 5000K, 5600K and 6500K as standards and can extend to even wider CCT scopes. The spectral recipe of each CCT is well designed with Yujileds state-of-the-art LED phosphor and the well-chosen LED dies. By covering the practical solar spectra at any time all day, the illumination quality will never be compromised regardless of any CCT is selected. Eventually we can obtain a better light source than incandescent and halogen based on LED with the full flexibility of different white lights thanks to the VTC technology.
CRI (Color Rendering Index) is a most accepted colorimetric for evaluating the ability of a light source rendering the original color of an object. Benefiting from the full spectrum, the VTC series LED performs remarkable color rendition by achieving the CRI up to 98 (with minimum 95) where the full-score is 100. Comparatively, a standard 80 CRI LED which is still widely used performs less color fidelity and saturation.
The TM-30 metric is defined and proposed by the Illuminating Engineering Society (IES), aiming to provide comprehensive evaluation on color quality of new light sources especially for LED and it is released as the supplement or even replacement of CRI in the future. TM-30 utilizes 99 color evaluation samples which are selected from more than 100,000 measured objects to be representative of the world of possible colors. Compared to CRI, TM-30 is more critical on the spectral quality therefore when a standard LED has a CRI as 97, the Rf (Fidelity Index) of TM-30 is about 90, but for VTC series 99 CRI LED, the Rf is maintained at 95-97 which means the VTC technology provides extremely stable ability for rendering most of the possible colors.
Colors are not only well rendered under one specific spectrum but for all CCTs covering from the warm white to daylight. As the result of the well-designed spectral recipes, CRI values are ensured to be constant and since the VTC technology focuses on the spectral quality, likewise the TM-30 scores are maintained at high values constantly.
The importance of LED color consistency is as crucial as the color rendition. For the new generation of VTC series LED, the SimpleBinning technology is introduced. A standard LED usually comes with more than ten different chromaticity bins for each CCT which is always complex and confusing customers. With the SimpleBinning technology from Yujileds, there will be no more than two bins for each CCT and the individual bin equals to or less than 3-step SDCM, that is to say, not only the selection of chromaticity bins is greatly simplified, but the consistency of each bin is ensured. Particularly, the performance of consistency will be even more superb when applied on a Yujileds PCB with our chromaticity management.
The VTC technology is based on a unique illuminating principle than the standard LED by applying a typical 405nm LED die (violet) that excites blue, green and red phosphors. Despite only changing the die and adding one phosphor seemingly, the illumination theory makes the technical procedure different. In Yujileds VTC technology, the triple phosphors are completely tailor-made for matching with the violet die for the full-spectrum performance, which makes the spectral recipes extremely complex. Nevertheless we still have achieved stable color rendition and SimpleBinning. The VTC technology represents the most advanced LED technology at present.
Surface Mount Device
|Package size||2.8mm * 3.5mm||2.8mm * 3.5mm|
|Forward voltage||3.0V – 3.4V (0.1V interval binning)||3.0V – 3.4V (0.1V interval binning)|
|Luminous flux||10lm – 18lm||20lm – 32lm|
|CRI / R9||97 / 90||97 / 90|
|Rf / Rg||97 / 101||97 / 101|
|Spectral power distribution (normalized CSV)||2700K||3200K||5000K||5600K||6500K|
|Quick sample dispatch|
Chip On Board
|Package size||13.5mm * 13.5mm||13.5mm * 13.5mm|
|Forward voltage||14V – 17V||14V – 17V|
|Luminous flux||390lm – 510lm||800lm – 1100lm|
|CRI / R9||97 / 90||97 / 90|
|Rf / Rg||97 / 101||97 / 101|
|Spectral power distribution (normalized CSV)||3200K||5600K|
|Quick sample dispatch|
Delta optical thin film focuses on complex optical filter technology for more than 50 years and it is one of the first companies to produce ultra-hard-coated optical filters. Today, the design and manufacture of high-performance fluorescence filters are the main business, and with the in-house design and production tools, Delta continues to meet the needs of the discerning OEM customers.
During the evaluation of Yujileds VTC series LED, Delta Linear Variable Bandpass Filters (LVVISBP) is applied for the measurement. The measurement procedure is as simple as putting the filters in front of the light sources, but the phenomenon is noticeable by naked eyes directly, especially when comparing to a fluorescent lamp and standard LED. The spectrum theory sometimes is difficult to understand but this measurement perfectly explains the relationship between spectral and visual differences. Every detail in the spectrum could be presented in the result after the filters, and eventually the importance and value of a full-spectrum LED should be widely accepted.
OUT e.V. processes the detailed and impartial measurements on Yujileds VTC series LED for a comprehensive performance of different working temperatures and electrical currents. Apparently, the photoelectronic parameters perform stably which makes the VTC series LED adaptive for wide applications.
Indie Cinema Academy is a professional organization focusing on providing the education of film school level concepts and techniques to bring the audience’s video projects up to the level of the masters. Indie Cinema Academy makes the skills accessible and explains every step of the way the hows and whys of the camera and lighting choices.
