good rgb or input levels—that is, the drives and blacklevels for each of the three colors, red, green and blue—ensure that images from analog sources other than decoded video have maximum contrast without crushing black or white. by default (and in an “auto setup”), the projector automatically determines the best input levels by monitoring image content and adjusting the controls appropriately—further adjustment is typically not required to obtain proper blacks or whites. note: this automatic adjustment requires at least 2 consecutive white pixels in the image.
without these pixels, input levels may produce skewed colors, particularly in nonvideo images.
however, for a very unusual source exhibiting one or more overly high blacklevels (typically caused by a noisy source causing blacklevel spikes), an experienced user may prefer to use the input levels menu (shown above). these adjustments, which together serve as a calibration process compensating for differences in sources and cabling, enable an experienced user to perfect the source image input levels and eliminate the “overshoot” and “undershoot”. note that input levels are of limited use with digital signals, but do offer some ability to tweak poorly mastered source materials.
auto input level–keep off for virtually all sources (default). temporarily enter a checkmark only if you are an experienced user and you have an unusual source that you feel needs further color temperature and/or input level adjustment. after entering a checkmark, wait for the six slidebar values to stabilize, then delete the checkmark and exit. this compensates for incoming out-of-range drives (white) and blacklevels (black) that would cause “crushing” of light and dark colors in the image.
blacklevels and drives - to check your image and adjust these controls:
1. make sure overall “contrast” and “brightness” settings are both set to near 50. note: not required for “auto” adjustment.
contrast=50(approx.)
bright=50(approx.)
2. check the color temperature setup using an internal grayscale test pattern, making sure to obtain a neutral grayscale. note: not required for “auto” adjustment.
3. confirm that you are using an analog source not connected to input 3 input 4, as input levels are not applicable for digital sources or sources going through the decoder. a grayscale is recommended.
4. if the blacks and/or whites appear ok, input levels do not need adjustment. if black levels are too high (and/or whites are too low, which is rare), you likely have a noisy source that is producing skewed input levels. continue with step 5.
5. temporarily enable “auto” in the input levels submenu. wait for all 6 values to stabilize. alternatively, do not use “auto”—reduce blacklevels manually instead. judge by eye and change one or more of the six levels as necessary to obtain proper blacks and whites. you may want to see only a certain color while adjusting—use the “color enable” option (described below).
6. delete the “auto” checkmark and leave the input levels menu.
do not use input levels to adjust color temperature. this will distort contrast and brightness functions as well as color temperature.
auto color enable–when a checkmark is present, selecting a specific blacklevel or drive to adjust will automatically enable the corresponding color in the display. delete the checkmark to see all colors.
clamp location–this option (formerly known as sync tip clamping) can brighten the image produced from certain highresolution high-frequency graphic sources. for almost all sources, the best clamp location is automatically selected by the projector.
use the normal back porch location if the image is either sufficiently bright or overly bright. select sync tip if the image appears unusually dim, if there are horizontal streaks across the image, or if there is significant color drift. this moves the clamping pulse from the normal backporch location (which is likely too short) to the tip of the horizontal sync pulse. tri level is typically recommended for an hdtv source where the back porch is also short.
clamp location is not used for video sources or any rgb source with sync information included on the video (e.g., sync-on-green). use tri level instead.
color enable–select which color or colors you want to see in the display, useful while working with color temperature white levels or input levels.
1) input levels apply for the current source only, but for any color temperature used. 2) assuming that color temperature has been set up based on the internal test patterns, you can then set up input levels for a given source so that it matches the color temperature of the internal test patterns.
peak detector–the peak detector is a fast method for defining individual input levels, and can improve the accuracy of input levels set by the auto input level function. enabling the peak detector activates a special operating mode for detecting only pixels that are considered black or white—all other levels are displayed as a mid-level gray. when used with a smooth grayscale pattern in which black and white are known to be at opposite edges of the image, you can watch these isolated areas while adjusting individual blacklevels and input drives until both black and white edges are just visible and distinguished from neighboring pixels. images from this source will then display correct blacks and whites without crushing.
see figure 3.13. adjusting input levels using the peak detector:
1. display a 16 level grayscale test pattern from the desired external source, and enter a checkmark in the peak detector checkbox. note: the “peak detector” will initially render the grayscale as a uniform gray field before adjustment.
2. display one primary color (use color enable to select).
3. for the current color, adjust its corresponding “blacklevel” slidebar just until a single band of black appears at one edge of the screen. this band represents the first band of the grayscale pattern, which should be 100% black. do not adjust too far.
4. with the same color still active, adjust its corresponding “input drive” slidebar just until a single band of color appears at the opposite edge of the screen. this band represents the last band of the grayscale pattern, which should be 100% white (or the current color, if a certain color is enabled). do not adjust too far.
5. go back and check the black band—adjust the blacklevel slidebar if necessary. adjustments are related, so you may have to go back and forth until both bands are just optimized.
