Axiom Home Page Forums General Discussion Home Theater HD front projection??

I see rainbows very badly on RPTV DLP tv's but have never seen them on a FP DLP projector....very odd.

Sushi:

I just read this entire thread about 2 days ago for the first time. I may have to experiment w/ some metallic paint here shortly. Consistency looks like it would be the only problem with a DIY silver screen.

Try this thread. Some people have gotten a nice system going something like 50 silver 40 glaze 10 white something like that

http://www.avsforum.com/avs-vb/showthread.php?s=&threadid=267756&perpage=20&pagenumber=1

I tried fabric with little success. I'm opting for a Dalite hipower myself and forget about the troubles.

Yup, Saturn, I can HIGHLY recommend the Da-Lite High Power for anybody who:

(1) plans for a untensioned pulldown. It's a must -- no visible wrinkles.

(2) likes brighter, more vivid, yet still film-like image.

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I see rainbows very badly on RPTV DLP tv's but have never seen them on a FP DLP projector....very odd.

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Assuming that the RPTV and FP you watched use the same color-wheel speed, the reason may well be as simple as because of the brighter RPTV image. In my own experience, the rainbows tend to get worse with increased image brightness.

Theres no wrinkles in the untentioned version of the hipower?

My cheap ($160 CDN) Matte White Bretford projection screen doesnt do my picture justice.

Waiting for the new place to be setup before I buy the Hi Power permanent screen.

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Theres no wrinkles in the untentioned version of the hipower?

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Saturn,

First, the High Power fabric uses a very thick base material. That certainly helps it from developing bad wrinkles/waves when used untensioned.

Second, and more importantly, the unique retro-reflectivity of the High Power really makes the minor wrinkles, if any, COMPLETELY invisible in the projected image. Basically, retro-reflectivity dictates that the image brightness (reflectance) is determined solely by the geometrical angle between the projector and your head, and is independent of slight undulations of the screen plain.

Also, retro-refectivity ensures that the image brightness is perfectly uniform across the screen, wherever you are watching it from. Absolutely no hot-spotting, sparklies, nothing. It's almost magical.

[FYI, retro-reflective surfaces throw the projected light right back at the direction of light source, rather than toward the opposite direction like a regular mirror does. Retro-reflective materials are used in traffic signs and road marks, so that the light coming from your car's headlamp is thrown right back toward you.]

Great. That was an easy explanation. That long thread I saw on avsforum about pros and cons on the Hipower and then this scientific explanation of how light bounces of the reflected bead on the surface etc etc...that was a scary thread.

Hi sushi, all,

Fascinating discussion, especially the screen material shots. From an old darkroom film guy, the silver screen image is lousy. All the detail in the pistols and stamens is burned out.

The best balance and detail is the gray, although the white is quite good.

I haven't seen enough of LCos yet to comment, and I don't think I'll make it to CEDIA this year.

CRT is still the reference because it's had 75 years to mature.

All points made are accurate (having a dark room being the key).

Spiff--of course we all want film-like resolution, but it will always be VIDEO, because the gradations of scale in bright to black and color with optical film projections are really quite spectacular compared to video. I was reminded of this seeing "Swimming Pool" the other night. A new print, beautifully projected. It is simply stunning visually. Don't know who the lighting and cinematographer were. I have never seen skin tones like those of the young actress by the pool (exept in real life, ha, ha).

By comparison, even professional DLP cinema has a kind of video luminosity that, while appealing, is quite different from optical film, and in my judgment, not as real. It's still enjoyable, however.

As to 720p and 1080i, yes, the difference is there but it isn't dramatic, and you have to look for it.

So, the goal is to find a front or rear-projection technology that most closely rivals the best film projection.

Regards to all,

Yeah I'll chime in here on the screen...I've had marginal success with the silver/glaze/white DIY screen on blackout cloth. I didn't go out and buy the professional sprayer and such - I just used a fine nap roller onto blackout cloth. The results were nice. There's a couple of spots I went back with the roller before they were dry. That resulted in areas that appear lighter in very bright scenes. I think if I gave it another shot I could get it pretty even and with the improvement it gave me in contrast it was worth the $50 investment. I did a side by side with plain blackout cloth and the difference in dark detail was noticable.