Lighting plays the decisive role in film shooting and Indie Cinema Academy has done a great job of collecting all LED databases from the market to compare the color rendition quality and rank the different brands or products. CRI and TM-30 are both evaluated considering the rationality and impartiality to the professional level. Yujileds VTC series LED gets the runner-up with CRI Ra 98.4, CRI Re 97.5, TLCI 99.5, CQS 97, Rf 97 and Rg 100, only defeated by the sun.
I have never seen color captured by my digital cameras so accurately. This makes my heart sing. Really.
I want to fill the photons of my sensor; It is not enough with a strip of Led light. With two Led strips it is better for Color Management in my favorite photo editing software. I have assembled two Led lighting panels. I bought a strip of Led lighting in May 2017, it has rendered me with an Illuminance of 1600Lux at approx. 80cm until now. Recently, I bought a new one, adding an illuminance of 3200Luxs, placing the lens 80cm away from the bottom and the position of the lighting panels. In addition, the panels were placed at 45% to avoid the lack of uniformity and thus have a better performance.
These are the only 2700K LEDs I've ever seen which feel truly natural and not just some ugly artificial yellow color. I've built a ceiling light for my living room using 10x 2700K and 10x5600K MCPCB modules. I really like variable color temperature. About 10.000 lumens might seem a bit overkill for a living room light, but it's actually just right. During the day, if I set the color temperature of the LEDs to match the light coming from the windows, everything blends perfectly and the boundary between "indoors" and "outdoors" seems to disappear. It's like the natural light from the outside is reaching all the way inside. This feels very natural and pleasing, it would only work with full spectrum LEDs like the VTC. which are visually identical to daylight At night I set color temperature lower, using only the 2700K plus a bit of 2200K BC strip, and it feels very warm and cozy. Anyway. I'm very happy with this purchase.
Tested with my Sekonic C700 color meter and it’s true, these are extremely high quality white LEDs!
I got VTC 135L COB for 5600K for a very specific reason - they are the only single LEDs on the market to cover 400-700nm range. I am using them as full band light source for spectral responsivity measurements (see https://github.com/Alexey-Danilchenko/Spectron project). Before them I used Xenon pulsed light source but LEDs are far more controllable. I have several suggestions to improve it though. 1) UV range starting with non zero intensity at 380nm would be simply brilliant for the colour related spectral applications 2) More powerful COBs are really needed - for my needs I ended up using 4xVTC 135 XL COBs and somewhat convoluted construction. It would help a lot having single COB with larger intensity 3) advisory on COB mounting and 3rd party or recommended holders/mounts/etc.
With LR2 Spectrometer (LaserTack) i got : T = 4600 ° K (u, v) = (0.21, 0.33) (x, y) = (0.36, 0.37) R1, R2 = 99 R3 = 96 R4 to R9 = 98 R10 = 96 R11 = 98 R12 = 83 R13 = 98 R14 = 97 ===================== To resume : CRI average = 98, T = 4600°K Spectrum conforming to specs Very good rendering, pcb not too warm with thick aluminium base I use it to light paintings and drawing work. Recommended product.
I can only praise this LEDs for their quality. They use violet LED and 3 (or more?) different phosphorus for best Sun spectrum distribution imitation possible. (5000K, 5600K) The warm white (2700K) is good for spectrum mixing with daylight (5000K, 5600K) in the evening or at night. I am slowly starting to transition all my lighting in house to these LEDs as they have such natural look. The product I am making will be able to mix in warm white with a rotary knob 🙂 The 2 problems I have are: high price (which can be totally excused because of the spectrum quality) and time/development of the mixing circuits. Now to explain my enthusiasm. I was long having issues with my aquarium: - When using T8, T5 lighting the spectrum degraded within a year so I would need to buy new lamps every year => high pollution + expenses. When the spectrum degraded the plant growth slowed, stopped and algae boom happened. And even when the lights were new I was able to grow very limited number of plants. - When I transitioned to ordinary LEDs (only white phosphorus, very unnatural spectrum distribution), I was having algae problems non stop and no plant growth. - During the test different fertilization methods and aquarium maintenance styles were used, so the test would need a repetition to say for sure! After this I tried to find a different lighting source and I discovered violet based white LED. Yuji company was the only company which sold them to consumers. So I bought 5000K and 5600K VTC 2835 chips, mounted them on custom PCB, made an alu holder and put them on aquarium. The results from images are obvious: no algae growth under these LEDs! Under these lights the plants only need fertilization to grow otherwise they start to grow slowly and slowly die back. For fertilization I use organic fertilizer for garden plants that does dissolve slowly. IMAGES: > 100 New plants bought for testing, STANDARD WHITE LEDS (white phosphorus) https://www.flickr.com/photos/94092356@N08/37726147472 300 Results: plants grow but algae are favored because of STANDARD WHITE LED spectrum, at this point I have changed to YUJI VTC 5000K and 5600K LEDs https://www.flickr.com/photos/94092356@N08/37048779464/in/photostream/ 400 Results: no algae growth on plants! Lower brightness but plant growth still present https://www.flickr.com/photos/94092356@N08/37499552630/in/photostream/ 500 Results: excellent 🙂 (the plants were just thinned because of so much growth) https://www.flickr.com/photos/94092356@N08/37757964041/in/photostream/ Plans: - buy some very difficult to grow aquarium plants and test how they grow in this simple system - change lights to STANDARD WHITE LEDs to check for sure if they are the cause for algae booms.
