Film-Tech Forum ARCHIVE: My First Time (watching a DLP presentation)

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Posted by Mitchell Cope (Member # 32) on 03-23-2002, 06:44 AM:

Last week I saw my first DLP presentation. I normally avoid these types of things because I'm a big fan of 35/70mm film. This time, my wife wanted to catch an earlier show of "Showtime", so there I was.

I'm not going to talk about artifacts or resolution. I actually thought the picture was good with the following noted exceptions. I noticed that DLP may not have been able to produce some low light areas. That was a slight bother. The thing that really got me is that the closeups on people made their faces seem wider than normal. I thought De Niro's closeups made him look like Jake La Motta out of "Raging Bull". What's the deal with this? How could this be? Everything else looked pretty normal, but closeups went down the tube. Hollywood is not going to like this.

Posted by John Anastasio (Member # 607) on 03-23-2002, 07:47 AM:

Sounds like a problem with the DP, not the DLP. I don't see how the mode of projection would have any effect on a closeup. As far as the contrast ratio is concerned, there's no doubt that DLP cannot yet match that of film. See the latest issue of the SMPTE Journal for a great article on a subjective comparison done between film and digital projection. They ran several films fipping between reels (reel 1 - 35mm, reel 2 - DLP, etc ...not telling the audience which was which) The only area in which some viewers like DLP better was in perceived brightness on the screen. Contrast on the DLP was a dismal loser as well as sharpness. Highlights burned out and shadow detail disappeared. It ain't there yet, folks.

Posted by Mitchell Cope (Member # 32) on 03-23-2002, 08:10 AM:

The "face fatness" was noted in the trailers as well. Though I couldn't note this problem in regular shots, could the projectionist have unsqueezed the image too much? Again, I think I would have detected that in all shots.

Posted by Ken Layton (Member # 133) on 03-23-2002, 10:52 AM:

Since it is a video format the video projector must have the same controls as tv sets and monitors: "Horiz Size" (width) and "Vert Size" (height).

Posted by Paul Linfesty (Member # 214) on 03-23-2002, 11:43 AM:

This may be the same problem I observed during a DLP showing of Mission To Mars. The image was definitely streteched out more than it should have been.

Posted by Steve Kraus (Member # 476) on 03-23-2002, 11:51 PM:

Ken suggested:
>Since it is a video format the video projector must have the same
>controls as tv sets and monitors: "Horiz Size" (width) and "Vert
>Size" (height).

Perhaps but not necessarily. Remember, this is not like a CRT where one can adjust size simply by varying the scan voltage & current.

After decompression the DLP data consists of intensity values specific for each pixel on the red, blue, and green DMD chips. (As the micro-mirrors themselves are 1-bit on/off units, gray scale is achieved by varying the duty cycle.) If there is an ability to resize it would have to be accomplished by a local processor re-rezzing the image like you would in Photoshop. That would probably cause loss of resolution and would certainly be wasting pixels which are already in short supply. So it seems unlikely although someone else will have to give the definitive answer.

Posted by Joe Redifer (Member # 3) on 03-24-2002, 01:54 AM:

I would think that it would be much easier to notice the shots being too wide non-telephoto shots. People in the distance would look very awkward. Closeups would be harder to notice such an effect on.

Odd.

Posted by Richard Topping (Member # 871) on 03-24-2002, 07:41 AM:

I think that the presentation you must have seen must have been set up poorly from the installation. I have just been setting up a cinema in Hungary and a DLP was installed in their. Kinoton Console and Barco Head.

The first film playing was Monsters Inc. (in english though!) and the picture was almost perfect, everything looked very good and was only when you got close up could you notice the pixels. It is still not up to standard of 35/70mm but it is getting closer!

I was speaking to the rep. from technicolour who set up the film, and some interesting facts (if you did'nt know them already) There are 3 DLP chips in the head, each chip contains 1.2 million mirrors, and like said before they are in state 0 or state 1 (open or closed) differant light scales are acheieved by turning from state 0 to 1 and back again quickly. The mirrors are moved by electic pulses sent by the QBit (the bit that runs the film).

Hence 3.6 million mirrors = 3.6 million pixels. For every 1000 chips made only 1 have every single mirror working and therefore can be used in a DLP cinema projector. The other 999 have at least one pixel missing.

Posted by Gordon McLeod (Member # 33) on 03-24-2002, 08:27 AM:

One reason closeups may look more jagged as curved lines of facial contours will tend to epand across more of the screen so there apparent resolution should increase.
Just think how bad Bardot would look with jaggy curves

Posted by Jerry Chase (Member # 660) on 03-24-2002, 08:59 AM:

Just a thought- I wonder if the micromirrors have the same aspect ratio as the devices recording the image. This could have the effect of "fattening" things. I could understand the MMs needing to be something other than square. There has to be a tiny gap for the mirror to vibrate without affecting its neighbors. That gap might be larger on the axis that has the direction of rotation.

