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Watch Reflecmedia and Chromatte related video clips in the Advanced Chromokey section of our website, contact our head office team or your local reseller for assistance (Contact Us), or visit our Resources page for handy downloads and user-guides.
Chromatte
Chromatte is a fabric designed specifically for use as a background for chroma key production. Unlike conventional Chromakey fabrics that are usually blue or green in color, Chromatte is grey to the eye in ambient light. The fabric contains millions of tiny glass beads that act as reflectors, returning any light shone on them back to its source.
When the directional light form Reflecmedia’s lens-mounted LiteRing (Reflec Media LiteRings are available in Dual Color or Single Color formats) hits the Chromatte fabric, it is returned on the same path and back into the camera’s lens – as such the camera sees the otherwise grey fabric as a perfectly even blue or green background. Due to the number of glass beads within the fabric, the camera and LiteRing are free to move and can work at acute angles to the fabric. In the extreme you can screw the fabric in a ball and still key against it!
Chromatte Drapes
Chromatte is supplied in a range of standard size or custom produced studio drapes, the fabric is backed with a black light-proof drape and hemmed with eyelets across the top for easy hanging from studio tacking or rail.
Standard Studio Drape Sizes:
Deskshoot Lite (Does not include backing)
8′ (W) x 8′ (H)
Wide Shot
12′ (W) x 7′ (H)
Small Studio
13′ (W) x 10′ (H)
Wide Studio
16′ (W) x 10′ (H)
Studio
16′ (W) x 13′ (H)
Cleaning Chromatte
Maintaining the quality of Chromatte through cleaning and careful storage will extend the life of its reflectivity levels. Here are some simple guidelines to follow:
Dust and moisture will deteriorate the reflectivity within Chromatte if left to settle.
LiteRing
Reflecmedia’s Chromatte fabric is designed to work in conjunction with a LiteRing (Reflec Media LiteRings are available in Dual Color or Single Color formats). The LiteRing features Light Emitting Diodes (LEDs) arranged in a circular casing that is positioned in front of the camera lens. This provides all the light required to illuminate the Chromatte background for Chromakey production.
The LiteRing connects to the camera with a specially designed adapter ring, similar to those used for matte box mounting, which is attached to the inner thread of the lens. The LiteRing is then placed on to the adapter and simply locked with two grub screws. This enables users to quickly release the LiteRing in between shots. The Dual LiteRing can switch instantly from between green and blue colours.
We have taken the blue or green color away from the fabric and completely removed the need to separately light the background. The ability to change the background color in seconds cannot be achieved any quicker – no need to hang a different drape or repaint the studio walls! Tungsten, HMI and Fluorescent lights can be large in size, expensive to power and uncomfortable to work under. Typically you require thousands of watts to light absorbent Chromakey fabrics, whereas the LiteRing’s 10 watts output provides all the light required by Chromatte.
By relocating the color and the light into one camera-mounted device, we have significantly reduced the set-up time and overcome many of the difficulties associated with conventional chroma key.
Reflecmedia LiteRings are available in Dual or Single Color options and in sizes to fit different cameras. Each size of ring has a series of adapters to ensure maximum compatibility with camera lens sizes. Further custom adapters and fixing mechanisms are available.
Small
72mm with adapters for 72|62|58|52|43|37|30 lenses
Medium
112mm with adapters for 105|95|94|86|82|80|77|72|67 lenses
Large
147mm with an adapter to fit 127 lenses
LiteRing Controller
The LiteRing controller enables you to regulate the amount of light emitted from the LiteRing. The amount of light is registered by an illuminated display on the front of the Controller. A 4-pin XLR connector allows you to connect power via the Reflecmedia Power Supply or from a camera’s battery. This gives you flexibility when in a studio or while in the field. For Dual LiteRings, the Controller allows you to change keying colour from Green to Blue in the flick of a switch.
Power Supply
To enable the LiteRing to function, we supply one of the following 12v power supplies depending on your geographical location, US, UK, Asia, or EU.
Our head office is based in the UK and our team of specialists are available to assist you.
