Flagship Home Theater - Part 1: Anthem LTX-500 LCoS Projector and SI Black Diamond II Screen


The Anthem LTX500 LCoS Projector On the Bench

The LTX-500 is both a simple and an extremely complex display.  On one hand, you can engage the THX mode and simply enjoy the projector as-is.  As you’ll see in the below charts, it’s quite accurate.  In fact the LTX measured better out-of-the-box than any other display I’ve measured before.

If you want the ultimate in accuracy however, you must calibrate the projector.  Every aspect of display performance can be adjusted.  It is extremely rare that any display has as complete a set of controls as the LTX-500.  The data I collected shows that a thorough calibration is well worth the effort.

A few weeks into the review I received a firmware update for the LTX-500.  This update can be downloaded from Anthem’s website and installed via laptop through the projector’s USB port.  It’s a simple process that took all of about ten minutes.  The update makes some very positive changes to the color management system.  As you will see below, the color measurements before and after the update are quite different.

Equipment used:  EyeOne Pro spectrophotometer, CalMAN Professional 3.3 analysis software, Accupel HDG-3000 signal generator, Spears & Munsil Benchmark Blu-ray.

All measurements were taken off the screen (Carada Brilliant White, gain 1.4) from the seating position (10 feet back) with the iris set to -6 out of 15 steps.

Grayscale and Gamma

The THX mode measured very well.  Tracking for both gamma and grayscale was well within standards.  The average gamma of 2.03 was mainly affected by the higher stimulus points.  The gamma at lower levels was closer to 2.2.  This means shadow detail was well-rendered.  The color error from 20 to 70 percent was below the range of visibility.  The slight tendency toward blue was not a problem when viewing content.

Anthem LTX-500 LCoS Projector and SI Black Diamond II Screen

After calibration in the User mode, grayscale and gamma tracked to near-perfection.  The firmware update did not affect my ability to adjust either parameter.  Since the update erased all settings from the previous calibration, I started from scratch

Anthem LTX-500 LCoS Projector and SI Black Diamond II Screen

The only minor difference can be seen in the RGB Level Tracking chart.  After the update, I was able to get things a bit flatter at 20 percent.  We’re talking nits here!

Anthem LTX-500 LCoS Projector and SI Black Diamond II Screen


Without calibration, the only accurate color mode is THX.  The color accuracy is quite good with a near-perfect gamut and decent luminances.  The projector is very watchable in this mode and few people would have issues with image quality.  In the THX mode all adjustments are locked out for grayscale, gamma and color management.  You can change brightness, contrast, color and tint.  You can also select the standard, enhanced or auto modes for black level setup and colorspace.  (Figure 11)

Anthem LTX-500 LCoS Projector and SI Black Diamond II Screen

With firmware 1.0, this was the best color gamut I could achieve in the user mode.  I’ve included the Ideal Secondaries chart to show that despite the inaccurate primaries, the LTX properly calculates the secondaries.  The Luminance chart shows what I was able to do with the color management system.  This is a very good chart.  (Figure 12)

Anthem LTX-500 LCoS Projector and SI Black Diamond II Screen

These are the results of the CMS adjustment with firmware 1.1.  There was no need to use the Ideal Secondaries chart because as you can see, it is possible to achieve a perfect CIE Gamut.  Luminances are superb as well.  Only a tiny number of displays, of any type, can achieve this level of accuracy.  (Figure 13)

Anthem LTX-500 LCoS Projector and SI Black Diamond II Screen

Color accuracy can be a very subjective thing.  On one hand, the projector was immensely enjoyable with the oversaturated gamut.  I would consider it to be the finest in its class and finer than many projectors costing more without the firmware upgrade.  With the ability to achieve perfection though, this display is in a whole different league.  As I watched movies with the 1.0 firmware I couldn’t help but wonder what the image would look like if the color were perfect.  It’s a personal thing with me: knowing how a display measures affects my perception.  I’ve measured and calibrated a lot of TVs and projectors and I always prefer accuracy, but that’s me.  Your mileage may vary.

Contrast Performance

The LTX-500 achieved the highest contrast ratio I have ever measured from a front-projection display.  Arriving at these numbers was difficult, mainly due to the limitations of my color meter.  The EyeOne Pro has a lower practical limit of .001fL (that’s really dark).  When I measured a 0 percent pattern I often got no reading whatsoever.  I took 20 measurements and got .001fL on 12 of them.  Rather than measuring the maximum light output, I set the iris to give me around 12fL at 100 percent stimulus.  So in my theater for practical purposes, I achieved a contrast ratio of 12,000 to 1.  The projector is obviously capable of greater output as I had set the iris at -6 out of 15 steps.  So I might have achieved a higher CR measurement but the image would have been too bright to be watchable.  When using the Black Diamond II screen, I was unable to get a single measurement for 0 percent.  I adjusted the iris to give me the same 12fL peak.  The contrast ratio with the Black Diamond II was therefore higher than 12,000 to 1.  To my eye, the Black Diamond II did give the image a little more punch and saturation.  I found it very pleasing to watch.  In fact it reminded me of a certain plasma TV that will be unavailable soon!

Video Processing

Obviously the best source material for this and any 1080p display is Blu-ray disc.  Keeping the content at its native resolution from the beginning to the end of the signal path means there is no processing required.  That being said, most of us have large DVD collections and will likely continue to watch SD content for some time to come.  For this reason, the LTX-500 uses the Silicon Optix Reon solution.  When fed 480i content from my Denon 2930CI DVD player, the LTX did an excellent job with all aspects of scaling, de-interlacing and cadence detection.  You could pair this display with a simple flag-reading player and enjoy excellent image quality.

For 24p content from Blu-ray disc, the LTX-500 refreshes at 96Hz.  There is no option for frame interpolation.  The cadence is simply 4:4.  Though some like the smoother motion inherent in frame interpolation, I find it odd-looking and unnatural.  I did not miss this feature.

Performance of the Black Diamond II Screen

The Black Diamond II is built for two things:  high contrast and ambient light rejection.  It performed extremely well in both areas.  Contrast (both perceived and measured) was definitely greater than my Carada screen, even at the same gain of 1.4.  I noticed a slight color shift towards blue which was verified by measurements.  Gamma also required some tweaking.  If you use this screen, you should calibrate the projector by measuring off the screen for best results.

When I first set up the 1.4 gain Black Diamond, I noticed a very slight sparkle effect at the center.  I could only see it when there was a uniform image like blue sky or a road for instance.  In all fairness, my wife could not see it even when I told her what to look for.  I did ask SI Screens about this issue and they told me it is known and they are working on it.  The .8 gain material did not exhibit this tendency.  Overall though, I preferred the extra pop from the 1.4 gain screen.  It certainly did not reduce my enjoyment of watching movies!

To test ambient light rejection I used a torche-style lamp which I moved around the room to see its effect on the image.  Even with the lamp directly across from the screen at full brightness, I could easily see medium to bright images with almost no reduction in quality.  Darker scenes took on a slight color cast from the lamp but detail was still nicely preserved.  When I placed the lamp on the sides of the screen, there was almost no effect on the image.  If your room has indirect lighting that does not throw light on the screen, you can have an extremely watchable picture without creating black hole conditions.  Of course to enjoy the full contrast potential of the Black Diamond II, you’ll need to turn off all the lights as I did.