|Camelot Technology Crystal Vision VPS-1 Video Processor|
|Home Theater Video Processors & Switchers Video Processors|
|Written by Kim Wilson|
|Thursday, 01 January 1998|
Camelot Technology's Crystal Vision VPS-1 is an adaptive 2-D digital comb filter with four levels of edge enhancement which also functions as a video switcher. In most cases, the VPS-1 will serve as a superior comb filter compared to those now incorporated in Laserdisc players, VCR's and TV's.
A comb filter is designed to separate a composite video signal's Chrominance (color information) and Luminance (brightness or black and white information). These two signals, often referred to as Y/C, are transmitted via an S-Video connector. Errors in Y/C separation cause visual side-effects such as cross-color or cross-luminance commonly referred to as dot crawl (or hanging dots). This color separation process impacts the total potential of the video portion of your home theater. When you insert the VPS-1 between your Laserdisc player and your TV, their internal comb filters are bypassed in favor of the VPS-1.
As the composite video signal enters the VPS-1, it is digitized with an A-to-D converter. To achieve a sharper and more detailed picture, the color separation process must adapt its characteristics based upon the content of the scene. The VPS-1's adaptive, digital logic circuit continuously evaluates the video image and selects the most effective processing between its three filters. Additionally, the VPS-1 uses digital edge enhancement to sharpen an image's edge transitions.
After the VPS-1 performs its color separation and edge enhancement, a D-to-A converter converts the separated digital video signal back to analog, producing a 10-bit, S-Video (Y/C) output.
The VPS-1 uses an external power supply (which normally I dislike because it takes up at least two outlets on your power strip) however, this supply is designed differently. With a dedicated power cord the supply itself can lie flat on the floor.
The VPS-1 provides four inputs (two composite and two S-Video) and one S-Video output, however if your TV monitor is old enough that it doesn't include a S-Video input, you will be unable to use the VPS-1. The composite inputs allow for both comb filtering and edge enhancement while the two S-Video inputs simply pass through the signal. In order for me to take advantage of the VPS-1's circuitry, I connected the composite output of my Pioneer CLD-79 Laserdisc player and Toshiba VCR to the two composite inputs on the VPS-1 video processor.
DVD and DSS sources derive their S-Video signal from component video and do not require a comb filter. Offering S-Video pass-through inputs for DVD and DSS sources allows the VPS-1 to serve as a complete video switcher in place of your preamp/receiver. In the default mode, the VPS-1 automatically switches to the first, active video source it detects. If all your video sources are active, then you need to select the proper input manually.
I was stunned by the remarkable improvement in picture quality afforded by this small little box. The comparison between the Pioneer's composite output with and without any processing was astonishingly dramatic.
At the top of side three of the Men in Black (Columbia, Dolby Digital) Laserdisc, I was immediately struck by the striking detail and sharpness I found in the facial features. Flesh tones were rendered perfectly, revealing almost a radiant quality and the edges were razor sharp and well defined. Without processing, everything went flat and edges were extremely soft. The improved separation process created more black in the picture for richer and purer colors. The entire picture was far more vibrant with extended depth of field.
The comparison between the Pioneer's internal comb filter and the VPS-1's was less sensational, but it was still apparent that the VPS-1 incorporated the better processor. Color detail and sharpness were very close, though facial features were slightly softer on the Pioneer. The main advantage was how the picture just 'popped' with the VPS-1 in the signal path, an indication of an improved grayscale, which translates into greater depth of field.
Comparing the output of a VPS-1 processed Laserdisc alongside a DVD source was also revealing. I used Apollo 13 (MCA/Universal, DTS), since I have it on both DVD and Laserdisc. Skin tones and color accuracy was still purer on DVD despite the improvements to the Laserdisc. DVD had more detail in general not just in the edges. Screen lettering was impressively similar between the two, but exhibited less fringing around the edges. It was close in some aspects, but DVD proved itself superior.
My personal viewing habits don't generally include VHS tapes, but as a major fan of the X-Files, I do have the commercially dubbed videotape collection. Popping one in the deck I discovered noticeably more detail, increased edge enhancement, and a more accentuated depth of field. Even though bright colors exhibited far less blooming, videotape is still videotape and there is only so much you can do with the medium.
In using the VPS-1's edge enhancement feature you have to be careful not to over sharpen the image, otherwise the picture rings making it look noisy. I recommend using it sparingly. I found either no edge enhancement or level one to be sufficient.
The dimensions of the VPS-1 are much smaller than your average A/V component. This 7" x 7.5" stylishly designed silver-faced box may look out of place if you have all black gear stored neatly in a rack or cabinet. Fortunately, it can be hidden after installation, as it works automatically once all the preferences are set. While video switching is automatic, the four input LED's blink sequentially until the VPS-1 detects a signal. If the unit is out of sight, this is of no consequence, but if it is in plain view, it's a bit distracting.
Obviously these minor points don't effect or detract from the VPS-1's exceptional performance. For those individuals concerned as much about appearance as performance this information may bare more weight, however it would be nice if the VPS-1 was also available in black.
If you have a large Laserdisc library, you'll truly appreciate the remarkable improvement provided by the VPS-1. Due to the advent of DVD, Laserdisc technology has reached its peak and the VPS-1's $549.00 price tag is a small price to pay to significantly upgrade your present video system.
Now, if you spend most of your time viewing VHS tapes and don't even own a Laserdisc player, the cost may be too steep. While, I could see improvements in VHS playback with the VPS-1, it just wasn't as dramatic. Moreover, without 5.1 audio to accompany it, the improved picture just seemed less important. For that kind of money, you'd be better served buying a DVD player.
The accuracy of the video portion of your home theater is equally as important as your sound system for maximum enjoyment. If you, like most people, are using a rear screen projector or a direct view TV, the VPS-1 is the best and only option for dramatically improving the picture quality of Laserdisc and VHS tapes.