I checked these Chips to find a one chip solution with a spectrum close to D50 and I was amazed about the quality.
The difference has to be seen to be appreciated; colors jump out in spectacular fashion. Color details in artwork are more clearly delineated than with any of the other light sources with which we’ve experimented. As good or better than the best professional lamps. Museum quality.
I'm using YUJI's VTC LED strips for terrarium lighting (dendrobates). So far the plants are growing extremely well. Great color rendering!
Worked better than advertised, fast shipment
The VTC series by color ribbon easily has the best color rendering quality of any similar product I have tested. Many other companies overstate their CRI numbers. I think that YUJI is accurately marketing a high-quality product with a very high CRI.
Yuji LED's are superb, sturdy, compact, low heat, very luminous, video does not need post color treatment, best investment on my video production rig.
Took pictures with the camera set at 5600K and the color is beautiful.
Got both BC and VTC versions. Ended clearly preferring the VTC version which looks and feels absolutely right. The only disadvantage is that the off-centre positioning and placement pitch of the LEDs is not compatible with any readily available linear lenses (e.g. from LEDIL). Might need to have a custom MPCB made before I can use them for serious projects.
Really great spectrum from these UV-based LEDs. I had a hard time finding these. Finally I found Yuji. I will shurely be back for more.
The light from these high CRI LED bulbs is wonderful for illuminating works of art, woodwork, food and people; whatever you want to see as it really is.
Quality beyond CRI. All colors appear as they should. This new light source allows me to continue my watercolor painting at night with no misperception of color. Great product!
The 5600K VTC bulbs seem very well built, and the color reproduction is amazing. It really does resemble true sunlight.
I am using this LED strip as a replacement of standard Warm White Incandescent light bulbs. I almost see no difference in the color rendering when compared to incandescent light. Excellent popping colors, especially Reds. Stands up to the claims of CRI and R9 thru R15 values.
Colour quality is incredibly high, nver used another LED than can compare. 100% worth the extra cost over typical LEDs.
These lights are cheaper than the film lighting competitor here in the states, and have a higher CRI, thank you. These lights render beautiful images for my studio.
I'm a professional color printer who makes Dye Transfer prints. I was looking for a very color accurate LED light source which gives as good a result as Tungsten Halogen. I have tried other LED light sources but all were too inaccurate for color judgment of a fine print. With the Violet / RGB phosphor LED light I am able to get an exact match to my profiled monitor. Until now, I would say LEDs were not capable of critical color matching, but this experience has changed my mind. These LEDs should be used in all museums and art galleries to replace the existing stock of Tungsten Halogen fixtures.
The high CRI products are amazing. Excellent brightness and amazing color. Most people instantly think it is too blue but that’s when the view the light from afar. When they actually stand within the light, it is quite natural, indeed reminiscent of daylight. Service was very quick. An order placed on Friday evening arrived at our doorstep in Las Vegas on the following Monday morning. Not quite sure how that feat was accomplished but it was happily received.
This lamp gives better colour rendition than anything else I have tried. High cri at 6000 Kelvins picks out even deep blues.
Very nice light. Almost ideal spectral curve. Little invisible peak at 405nm, slight dip at green 565nm (but maybe it's better for face looks good). Steeply falling after 640nm, so deep red color probably less than I would like to see. I test two types of Yuji LED samples by spectrophotometer, and both of them have a good light spectrum. On the Yuji website is the same spectrum graphics and they can be trusted. Course I would like that there was no peak at 405 nm, but it still a better and wider range than ordinary LEDs. And Violet can be filtered out by additional UV filter or covering.
I personally quest for a excellent color LED for years. Finally that ideal LED exists an Violet chip with CRI better than 95. My main usage is Video and Film production lighting. Which required fabulous quality of light. Yuji LED makes it happen. There is no gel or filtration of color to make it look right on Video or Film camera bang! right on Color temperature and Tint balance. Endorse for kind of person who wish to have LED that look excellent on set.
This high-CRI COB LED is just awesome!! Being a tint snob, finding an LED with CRI over 96 and the special RIs all being over 90, especially R9, is exactly what I've been looking for!!! Particularly amazing, it's available in 5600K as well!! Thank you!
Even the blue chip has fantastic color reproduction. Best I have found yet. (using for custom video lights.)
The light looks really natural, much more than standard high CRI LED, and it makes a very pleasant atmosphere. it's an excelent alternative to halogen bulb at home.
My spectr.measurement is confirmed high CRI. Compared to the declared spectrum I registered a slight decline of the blue phosphor (blue band). Overall satisfaction.
Tested, works great. quality product. truth full spectre light! works great from 24v pwer supply with 18 Om 5W resister!