Radiance FAQ

FAQ Contents

General setup questions
Questions on input settings
Questions on output settings
RS232 control questions

General Setup Questions

Q: Will I see an improvement in picture quality with the Radiance as compared to the Vision series of video processors?
A: The Radiance series does improve on the already excellent picture quality delivered by the Vision Series video processor. Here is a comparison of the video processing features of the two Lumagen video processing families:

Vision Series
· Proprietary Lumagen “no-ring” scaling
· Spatial noise reduction for SD/HD sources
· Mosquito noise reduction for SD/HD sources
· Per-pixel SD/HD video deinterlacing
· 8-bit input resolution to an 8-bit frame-buffer. All (except VisionDVI) use a 10-bit video pipeline for processing (note that SD deinterlacing is 8-bit).

Radiance Series
· Proprietary Lumagen “no-ring” scaling with improved precision
· Temporal and spatial noise reduction for SD/HD sources
· Enhanced Mosquito noise reduction for SD/HD sources
· Adaptive diagonal filtering
· Enhanced per-pixel SD/HD video deinterlacing
· 10-bit input resolution plus 10-bit video pipeline.

Where the improvement is most noticeable is with poor-quality sources, such as cable and satellite feeds. Cable and satellite companies over-compress the video material to provide a large number of channels on a limited bandwidth signal. The enhanced processing in the Radiance series provides additional circuitry to improve these poor quality sources as compared to the Vision series.
tially set all controls to their defaults on the display and the Lumagen. The Lumagen controls are used for all calibration adjustments except as follows. Calibrate the DVD player first. Set the black (.brightness.) and white (.contrast.) levels for the DVD source using the brightness and contrast controls on the display. Then, for other input memories and other inputs, use the Lumagen BLACK and CONTRAST controls to adjust for differences between inputs and also between light and dark room conditions. If a video technician is calibrating the grayscale (.color-of-gray.), they should use the display color-temperature adjustments, when available, for 100 IRE and 30 IRE. Then the Lumagen service mode 5-point color-temperature controls can be used to fine tune the grayscale.

In some cases the display geometry adjustments may be needed to position the image, and it is often necessary for the display to be set to the correct mode for proper display. For example, when driving the display from the Lumagen using DVI/HDMI it is very important that the display be in set to .pixel-perfect. mode and that any .frame-rate-control. be defeated when ever possible. Pixel-perfect mode for the display defeats its internal scaling so the Lumagen can be used to best advantage. Frame rate control is used in some plasma displays to change the vertical frame rate. This rate change causes motion judder for video sources and should be turned off if possible. If it is not possible to defeat frame rate control, set the Lumagen to output vertical rate to match the native frame rate of the monitor.

Q: What controls do I use on the display and which on the Lumagen?
A: Initially set all controls to their defaults on the display and the Lumagen. The Lumagen controls are used for all calibration adjustments except as follows. Calibrate the DVD player first. Set the black (.brightness.) and white (.contrast.) levels for the DVD source using the brightness and contrast controls on the display. Then, for other input memories and other inputs, use the Lumagen BLACK and CONTRAST controls to adjust for differences between inputs and also between light and dark room conditions. If a video technician is calibrating the grayscale (.color-of-gray.), they should use the display color-temperature adjustments, when available, for 100 IRE and 30 IRE. Then the Lumagen service mode 5-point color-temperature controls can be used to fine tune the grayscale.

Q: I made changes, but when I next used the Lumagen, the changes were missing.
A: Changes must be saved (using the SAVE->SAVE command) or they will be discarded when the Lumagen goes to standby mode.

Q: So what is .black crush. and .white crush.?
A: If the levels are set incorrectly, or adjusted incorrectly, it is possible that the output does not change in level even thought the source level changes. This can be seen in the AVIA PLUGE pattern or a stair-step test pattern. IN the AVIA pattern the 2 and 4 IRE bars, or the 96 or 98 IRE bars may not be visible. In a stair step this would show as some the steps being wider than they should be because two or more input levels are output at the same level. This can dramatically reduce fine detail in either dark or bright scenes.

Q: I set black and white levels in my darkened room. Why does it look so dark with the lights on?
A: The calibration needs to be done at with the ambient light levels intended for viewing. So, if video is to be viewed both with the room darkened and with the room lighted, the calibration must be done in both environments. Black and white levels are most affected, and just recalibrating them for the lights on condition will provide good results. However, color, and color-of-gray, are affected by the room environment. So, for the best image quality the calibration should be repeated for these critical parameters. To accomplish the second calibration, first complete the dark room calibration, then copy the memory that configuration memory to the configuration memory to be used for the bright room calibration (IN->COPY->ALL). This will speed up the recalibration process.

Q: What output resolution should I set my satellite receive to?
A: If available, the output of the satellite receiver should be set to .hybrid. mode. Inthis mode a satellite receiver will set its output resolution to its input.s resolution. That is SD for SD material, 720p for 720p material and 1080i for 1080i material. Unfortunately most satellite receiver manufactures fail to support this most basic feature. Others have supported it in the past but now choose to ignore this critical feature. Some satellite receivers allow the user to manually select different output resolutions. When possible with these receivers, select the receivers output resolution that matches the source resolution.

