Lens Shift to the Rescue

November 7, 2006

ProjectorIf you’ve ever scoured over front-projector specifications you’ve no doubt noticed lens shift mentioned right alongside the contrast, brightness and resolution designations. Lens shift isn’t something you’ll give much thought to after the installation is complete but it could very well make or break that installation in problematic applications.

All things being equal we wouldn’t even need lens shift, which is to say if we could place our projectors where ever and how ever necessary to achieve the proper horizontal and or vertical alignment to the screen, the need for lens shift would never arise. However as we all know, no two rooms are equal and real world limitations often dictate less than optimal compromises in our front projection installations.

Those less than optimal installation scenarios are where lens shift can really save the day; let me give you a few examples. One of the most obvious examples is lens offset, you’ve no doubt noticed that the lens of some projectors are smack-dab in the center of the housing while others are offset a few inches. This wouldn’t be of much concern for a first-time installation but what if you wanted to use the same mount/location and your new projector utilizes a centered lens versus the offset lens of your previous projector?

Provided the throw distance is in the same range, simply mount the new projector on or at the old projectors mount/location and adjust the horizontal lens shift a few inches. Viola, you’re ready to enjoy your new projector without the need to relocate the wiring, or even change the ceiling mount. (provided their similar enough)


Aside from the centered versus offset scenario, vertical lens shift can be even more useful in many cases, such as, in lieu of having to place your screen at a height dictated by the drop provided by your projectors mount. If your within the tolerance provided by the new projectors vertical shift, in many cases you can simply place the screen at your desired height and then drop the image down a bit to strike the screen at just the right spot.

As mentioned above if you’re able to install your screen and projector without obstruction within the predefined throw distance and vertical lens offset, a projector with lens shift may not mean all that much to you. However if you’ve already determined you’re going to experience some constraints due to your desired mounting location, a projector with lens shift may very well be worth the difference in cost over one without.



Posted by Bryan Greenway | | Filed Under Home Theater Projectors


Comments