3 minute read
The Aputure Accent B7c is a film bulb designed to fit into standard household light fittings making it ideal for colour accurate practicals.
Aputure recently released the Accent B7c, a mains power and battery operated 7W RGBWW colour-mixing LED light bulb. It’s the first product in the new Accent family of LED lights built for filmmakers. The B7c features a standard E26/27 fixture but unlike typical household LED bulbs, the lamp uses cinema grade LEDs to reproduce skin tones with CRI and TLCI values of 95+ and a tungsten SSI score of 85.
Aputure claims the B7c bulb can produce over 90% of the saturated colours in the Rec.2020 colour space, which puts the bulb on par with industry-standard lighting instruments.
Unique for a bulb that fits ordinary lamp shades, the B7c features 20KHz step-less dimming that remains completely flicker-free up to at least 1,000fps with no colour shift. With a frame rate of 240fps, there was not a flicker to be seen while the colour indeed remained the same throughout.
Aputure Accent B7c.
The Accent B7c not being an ordinary light bulb is apparent from its ability to match the colour temperature range of the Nova P300c, Aputure’s most advanced colour mixing light, producing a wide colour temperature range of 2,000K-10,000K.
Aputure Accent B7c colour accuracy
However, the accuracy of the Kelvin values in the app for the light bulb is not something to brag about. I took measurements with an Illuminati M-100, M-150 and a Lumu Power Pro Gen.2, all three light/colour sensors that I connect to an iPad Air 2 and that have been developed specifically for LED lighting.
When measuring at 100% output @ 40 cm distance, all three meters agreed within a 40K margin that the output was off — 180K at the lowest app setting and a whopping 2500K at the highest. However, when combined with the Sidus app’s SourceMatch feature, the app and light bulb combination does match nearly any white light source pretty accurately.
Source: LED lamp 12W at 100% measured as 2590K.
Match value: B7c at 100% measured as 2720K with a -1/10 magenta shift.
That’s pretty close and for a lamp like the B7c the latter is more important than the former. For the colour temperatures themselves you will probably use a light meter to set the temperature on the app’s continuous scale from its low to its high, anyway.
Aputure Accent B7c.
The B7c is the first bulb designed for filmmakers that has a built-in battery, powering the B7c for over 70 minutes at full power, and over 20 hours as it approaches minimum brightness. In AC power mode, the B7c retains its last settings and turns on and off like a traditional light bulb, allowing for natural interactions with actors. In DC operation, the lamp is meant to be used more like an off-camera light source.
To operate the bulb off the grid, you need to first turn it on with the tiny On/Off switch on its side. What I did notice and isn’t stated anywhere in the Quick Start guide or on the website as far as I know, was that you need to hold the power switch down a while before the B7c will turn on. Turning off happens instantly after pressing that button.
With only the switches to work with, e.g. when you don’t have access to the app, the brightness and CCT can be increased/decreased using the two outer buttons.
The B7c doesn’t look like an ordinary light bulb in that it uses an aluminium structure and a toroidal diffusion design, with the diffusor the smallest part of the lamp. Yet, it spreads light as evenly as ordinary light bulbs for use inside lamp shades.
Aputure Accent B7c.
Finally, when you use the Sidus Link app, the Accent B7c has access to its built-in lighting FX mode as well as SidusPro FX. Furthermore, using your iOS device’s camera, the Sidus app will let you pick any colour (not just from other lamps) and will set the lamp to the closest colour it can output.
That feature worked very well and you can even customise the intensity, hue and saturation afterwards. Another FX capability lets you cycle the lamp in all kinds of configurations between two white colour temperatures and intensities.
Yet another one that I found fascinating is the Picker FX effect where you record a number of colours, e.g. from a colour patch deck like Pantone’s, and let the B7C play the colours back as you recorded them with the iOS device camera.
The Accent B7c retails at €74 but soon they will be available in a configuration of eight lamps inside a robust carry case with built-in charging power.
Tags: Production
Comments