If this is the case, it could be a difficult problem to fix electronicly. Leaving out every Xth vertical grid line of pixels would create jaggies and uneven movement. A slightly anamorphic lens would be the proper solution. -Again, this is just speculation, I don't know the tech specs. of the MM chips or CCDs or whatever is being used.

Posted by Richard Fowler (Member # 893) on 03-24-2002, 09:06 AM:

The DLP cinema chip ( at the moment ) is basically 1.33 / 1 and requires anamorphic adapters for both common formats.....the mirrors vibrate at one axis.
Richard Fowler
TVP-Theatre & Video Products Inc. www.tvpmiami.com

Posted by John Pytlak (Member # 331) on 03-24-2002, 06:35 PM:

Actually, the "native" aspect ratio of the 1280x1024 pixel DLP-Cinema projectors is only 1.25:1. They use a 1.5X anamorphic lens for 1.85:1, and a 1.9X anamorphic for 2.39:1.

------------------
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Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
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Posted by Paul G. Thompson (Member # 655) on 03-25-2002, 07:16 PM:

The first DLP persentation I saw was at ShoWest, the screening of "Windtalkers". The sound was awesome, but I was not impressed with the picture. Something seemed to be missing. I think I would rather see that movie on 35mm.

Posted by Aaron Haney (Member # 747) on 03-25-2002, 07:26 PM:

quote:
Hence 3.6 million mirrors = 3.6 million pixels.

Actually, it takes three mirrors to make one pixel (R-G-B), so that's still only 1.2 million pixels. And the color components are aligned so that they are displayed directly on top of each other, so there isn't even any chance for sub-pixel information.

Posted by John Pytlak (Member # 331) on 03-26-2002, 08:37 AM:

Paul said: "The first DLP persentation I saw was at ShoWest, the screening of "Windtalkers". The sound was awesome, but I was not impressed with the picture. Something seemed to be missing. I think I would rather see that movie on 35mm."

I saw the "Windtalkers" digital cinema presentation as well. I was very disappointed in the handling of the highlights --- very light areas of the scene (sunlit rocks, the highlights on Nicholas Cage's nose) tended to "clip" in a video-like fashion. The black areas were not truly black --- e.g., the night scene where the drunken Cage is in the graveyard had a "foggy" appearance. Sitting in the front row of the crowded Les Theatre des Arts, I could also see the pixel structure in light areas, and "jaggies" in the titles.

Posted by Greg Pauley (Member # 503) on 03-26-2002, 12:01 PM:

I also watched "Windtalker" and would agree with John about the black not being black. It looked like watching a TV with the contrast out of adjustment. I really don't think the average customer would ever notice this and overall the picture looked sharp and bright where I was sitting (about halfway back). I just don't get the same feeling watching digital as I do with film. It's almost like digital is too sharp, bright and perfect that gives it a harsh feeling. Again, this could just be a mental thing with me and may not affect the average customer.

Posted by Randy Loy (Member # 112) on 03-26-2002, 01:02 PM:

Greg, I haven't seen a digital demo yet but I'd been wondering if it might have a harsher look than film, something akin to comparing TV shows shot on video to those shot on real film. I realize that we're dealing with digital, not video, but if they have some of the same characteristics it may be less than desirable and show at the box office.

I also don't get the same feeling from video as I do with film. In recent years I've found myself actually channel surfing past TV shows shot on video, preferring the softer, more comforting, look of film.
Maybe it's a mental thing with me too (or maybe I'm just "mental" ), but I wonder if movie goers will find films projected from a digital source less pleasing. I guess it's too early to tell, at least until the digital projection folks have gotten all the bugs worked out of the technology.

Come to think of it, didn't Roger Ebert recently suggest that digital projection may not have the same feel as film projection?

Posted by Daniel Boisson (Member # 1027) on 03-27-2002, 08:23 PM:

I just saw ice age today at the Ziegfeld. The sound was amazing, but the picture wasn't anything impressive. I doubt a majority of the movie goers will be able to tell the difference. I think its something you would have to be looking for, kinda like the changeover.

The projectionist at the Ziegfeld said when they run a DLP movie, they run the same in film at the same time, they don't really trust the DLP too much yet.

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3% Body Fat. 1% Brain Activity.

Posted by John Hazelton (Member # 898) on 04-03-2002, 10:26 PM:

Randy Loy wrote:

quote:
I realize that we're dealing with digital, not video

It is video, though--it's digital video. It's isn't NTSC or PAL, but it is video. Keep in mind that digital isn't a noun, it's an adjective. Calling anything "digital" is only providing half the info needed to describe it.

Current Digital Cinema presentation use 24fps video, either 1280x1024 progressive scan or SF.