Reflecmedia have an international newtrork of Distributors and Resellers.
Please click the following link for assistance in placing an order.
Check out the Advanced Chromakey section and Resourses sections of our webiste for more information as useful downloads such as the Reflecmedia User Guide.
Our head office team and international network of Distributors and Resellers are also available to assist you: Contact Reflecmedia
Due to differing import tarrifs, taxes and distribution costs around the world, Contact Relecmedia or our Internation Network of Distributors and Resellers for local pricing information.
Please contact our Head Office Management Team for more information and assistance.
Check out the Matte box rail adapter and the Push on adapter kit for wide broadcast lenses, the Push on adapter kit ships with a clasp adapter which clamps onto the outer edge of the lens barrel.
The Matte Box Rails Adapter: Designed for cameramen who use matte box rails, Reflecmedia offers an attachment solution for its medium and large LiteRings. The medium adapter provides a solution to mount the medium LiteRing to both 15mm and 19mm matte box rails; the large adapter attaches the large Litering to 19mm rails only. The lightweight black anodised aluminium adapter provides the operator with a quick and accurate alignment of the LiteRing and lens.
Link to: The Matte Box Rails Adapter product datasheet
Link to: Reflecmedia LiteRing Adapters Product Information
The Push-On Adapter Kit: Specifically designed for lenses without a filter thread, the kit consists of an anodised aluminium adapter machined to provide the attachment for a medium LiteRing and a custom machined insert specifically designed to couple the adapter to the lens barrel.
The inserts can quickly be interchanged to accommodate lenses with different barrel diameters. The push-on adapter kit is supplied with one adapter for the lens barrel diameter specified. Other adapters are available to special order.
Adobe After Effects with Keylight tutorial. Also, Apple Motion tutorial, PHYX, Ultimatte Advantage, Primatte, dvMatte, Keylight from The Foundry is also available for Avid, FCP, Combustion etc.
Ultimatte is the best on the expensive side. For an inexpensive pre-viz solution, also see Veescope with the Mac, or the Blackmagic Design ATEM family.
Absolutely. We have tested with the TCXD300 and it works very well. Simply use the eyedropper to select the color and begin to adjust the parameters to clean up the key.
Camera and Lighting Setup for a Chromatte Shoot
Before you start to light ensure the camera is set up as follows:
Iris : Manual
Gain: 0db
ATW: Off
White balance: Preset or Manual White Balance
Setting the Camera’s White Balance
If for any reason you alter the white balance, go through the above process again ensuring the light you use does not have any colored gels on and that all other lights are switched off.
Setting Up the Lights
The lighting levels depend very much on the sensitivity of video camera you are using, however as a general rule you should be trying to light to between 500 and 1000 lux. This is typical of a 650w fresnel lamp flooded at approximately 15 feet from the subject. The use of a steep back light behind the subject illuminating the head and shoulders is also recommended. This light can be placed anywhere behind and above the subject but is normally placed on the same side as the key light to add both direction and separation to the key.
You should not attempt to illuminate the Chromatte, however any ambient spill onto the Chromatte will not be a problem at all. Do not place a key light directly above or on axis to the camera as the light from this lamp could dilute the effect of the Chromatte by creating a hot spot.
The distance from camera to subject will depend on the framing of the shot and the type of lens on the camera. Typically a distance of about 9-15 feet would be normal. At greater distances you will have to increase the LiteRing power or open the camera iris to compensate for the distances involved. The use of two backlights is optional, however this does allow more control.
As far as subject to background distances are concerned, you do not need to leave large amounts of separation between subject and background as you would with traditional blue or green screen as there is no spill from the Chromatte curtain. Should you wish, you can place your subject flat up against the Chromatte curtain, however you may wish to leave a small gap (approx. 3 feet) to accommodate the back lights as suggested above.
If your camera has a built in LCD display or your have a monitor, you can increase the LiteRing power until the blue or green starts to washout (you will see this as a slight color hue change on the monitor). Backing off the LiteRing until there is no color shift will give you a maximum setting.
