Film-Tech Forum ARCHIVE: M.D.I. 3D silver screen

my profile | my password | search | faq & rules | forum home

»	Film-Tech Forum ARCHIVE » Operations » Digital Cinema Forum » M.D.I. 3D silver screen (Page 2)

This topic comprises 2 pages: 1 2

Author

Topic: M.D.I. 3D silver screen

Andrew Lee
Film Handler

Posts: 99
From: Oakville, Ontario, Canada
Registered: Jun 2002

posted 10-05-2009 11:17 AM

Well it would take a 3D screen topic to bring me back to this board. I find it necessary to comment on some of the posts.

In no particular order:

- The MDI screen at Zion is a great screen and is not a lenticular surface. Mark, you did an awesome job of installing that stuff in record time.

- However,most MDI silver and a few 1.4 and 1.8 do have a lenticular pattern embossed onto the vinyl prior to painting. It is not the old style lenticular vertical pattern that some of you remember. It is a very small diamond pattern. Lenticular can refer to any pattern, embossing, or texturing on a screen surface that acts in a way to intentionally direct light differently than a flat surface.

- The combination of this pattern and the right paint distributes the light to a point that can diminish the hotspotting effect by spreading out and lessening the intensity of the light. Easier said than done but in essence MDI does have a lenticular screen (no BS Frank or used car salesmen).

- This is one of the rare times I would disagree with Steve. A proper custom lenticular design combined with the right coating can theoretically and has in one case completely eliminated the hotspot. Too expensive to make in the real world.

- Screen manufacturers have been trying to make silver and high gain lenticular screens for over 80 years. Making one that meets todays expectations of looking as good as a matt white screen is simply close to impossible. The end product would be too expensive if you could solve this issue.

- As long as the coating is of a metallic base it will maintain polarization on a lenticular surface as Steve mentioned.

- Mark, why can't you paint a lenticular surface? Then again if you are refering to the multi-layered ribbed screen surface I just thought of, you would be correct. When I am referring to lenticular, I am not referring to the ones that have optical films.

- Frank, just to reiterate, yes a silver lenticular screen with the right pattern, depth and coating is the holy grail, it simply can't be done to it's potential without costing at least 10x what a silver screen costs today. If it was that easy, everyone would be making one.

Andrew

| IP: Logged

Alan Gouger
Jedi Master Film Handler

Posts: 501
From: Bradenton, FL, USA
Registered: Jul 2000

posted 10-05-2009 11:29 AM

I have found with any Silver or high gain screen visible pixel interaction from fixed pixel displays ( all digital projectors ) that looks like shimmer or sparklies that is not there with film.

By the way does anyone have a link to MDI screens. I could not find anything. Thank you.

| IP: Logged

Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12814
From: Annapolis, MD
Registered: Dec 1999

posted 10-05-2009 08:54 PM

Andrew

quote:
- This is one of the rare times I would disagree with Steve. A proper custom lenticular design combined with the right coating can theoretically and has in one case completely eliminated the hotspot. Too expensive to make in the real world.

I'll be happy to concede this, once I see your data. That is, I would want to see the same projector/lens with the equivalent of a PSA200 type chart to show how the hot spot has been "eliminated". A Torus screen can almost eliminate a hot-spot too...without lenticules but the bring other undesirable artifacts. A lenticule is going to control the light like a blinder on a horse...this will help prevent scatter but I don't see how it helps with the prevention of hot-spotting...which is cause by the very narrow scatter of the Silver screen. Cinerama used lenticulated screen material (by Hurley Screen Corp) to aid in stopping self illumination. However, rather than diamond shaped, they were box. They did a reasonably good job too as well as the louvered manner in which it was constructed.

I would presume you went with a diamond pattern rather than grid to avoid Morie patterns from digital pixels aligning on the same grid.

I would think there would also be measurable contribution of the lenticules to the sound as they would act like minature horns right in front of the perforations.

Interesting stuff, for sure...but I would want to see the data before passing judgment on how well it accomplished its goal and what possible unintended affects came out of it.

Steve

| IP: Logged

Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99

posted 10-05-2009 09:30 PM

Andrew,
I stand corrected and thank you for chiming in on this. I agree that I'd like to also see some data however anyone attempting taking a step like this is a step foreword in my opinion. One thing that bothers me a bit is the fact that you emboss first and then paint over the emboss. I just don't see alot of consistancy happenning there even with automatic spraying machines. Have you considered creating a coated surface first and then emboss as in the old days? That would also bring you back to being able to do the ideal shaped lenticles. Once a screen is painted the paint is going to run a bit even if it's microscopic amounts and so on then the lenticles you have ambossed are not what you intended them to be. Even a textured paint or varying texture across the width with something in it that helps even out the hot spot? I seem to remember reading that the original D-150 screens had varying size lenticles as you went across the screen to control reflection vs angle. IMHO in this technological age something like this should still be easily possible. D-150 did this on a small scale and screen companies are making silver screens like never before... IMHO, the technology just needs to go in reverse to catch back up with today!

Mark

| IP: Logged

All times are Central (GMT -6:00)

This topic comprises 2 pages: 1 2

Printer-friendly view of this topic

The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion and agrees to release the authors from any and all liability.