Film-Tech Forum ARCHIVE: Home theater vs Dci Cinema projectors

This is topic Home theater vs Dci Cinema projectors in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by George Murray (Member # 6991) on 11-13-2012, 04:56 PM:

Hi everyone, Im currently planning to build a high quality private screening room for private use. The screen Is roughly 10x18 feet and I was just wandering what everyone though one the d-cinema vs high end home theater debate. The home theater projector I would be looking at is the new sony vw1000es 4k vs any dci compliant 2k/4k upgradeable projector. My biggest issue is the contrast as I have noticed that most dci projectors struggle to produce good black levels with a 2500:1 contrast ratio while the sony vw 1000es has a 1,000,000:1 contrast ratio which would produce much deeper blacks. Any input is appreciated!

Posted by Steve Guttag (Member # 268) on 11-13-2012, 05:31 PM:

Watch out on the Contrast Ratio specification...anyone claiming a projector contrast ratio in excess of 2500:1 is flat out misleading. With present technology, it is impossible. A DCinema projector at 2200:1 or so is about the top of the range and THAT is a lie too. In truth, they struggle to get into the mid 500s and home projectors are even worse.

But how then do these companies boast the stupidly high numbers? Because there isn't any real regulation on it so the contrast ratio is a fictional set of parameters they set up themselves. So, what is the ratio between the brightest I could get the image with a whiter-than-white signal and essentially the lens capped.

What a home projector will do is modulate the light or iris (or both) to adjust the source light based on the current image being shown to make it brighter/darker. A DCinema projector wont do that because there is only one point where it is faithfully reproducing the image.

If you want to prove it to yourself. Have a test generator and put out a checkerboard pattern (white and black) and bring along a meter (and it will need to be a good one with likely a tube on its lens to properly filter out its OWN lens flare) and measure the light on the white square and then the black square...ideally, you can flip the pattern so your meter doesn't move (measure the same spot on the screen)...your ratio on that home projector is going to be something like 250 or so.

The white level is supposed to be 14fL. To get to 2200:1, the black would need to be down to .006fL. You'll enjoy getting a meter that would register that level accurately.

The DCinema projector is going to best a home projector on real Contrast, Color GAMUT and on down the line. That does not mean that a home projector won't be perfectly adequate running things like BluRay and HDTV and look superb.

Posted by Alan Gouger (Member # 543) on 11-13-2012, 11:49 PM:

Here is someone with a D-Cinema projector in their home.
The images on the screen look pretty good. Not that pictures tell the whole story but I dont see any lack of contrast.
http://www.dcicentral.com/forum/showthread.php?44-My-DCI-4K-Home-Theater

Posted by Cameron Glendinning (Member # 3516) on 11-14-2012, 12:45 AM:

For a fraction of the price of D cinema projector the JVC D-LIA 4k projector produces a stunning image at home, very close in quality in my opinion to the 3dlp technology found at the cinema. Well worth checking out for yourself!
Blu ray however is not as good a source as the D cinema file.

Posted by Monte L Fullmer (Member # 2797) on 11-14-2012, 03:12 AM:

Must be fun to be rich to afford a BARCO 23B unit, but ain't that a bit of an overkill for the size of screen in that screening room? Wonder if he has a server, or just using DVI/scaled VGA feeds for the time being.

Posted by Frank Cox (Member # 6258) on 11-14-2012, 10:44 AM:

Even if he has a server, where would he get the content?

As far as I know, DCP's aren't available for sale or rent to the public. Or am I wrong?

Posted by Scott Norwood (Member # 30) on 11-14-2012, 11:34 AM:

He could probably book older titles for home use. This is entirely possible to do with 35mm (though it generally requires calling yourself something like "the ABC film society," and not "Bob's screening room." I don't see why DCPs couldn't also be booked in the same way. No, it wouldn't be cheap, and he wouldn't likely have access to any first-run titles.

Also, if he is professionally involved in the production side of the industry, he may have access to DCPs. Or he could make them himself if he has access to production elements in electronic form.

Posted by Marco Giustini (Member # 4544) on 11-14-2012, 04:18 PM:

I used to have a JVC DILA projector. The massive contrast boasted is real, but as steve says, it's full on/full off. The ANSI contrast in a "bat cave" is more like 125:1 That annoyed me most, the contrast level was MASSIVE on low light scenes, but everything washed out when anything bigger than a small window was shining light (and, again, my HT was completely black).
That said, I measured a DP2000 once, the ON/OFF contrast was - as advertised - 2000:1, and the ANSI was 500:1, which is a noticeable improvement over 125:1.
Don'e even mention irises please. [Frown]

Posted by Bajsic Bojan (Member # 4928) on 11-15-2012, 01:22 PM:

In my limited experience, it has been impossible for us to get dcps or kdms for dcps we have on our servers, for films that are NOT first run. Anything older then 12 months, we would be really lucky to get KDMs for. Be it either from local distributors or from deluxe or other global distributor.

We don't have any vpf deals or anything, might that be a case for not being able to screen older titles?

I believe we are not the only case. In a curious case on the (if i remember correctly) german forum people cannot get a dcp for "Avatar 3D" of all things. Are the dcps even stored anywhere? What is the reason for such 'blocking'? Who knows...

sorry for slight offtopic.