If you are recording the foreground to tape for compositing in post, it is worth while initially testing the system to ascertain the best settings for the LiteRing. A short timed recording of your subject at several fixed LiteRing settings will provide a test for your optimum setting. Digitize this clip and note the setting that provides the best key.
Introduction to Keying: Keying is a technique by which separate foreground and background images are combined together to create a single composite image, eg the TV weather. This is achieved by recording the foreground against an evenly lit coloured background. This background is usually blue or green, however in theory any colour could be used.
Blue was initially chosen as the key colour as it does not appear at significant levels in flesh tones. Green is used as an alternative for darker flesh tone and for when the foreground contains significant amounts of blue. Green also has a higher luminance value than blue and thus requires less light to produce a satisfactory output. Chroma keying, Bluescreen, Greenscreen and Colour Separation Overlay are all terms used to describe this process.
Traditionally the blue background is a stretched self coloured curtain or painted studio walls and floors. Large quantities of lighting are required to light the curtain evenly (typically 1Kw per linear yard). This light must be placed several feet in front of the curtain to provide an even spread. The actors therefore have to be placed even further forward of the curtain to avoid interaction with the curtain lighting and to avoid spill from the reflected light hitting the actors. Considerable skill and time is required to achieve a well-lit background, and the amount of background light used precludes the use of subtle foreground lighting. The setup also generates a great deal of heat and consumes large amounts of electricity.
Using Chromatte there is no need to light the background at all. All illumination of the backing is achieved using a ring of light emitting diodes (LEDs) attached to the lens of the camera. The LiteRing only consumes 10 watts of power, yet still produces an even illumination of the cloth wherever the camera is framed. Creases and folds will not affect the quality of the key due to the random arrangement of the glass beads on the surface of the cloth. Actors can be placed close to the backing and there is negligible spill generated by the screen. Your foreground lighting can thus be as subtle as you like. When using our Dual LiteRings, changing the background colour is instantly achieved by switching the LEDs from Blue to Green, or vice-versa..
The process of combining the foreground with the background can be achieved in two distinct ways.
Live Keying: Normally found within the TV studio environment, a hardware keyer is an electronic device that combines the foreground cameras output with that of the background image. It may be a standalone unit or may be integrated within the vision mixer or switcher used by the studio. In either case the controls will be similar however, manufacturers will describe these controls in slightly different terms. A standalone keyer tends to have more operational controls than one that is integrated into a vision mixer, although modern trends in software based control has allowed switchers to emulate standalone keyers in complexity. Keying is achieved in real time and the composite image is then broadcasted or recorded to tape.
Typical hardware keyers and mixers: Ultimatte, Crystal Vision, Darim, FOR-A.
Keying in Post Production: In this instance the foreground image is shot against the blue or green screen and recorded to tape. The clip is then digitized via a computer and the keying process is achieved using software keyers. These programs are almost always part of a larger more complex software package. The package may be a Non Linear Editor such as Final Cut Pro or Premier Pro, or a dedicated compositor such as Adobe After Effects, Eyeon’s Digital Fusion or Shake.
The keyer component could be an integral part of the original program or it may be provided by third party manufacturers. Most controls within software keyers work in a similar way to their hardware counterparts but may be referred to in slightly different terms. A quick look in the user guide should enable you to identify the controls. To produce the final composite image the software usually renders the sequence from by frame, in some cases this action may be done in real time.
List of software keyer plugins and compositors: Ultimatte Advant Edge, Adobe After Effects, Eyeon Digital Fusion, The Foundry Key Light.
Download this white paper from Reflecmedia titled “Halo and Shadow explained“.
From: https://www.reflecmedia.com/files/downloads/15/1/HaloShadow.pdf
Halo and Shadow: The function of a retroflective camera system is to cast a key coloured light (usually green or blue) originating from the lens, in the direction of a subject being filmed in front of a retroflective screen. The emitted light covers the camera’s entire field of view and thus where the camera “sees” the screen, the coloured key light is reflected directly back down the lens to the image sensor.