Note that setting the satellite output to always be 1080i forces SD deinterlacing and scaling to occur in the satellite receiver. This bypasses the Lumagen deinterlacing and scaling, limiting its ability to improve the image. However, calibration features, such as color, hue, Y/C-delay, etc, are still available.

Questions on input settings

Q: How should I set the input level on my Lumagen?
A:As with analog sources, the Lumagen input level setting should match the output level of your video source. DVI and HDMI sources use the same levels, which can be either .PC. or .Video.. PC levels use the entire range for black to white. Video levels allow for blacker-than-black and whiter-than-white. To assure the ability to calibrate the input levels, and prevent black or white crushing of the levels, it is critical that the correct setting is used. Make sure the Lumagen input level (IN->CONFIG->ADJ->LEVEL) matches the source. Note that some sources report their output levels incorrectly, so it may be necessary to try both settings. Also note that PC levels prevent the blacker-than-black portion of some PLUGE patterns (such as on the Video Essential DVD) to be visible.

Q: I set the input and output levels on my Lumagen, but the test patterns still show black or white crush?
A: Even after the input and output levels are properly set, there may be some black or white crush in the image. This is due to differences in the products from various manufactures, and also due to normal variations in analog video hardware. Start with the display brightness and contrast in their default position. Use the AVIA .Needle Pulse. PLUGE pattern to adjust the display.s brightness and contrast so that the 2, 4, 96 and 98 IRE moving bars are correctly visible. Then use the AVIA .black field with 2 and 4 IRE bars. pattern to adjust the black level properly for dark scenes. The black level setting is almost always different for bright and dark scenes. Lumagen recommends that the dark 2/4 IRE pattern be used since black is most critical in dark scenes. Of course it is still critical in bright scenes, but if it is adjusted using the Needle Pulse test pattern, dark scenes may become too black. After adjusting balck and contrast per the instruction on the AVIA disk, use a quality movie transfer to check and perhaps make adjustment to the black and white levels. If the scene looks like is has a .haze., the black level it probably set too high. If the image looks overly dark, than black level may be set to low. White level is generally less demanding and so is less likely to need adjust using real video material.

Q: I set the Lumagen to pass-through mode. Why does the input video still get scaled?
A: The pass-through is only active when the input resolution matches the output resolution. For example, if your input source is 720p and you set the Lumagen output mode to 720p, pass-through can then be active. If the input source changes to 480p the pass-through is automatically disabled.

Q: I see dotted green lines randomly appearing on my projector, is there something wrong with my Lumagen video processor?
A: This is most likely caused by mismatched output timings between the Lumagen and the expected input timings of the display. Adjust the Lumagen output timing to best match the display.

Another possibility is a poor quality (or too long) HDMI or DVI cable. Just try a shorter one to check for this.

Questions on output settings

Q: How do I select the output resolution for the Lumagen?
A: For DLP and other digital displays connected to the Lumagen by DVI/HDMI, set the Lumagen output resolution to the native resolution of the display. For example, for DLP based displays this is often 1280x720.

The exact resolution and timing for analog outputs varies. Rear-screen CRT based displays are often 1080i, but front projectors can generally accept a number of resolutions. For CRT projectors, some suggested starting points, based on tube size, are 720p for 7 inch, 840p for 8 inch, and 960p for 9 inch.

Q: How should I set the output level on my Lumagen?
A: Setting the Lumagen output levels is parallel to setting the Lumagen Input levels. The Lumagen output level should be set to match the displays input level requirement. If the display can accept VIDEO levels, Lumagen recommends that this be selected. This will allow blacker-than-black and whiter-than-white, which can help in optimal calibration. Set the output level using the OUT->MISC->LEVEL command.

Q: I set the input and output levels on my Lumagen, but the test patterns still show black or white crush?
A: Even after the input and output levels are properly set, there may be some black or white crush in the image. This is due to differences in the products from various manufactures, and also due to normal variations in analog video hardware. Start with the display brightness and contrast in their default position. Use the AVIA .Needle Pulse. PLUGE pattern to adjust the displays brightness and contrast so that the 2, 4, 96 and 98 IRE moving bars are correctly visible. Then use the AVIA .black field with 2 and 4 IRE bars. pattern to adjust the black level properly for dark scenes. The black level setting is almost always different for bright and dark scenes. Lumagen recommends that the dark 2/4 IRE pattern be used since black is most critical in dark scenes. Of course it is still critical in bright scenes, but if it is adjusted using the Needle Pulse test pattern, dark scenes may become too black. After adjusting black and contrast per the instruction on the AVIA disk, use a quality movie transfer to check and perhaps make adjustment to the black and white levels. If the scene looks like is has a .haze., the black level it probably set too high. If the image looks overly dark, than black level may be set to low. White level is generally less demanding and so is less likely to need adjust using real video material.

RS232 control questions