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Preface:

These are initial impressions and experimentation with the P752. I am working on the P752 related issues that I discuss. My configuration is temporary and not preferable except as a learning environment and for ease of access. My comments refer specifically to my VT540 but may be applicable to any other projector that vents to the front. Sorry, no pictures are available.


Configuration:

I have a VT540 and P752 combination. My sources are a Unity Motion HDR-1000A, 4DTV/HDD200, and an HTPC (700MHz Athlon, 256MB, 16x DVD, Viper II, Vortex 2, yadda). The UM and HDD200 utilize component video so as to enable the vertical stretch capability of the VT540 (SD and HD). The HTPC signal is RGB with aspect ratio control being handled by PowerDVD and YXY. There is no switch between the devices and the projector yet, so I have to hand swap the cables. All three devices deliver S/PDIF audio to a stack of Rotel separates, and ultimately to Polk Audio towers, surrounds, and sub.


Front Venting:

The VT540's exhaust is on the front of the projector below/above and slightly to the left/right of the lens (depending upon floor/ceiling mount). The fan is fairly strong and blows most of the air at an angle less than 45d to the face of the projector. Unfortunately, the heat from this exhaust (especially after an hour or more) is far too great for placement of the P752 directly in front of the projector. I did not notice this issue for a few hours during my initial testing. Upon touching the P752... Yikes! That's hot! There was also a non-uniform focus to the display, which worsened as the experiment continued. It was not until the next morning that I noticed that about 1/2" of oil had leaked from the front plate (obviously a result of expansion due to the extreme heat).


I took a cross-section of EPVC and used it as an extension of the VT540's vent to help channel the heat further to the side. I also positioned the P752 about an inch further from the VT540 (which is not a problem since the VT540 has a small aperture). The results are promising and the P752 remained cool for about three hours. The corner closest to the vent area warmed a little, but nowhere near what it was previously. Focus remained linear for most of the test. A slight focus non-linearity was noted near the end of the test but I attribute that to the aforementioned warming (which will be completely corrected with the final duct design).


Be extremely careful in your duct's design. The VT540 fan blew my duct aside when it was leaning against the projector. To hold the curved EPVC section in place, I had anchored it between the board on which the projector rests and the bottom of the VT540 vent. This held the duct in place and worked very well in directing the exhaust flow. Unfortunately, it was too close to the projector (okay, it was touching it!) and over the first few hours of the test it had transferred enough heat to the VT540's faceplate to cause an expansion in the zoom lever mechanism. The lever seized! I moved the vent duct out a bit (holding its position with yet more temporary measures) and the faceplate slowly cooled. I checked it in the morning and there doesn't appear to be any long term effects. I imagine that if left long enough, zoom, lens, or some other damage could occur. Be careful!


Using my HTPC, I viewed portions of T2, a YXY vertically stretched Holy Grail, and a YXY pillarboxed Robin Hood (Disney). I also watched Leno in HD and some SD, both of which were sourced from the UM. I also watched Band of Brothers on HBO-HD. I also did some gaming. Overall, I am very pleased with the results. The LCD grid was all but eliminated, the image was definitely brighter, and the improvement in resolution was impressive. Each of these sources looked extremely good (okay, not G15 good, but as good as I have witnessed). Clearly superior than without the P752. There was some keystoning, but the VT540 is centered vertically on the screen tilting way down using front-floor projection mode (it is supposed to be below the screen from 16'). This positioning is for experimentation and it will eventually go on the ceiling. A quick run through of AVIA 16:9 anamorphic patterns showed some non-linear distortion (more on the squares than the complex hash pattern). Though again, my configuration is anything but perfect or final. I will do more accurate tests when I move the projector to a better location. My throw is 16' so I should be able to find a sweet spot .


I will be using YXY to handle letterbox and pillarbox requirements for DVDs. Either dScaler or the HDD200 will be used to handle SD sources originating from my NTSC satellite gear (leaning toward the HDD200 since I like to surf/work on the HTPC while watching TV - but not movies). With that handled and all of those images placed neatly at the horizontal center of my 2:1 DIY gray screen (except 2.35:1 movies which get zoomed out to the top/bottom and 8' wide), the only issue is other HTPC uses and their presentation location on the screen. I had entertained some, shall I say, "unusual" ideas for movable mounts to overcome the VT540's short zoom range and the P752 image drop. However, my current gaming involves games that do not appear terribly effected by the vertical squeezing of the 4:3 panel into 16:9. In fact, I rather like it since it provides a much wider - and immersive - large screen (100"+). Mostly I do racing, though chopper simulators are also interesting. The only oddity is that the gauges are ellipses, but that is really minor.


In the first P752 test, I ran NASCAR 4 and SCGT tracks and liked the feel. Given the simplicity of a fixed mount versus a motorized, n-degree-of-freedom mount, and since I'm moving in a year or two, I think I'll opt for the fixed mount.


More comments when I have time.



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[This message has been edited by Man E (edited 10-11-2001).]
 

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Thanks for the review Man E. I am patiently waiting for my Panamorph (and 2.35:1 Panamorph). Reading your review was helpful. Please keep us up to date as your system evolves.


Jeff
 
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