yamaha DPX-1 with perforated screen?! (1 Viewer)

[michael_m_b]

hello guys!

i posted this thread in another forum, too, but by now i haven´t received any responses... because of the fact that i´m in a bit of a hurry getting a screen for my newly made ht-room i thought about posting my questions here at the htf.

well, here it goes:
i recently bought a yamaha dpx-1 at a bargain price and thought that the results with this dlp projector were pretty cool ( even though there is a newer model out there....well, that explains the price drop of the dpx-1)...

now i have a few questions:

i emailed a HT dealer about dlp projectors and micro-perforated screens (stewart firehawk thx microperf) and the response was that it was possible to hook up the dlp projector and the stewart screen without having the moire effect. can anybody confirm this?

well, the next question is about other screen-manufaturers...what about da-lite screens? they are A LOT cheaper than the stewart ones and i hear that the performance isnt all that bad? can you comment and recommend other screen manufacturers?

well, as a newbie with dlp projectors, screens, and so on i´d be very happy if you could give me some advice and help me with my situation here...

thanks in advance!

 

[Jason Charlton]

I'm by no means a front projection expert, but my understanding of microperf screens was that their primary benefit is that they allow the center channel speaker to be placed directly behind the screen, as per THX specifications (the microperforations creating a nearly acoustically transparent screen surface). I'm somewhat at a loss as to how the screen material itself would be capable of eliminating something like Moire - which is often the result of a combination of the source material, display device, comb filters, cabling, etc.

When dealing with DLP projectors, I believe the most important consideration is the screen color - using a gray colored screen (like the Stewart Firehawk) greatly increases the percieved contrast. I know Da-Lite has a comparable gray-colored screen material that is recommended for DLP projectors, but I can't recall specifics off the top of my head. A lot of people have had great success with Da-Lite screens as well as home-built screens for much less than the cost of a Stewart.

-Jason

 

[michael_m_b]

thanks for your reply...



my main question is:
is it possible to use a perforated screen with the dlp projector without having the moire effect? i mean, theres actually not much you can do than experiment a bit with the space between the screen and the projector....

one of the retailers i emailed sent me the following info:

"...DLP and microperforated screen works perfectly fine if you know how to place the projector. after your order you get specific details on how to configure the projector to get rid of the moire effect"

well, that didn´t exactly helt THAT much


can somebody bring some light into this?

 

[Matthew Todd]

Michael,

I've read that the moire is caused with DLP and microperf screens because of the interaction between the tiny holes spacing at the screen and the pixel structure of the projector.

I've heard that it's a sort of hit and miss if you will notice moire with a particular projector and a Stewart microperf screen. I think Stewart themselves says that there is a risk of moire with screen widths of less than about 92 inches wide when using a DLP projector (I think with a 1280x720 resolution).

I think that with lower native resolutions, you can go to lower screen widths and not have a problem.

I've also heard that the other screen manufacturers use a different perforation density, and so they may not exhibit moire. Woven screens (I think there are a few suppliers out there) do not exhibit moire, and are still accoustically transparent.

That is about the extend of my knowledge on the subject!

What screen width were you planning to use?

Matt

 

[michael_m_b]

Stewart Luxus Deluxe Screenwall
Firehawk Microperforated
2997mmx1676mm

Dalite Cinema Contour
295x165cm
HC Cinema Perf

Dalite DaSnap
295x165cm
HC Cinema Perf

those were the different types i requested in my inquiry at my local deales...
on the avs-forum i found a thread about ClearPix™ by Screen Research™, but as a student this one and the stewart are out of my league at the moment...

but imho a acoustically transparent screen is a tentpole for every home theater....thats why i keep on searching for a solution to my problem

 

[Neil Joseph]

That is exactly what happens and why moire is a possibility with all digital projectors, not just dlp. If you can find anyone that uses a digital projector with a 1280x720 resolution (lcd or dlp) in combination with the screen you seek then the question can be answered properly. Personally, I would not look to a perforated screen unless I was using a crt, but that's my own personal preference.