You may notice that when using a Chromatte drape or a Chromaflex that there may be darkness around or to the sides of the subject. This darkness, depending on the cause can be identified as halo or shadow or more usually a combination of both. Halo and shadow are both optical effects caused by the physics of the lens interacting with the retro reflective media and are the results of the source of light (specifically, the blue or green litering) being in a different location along the optical path, to the reflected light converging on the film or CCD plane of the camera.
If the iris of the lens was stopped down to create a single point of convergence for the incoming light and the light that was emitted to illuminate the retro reflective screen emanated from this same single point, there would then be no halo or shadow when using retro reflective systems.
By deviating or expanding laterally from this position (in the case of an iris), we create halo.
By deviating linearly from this position, we create shadow.
Halo: A function of the light source not being a single point in the center of the lens (rather spread out around the lens). This effect is exaggerated due to the iris not being a single point in the center of the lens but rather a variable sized circle of acceptance for the incoming light. Halo is distinctly different from shadow in that it gets brighter as you move away from the edge of the subject and since it is created by the optical imaging system, you can only evaluate it relative to your camera by looking through your camera, not by looking off-axis at the screen with your eyes.
Shadow: A function of the light source (even if it is a single point in the centre of the lens) being in front of or behind the point where light imaged by the camera appears to converge. Maintaining this relationship is made more difficult, by the fact that when you zoom a lens, this convergence point will move closer or farther away, while the retroflective light source remains stationary. Shadow is literally cast by the subject blocking the light that is otherwise illuminating the retro-reflective target. If the source (the litering) is behind the destination (ccd or film plane) then the camera will represent a narrower angle than the illuminator relative to the subject so the shadow of the subject will appear smaller than the subject. Likewise, if the source is in front of the destination, the camera will represent a Halo and Shadow greater angle than the illuminator relative to the subject and the shadow will thus be greater than the subject.
As there are some obvious laws of physics working against this optimal setup, we attempt to get the best possible results by having the light source and destination both mechanically and optically as close to each other as possible.
The closer the subject comes to the camera the more the effects of halo and shadow are exaggerated, so in many cases, a similar shot framing can be achieved with less halo and shadow by backing off the camera away from the subject and zooming the lens in (or using a tighter prime lens).
In both cases of shadow ( whether larger or smaller than the subject) it will probably be visible, and even if the shadow is the same size as the subject, if the light source and lens destination are not single points, there will also be halo.
Optimized camera set-up for required exposure range: Halo is a function of the retroflective light source not being in the center of the lens, and the iris being opened wider exaggerates it. In situations where you can not reduce halo to an acceptable level, it is often effective to close down the iris to reduce its effect. Consequently, there will be a reduction in exposure. More light can be added to bring the exposure back to the previous level, without adding to the halo effect.
Optimized camera set-up for required zoom range: Considering the fact that the destination point of the lens changes when you zoom, you cannot hope to have perfect linear placement of the litering across all zoom ranges. This sometimes results in one end of the zoom range having a greater shadow by product than the other.
In this case, assuming that the mechanical design will allow, it may be possible to shift the litering to a more optimal location along the lens axis causing the shadow to be reduced to a minimum where you need it most, at your most critical zoom range.
It is important to note that in most situations where halo and shadow appear, it is not because the scene can be shot in a way that allows one to completely avoid halo and shadow, but rather because the layout of the shot (including the retroflective screen, litering, subject and camera) has not been setup with the goal of minimising the effects of halo and shadow.
If the person responsible for creating the key is aware of the above issues, an optimal image may be achieved.
With the ever-changing camcorder environment, and a wide variety of lens choices for today’s DSLR users, we wanted to make sure that Reflecmedia users arrived on set with everything they needed to get to work.