6. repeat steps 2-5 with the other two remaining primary colors. when each primary color shows one optimized black band and white (or colored) band, the input levels for this source are correctly set. upon exiting the input levels menu, the peak detector checkbox will clear.
advanced image settings—submenu
gamma table: this control selects and applies the normal 2.2 gamma setting or a user-defined “arbitrary” (custom) gamma table that has been previously downloaded to projector memory (these custom gamma tables—a.k.a. curves—are typically created in christie’s arbitrary gamma application for the pc, and are downloaded via a separate utility). use of custom curves can improve performance for certain kinds of source input and applications. generally the best gamma curve is one that produces maximum contrast, brightness and color performance for the current signal and ambient lighting conditions.
if no such curves have been defined and downloaded to projector memory, only the “2.2, normal” default gamma curve is available here—adjust as desired in the main image settings menu.
select color adjustment: in “select color adjustment”, choose an overall color palette for all images.
the “max drives” factory default simply drives all 3 colors at their maximum level so that they are fully on and cannot be changed. the two other pre-defined color adjustment choices—sd video and hd video—apply a color gamut optimized for video sources (standard or high-definition). alternatively, you can specify a color temperature. this enables the adjacent color temperature slidebar and applies its current setting (default = 6500k). if none of the pre-defined “select color adjustment” options or color temperatures suit your application, select one of four color gamuts previously defined by a user (user 1, 2, 3, 4). a “user” option applies a customized color performance in which the user has precisely set the hue and intensity of each color component in the color adjustment by x/y or color saturation submenus. it is most often needed with multiple-projector applications.
select the color adjustment producing the best color accuracy for your application and installation.
to configure a “user” color adjustment (gamut), use either the color adjustment by x/y or color saturation submenu.
1) “color temperature” defaults to 6500k until changed. all four “user” options default to sd video unless they have been redefined by the user. 2) factorydefined color primaries, which ensure consistent color gamut from projector-toprojector, can be altered in the service menu only. if you suspect alteration, the factory settings can be recovered with selection of reset to factory defaults? in the service menu (password-protected).
color temperature—adjust to apply a specific and accurate color temperature to all displays. color temperatures are expressed in degrees kelvin (3200-9300k), and utilize different combinations of the projector’s original native color primaries to produce a “coloration” or cast (reddish or bluish) in images—the lower the temperature, the more reddish the cast; the higher the temperature, the more bluish the cast. note that the slidebar is enabled only if you have a source connected and have selected “color temperature” in the adjacent “select color adjustment” pulldown list in the advanced image settings menu.
frame delay—set the interval of delay desired between the input signal and its appearance on screen. for applications such as simulation, where the feeling of “real time” image response is a priority, a minimum setting is usually preferable. for projectors capable of 3d (stereographic) applications where alternating left-right frames must be synchronized with the corresponding l/r shutters in 3d glasses, a frame delay setting of two (or multiple of two) may be more useful. delay may vary between sources.
dark interval—when displaying stereographic 3d images, adjust dark interval to artificially increase the amount of dark time between displayed frames. higher settings provide more time for shutters in 3d glasses to open/close, ensuring that each eye sees the full display intended for it. symptoms of cross-talk and/or color artifacts can indicate need for adjustment. the dark interval range of adjustment depends on the vertical frequency of your source—the higher the frequency, the smaller the range.
see 3.10, 3d images for a full explanation of dark interval use.
3d stereo sync—this option defines 1) whether or not the incoming stereographic 3d signal locks to the vertical sync output so that signals are synchronized, and 2) whether or not the 3d frames must be inverted, i.e. swapped left-with-right. the correct setting ensures that the projector’s 3d display of left/right frames is synchronized with the rest of the 3d system components so that left/right image data is seen by the intended eye. select the option corresponding to your 3d source connections and timing, and use only if the mirage 3d stereo sync cable is connected between the projector’s gpio port and a server (this cable replaces the need for a separate ttl inverter as described in 3.10, 3d images). keep this adjustment off (default) when you are not using the mirage 3d stereo sync cable.
with your sync cable, z-screen and, if desired, emitter connected as described in 3.10, 3d images, select the option suited to your 3d configuration (see above). if frame delay is 2 (or 0), do not invert; if frame delay is 1 or 3, invert. generally, an “unlocked” setting is synchronized with the incoming l/r signal rather than the vertical sync output, and may be needed only with multi-projector installations in which the vertical sync outputs vary.
see 3.10, 3d images for a full explanation of 3d stereo sync use.
3d stereo sync select—define which of the mirage 3d stereo sync cable’s input connecters is routed to your server. input a = bnc connector, input b = 3-pin mini-din connector. use only if the cable is present. note: regardless of which input is connected, the output routes to both outputs.
see 3.10, 3d images for a full explanation of 3d stereo sync select use.
3d stereo sync delay — set when the l/r frames begin, defining the best reference point for synchronizing the display with your glasses. proper adjustment of this delay should eliminate cross-talk and odd colors caused by timing differences between the glasses and the projected display. use this slidebar only if the mirage 3d stereo sync cable is connected between the projector’s gpio port and a server. slidebar values indicate the number of lines that are delayed.
see 3.10, 3d images for a full explanation of 3d stereo sync delay use.
motion filter—this control is most useful for smoothing out moving images from interlaced sources. in most cases the proper motion filter setting is automatically determined according to the type of incoming source signal. however, if your source is jittery and/or tearing you may wish to “force” a setting to ensure stable processing for this source—if desired, override the default “auto” setting by selecting the appropriate motion filter:
1. auto: the projector will automatically use the correct motion filter according to the incoming signal.
2. still: for static images with no motion, such as graphics from a cd.
3. motion: for video images that did not originate from film, or for moving computer-generated images.
4. film: for video images that originated from film. this will optimize image quality and stability.
film mode threshold—this setting determines how sensitively the projector can detect if an incoming video signal originated from film or not.
detail threshold—use “detail threshold” to define at what frequency level the “detail” control will begin to magnify high frequencies, which adds details back into the image. raise the threshold to ignore more of these high frequencies, and lower the threshold to magnify more of these frequencies. a setting of “0”, for example, means no noise will be ignored and all will be magnified. an ideal detail threshold is one in which high frequencies that are causing objectionable noise are not magnified when using “detail”, but frequencies which can help sharpen an overly-soft image are magnified when using “detail”.