CurtPalme.com Home Theater Forum

AFryia · Posted: Sun Nov 18, 2012 12:58 am Post subject: Keystone

I'm curious.

Does the JVC D-ILA projector have any optical keystone or lens shift or is keystone all digital?

Is a typical JVC setup for a certain projection angle 10-15 deg. maybe? Or are you forced to use digital keystone?

CIR Engineering · Posted: Sun Nov 18, 2012 3:34 am Post subject:

There is no optical keystone on a JVC.

Digital keystone ruins 1:1 mapping and really screws up the image quality. It should be totally avoided. The only reason it's their is so that incompetent installers can mask their incompetence.

craigr

**AnalogRocks** · Posted: Sun Nov 18, 2012 5:07 am Post subject:

AFryia · Posted: Wed Nov 21, 2012 9:29 pm Post subject:

WanMan · Joined: 19 Mar 2006 Posts: 10270

Screen tilt?

CIR Engineering · Posted: Thu Nov 22, 2012 6:20 pm Post subject:

ecrabb · Posted: Thu Nov 22, 2012 7:01 pm Post subject:

Guys... "Optical keystone correction" IS lens shift! So, the JVC most definitely has "optical keystone correction"!

The JVC is one of the more flexible (for the price) projectors with a long zoom range of 1.4-2.8:1, plus both horizontal and vertical lens shift. All are motorized, and there's a memory save/recall so you can save presets for different size/shift of the projected image, i.e. scope and pillar-boxed 1:78 on a scope screen.

The zoom has an atypically big range of 1.4-2.8:1. The vertical lens shift range is also big - about 80% of the screen height plus or minus, and the horizontal range is 34%. Using one does reduce the range of the other, so ideally mount the projector on the screen centerline.

As Craig mentioned, there is no good reason to mount the JVC's at anything other than perpendicular to the screen, and you certainly would want to avoid any digital keystone at all costs.

There's a JVC hanging in my theater these days, so if you have questions, ask away. Wink

SC

ecrabb · Posted: Thu Nov 22, 2012 7:06 pm Post subject:

Here's a section from the JVC manual on lens shift... You can see how big the shift range is.

Happy Thanksgiving!

SC

AFryia · Posted: Fri Nov 23, 2012 4:16 pm Post subject:

ecrabb · Posted: Fri Nov 23, 2012 6:20 pm Post subject:

Yes, mine is ceiling mounted. No tilt - my screen is exactly as it was with my g70: perfectly plumb.

Unless you specifically wanted to introduce some tilt, you wouldn't have to.

Personally, I can't really see any good reason for it, unless for instance your screen was well above the normal height relative to the viewers.

SC