All Medium Sized Reflecmedia bundles now include one free adapter of your choice. Potential sizes are:
67mm, 72mm, 77mm, 80mm, 82mm, 86mm, 94mm 95mm, 105mm LiteRing adapters
All Small Sized Reflecmedia bundles now include one free adapter of your choice. Potential sizes are:
30mm, 37mm, 43mm, 52mm, 58mm, 62mm, 72mm LiteRing adapters
In a low light environment the LiteRing provides all the light required to achieve the background color. A blue or green LiteRing may, as your only light source, cast its light on the subject, which may not be desirable. This can usually be rectified using a key or fill light on your subject/object, or by simply reducing the output level of the LiteRing. Chromatte will not work as well in very bright shooting environments where the level of other light sources overpower and neutralize the effect of the LiteRing. The retro-reflective action between the LiteRing and the micro glass beads is needed to achieve desired keying results.
Yes – but subject to the ratio of ambient lighting to the intensity of the LiteRing being sufficient to generate a key (be aware that in outdoor use lighting is continually changing). The material is made using 100% natural cotton and is not suitable for using in wet conditions (this is also not covered in the license and warranty). You may find it beneficial to view the return of the blue or green light from the LiteRing through a monitor or color viewfinder on the camera. Chromatte is designed principally for use in controlled lighting environments.
Not during regular use. If it were left outside for lengthy periods (which is not recommended) then it may fade over time.
When hung in a dedicated studio space it will last for years. If walked on it is subject to usual wear and tear and possible tearing. Dust will affect Chromatte’s ability to key properly, reducing the reflectivity of the beads hence absorbing more of the LiteRing source than is ideal.
Ideal handling advice is to hang it and not fold it, although you can use a cool non-steam iron on the revers if required. (NB: A benefit of Chromatte is that it can handle creases). If it is to be stored then it should be rolled up and kept in a dust free container. Store above 41 degrees farenheit and below 77 degrees farenheit, in a cool and dry environment. Use a soft ‘clothing’ brush to remove any dust marks.
The combination of the LiteRing and the retro-reflectivity of the fabric means that the camera can move from 90 degrees head on, to up to 30 degrees from horizontal.
Where the fabric is purchased on its own we recommend it is hung in vertical panels running in the same direction rather than running several meters horizontally or in different directions. A supplementary piece of fabric can be used to join two pieces of Chromatte, this will mask any gap between your two original pieces.
If you make every effort to close the tear and not leave a hole then, yes. A tear or hole can be patched without any significant reduction in quality.
Chromatte is fire retardant and the fabric meets all necessary approvals. An FR certificate can be provided with more information.
Chromatte is designed to return the source light on the same axis as it enters the fabric i.e. it can be used at multiple angles. While it can be used to project an image on to (for instance as a guide when working with virtual sets) it is not designed as a projection screen.
Chromatte is platform independent and will work as a chroma key background for use within any software or hardware keying solution.
You white balance with the LiteRing off. White balancing with the LiteRing on will not give a true representation of the blue or green emitted from the LiteRing.
Depends on both usage and the level of intensity, but realistically several years. LEDs have an extremely long life span and never need replacing.
There are currently 3 sizes available, to suit DV, Broadcast and HD camera lens sizes. The LiteRing connects to the camera by way of an Adapter, these are available in different sizes for different lenses.
With a subject in-between it can work at a minimum of 10 feet and up to 45 feet away.
A lot of new cameras have a detail setting built in, which electronically sharpens the image. This can also be called Core Processing, Contour Setting or Aperture Correction. Most camera presets have the detail setting set at high. Lowering the detail setting can improve the key resolution.
The cameras contour processing that electronically sharpens the image takes its reference from the green channel of the camera. This graininess will not affect your key, however you could reduce the camera’s detail settings slightly if you wish the green to appear less grainy.
This could be because there is too much ambient light directed at the curtain. Large quantities of ambient light will affect your key especially if this light is on axis to the camera. Move the lights off axis and ensuring they do not fall on the curtain will improve saturation. It could also be because you lens aperture or LiteRing controller settings are not optimized.
The shadow or halo you see is a product of the retro-reflective process that Chromatte utilizes. You can reduce this effect in several ways. Place the subject closer to the curtain, move the camera further back, zoom in to reframe, iris the camera down and relight or readjust the LiteRing controller.