Home Top 10 Database Reviews CalculatorCalc Lamps Buyer's Guide

Home Theater Projector Buyer's Guide

What about Installation?

The best projector on earth is useless if it doesn't fit in your theater. To make projectors easier to use in a variety of rooms and help them accommodate different screen sizes, many projectors now incorporate long zoom lenses and physical lens shift.

Zoom Range

A zoom lens is able to make the projected image larger or smaller by shifting the internal optical elements of the lens. This allows a projector to deliver the desired image size from a range of throw distances. Some projectors have a very limited zoom range. For example, a 1.20:1 lens, sometimes noted as 1.2x, means the maximum image size is just 20% larger than the minimum size. On the other hand, some projectors have zoom lenses of 2.0:1, or 2.0x, meaning that the maximum image size is double that of the minimum image size. Such a lens provides a lot more flexibility to create the image size you want from the place you want to locate the projector.

Though long zoom ranges offer great flexibility, the projector's potential light output usually drops somewhat if you use the telescopic end of a long zoom lens. Some representative samples have shown lumen loss of 25% to 41% when using the lens's telephoto position, and light output drops off linearly--meaning that it will lose half as much light at the lens's midpoint, and so on. If you want to maximize light output, it is best to avoid the longest throw distance the lens will allow.

In your search for the right projector, first determine the size of the image you want on the wall. Then use the Projection Calculator to see if the model you are looking at will create that size image with the room size and throw distances you have to work with.

Lens Shift

Another feature that makes installation easier is lens shift. Lens shift is the ability to move the projected image up or down, left or right, while keeping the projector stationary. This makes it a great deal easier to place the projector where you want it, and adjust the lens so that the image fits your screen perfectly. If you do not have any lens shift capability, you will need to take extreme care to position the projector at the precise location demanded by its fixed throw angle.

If the projector does not have lens shift, one alternative is to tilt the projector such that the image fills the screen from the position you want to place the projector. However, this will result in a trapezoidal image. You can square it up using keystone correction, but this is something you should avoid if possible. Keystone correction causes the projector to use fewer pixels to display the image, which causes the projector to scale the image to fit the new smaller pixel matrix. This eliminates some of the benefits of using an HD projector to begin with, namely native display of HD signals, resulting in maximum detail and sharpness.

Vertical lens shift, which moves the projected image up and down, allows the projector to be placed at different heights and still properly light up your screen. The range of shift varies by projector, from a modest range of half a screen height to a maximum of about three screen heights. If you plan to install your projector on a rear shelf so that the projector is about the same height as the screen, you only need a modest lens shift range. On the other hand, if you plan on ceiling mounting your projector and having it throw the image downward to the screen, or using a high rear shelf, a more extensive vertical lens shift range is required. Without lens shift, it is sometimes possible to ceiling mount the projector in the precise location dictated by its fixed throw angle. However, this often requires the use of a drop tube to distance the projector from the ceiling to achieve your preferred screen height.

Horizontal lens shift moves the projected image from side to side, allowing the projector to be placed off-center horizontally from the screen. While horizontal lens shift is not normally as extensive in its range as vertical shift, it does allow for some movement, which is crucial if you cannot place your projector in line with the center of your screen. Horizontal lens shift can vary between 5% and over 50% of a projected image's width, and it is less common than vertical shift.

The availability of vertical and/or horizontal lens shift on a given model is noted in ProjectorCentral's database, but the specific range data is not. However, these specifications are always discussed in ProjectorCentral reviews. They can also be found in the Owner's Manuals, many of which are available from the projector's specification page in our database.

Previous Page
Next Page
Contents: Overview Aspect Ratio Resolution Brightness
  Contrast Installation Cost

Reader Comments(15 comments)

Posted Feb 28, 2011 4:17 PM PST

By bahha

Post a Comment Alert Moderator
thank you, your guide is helpful . I'm going to buy a projector now, I want to use at school for teaching.

Posted Jul 19, 2011 6:59 AM PST

By Vichu

Post a Comment Alert Moderator
Thank you. The article is very informative

Posted Jul 25, 2011 12:43 AM PST

By b.r.nath

Post a Comment Alert Moderator
a nice handy guide for all the buyers

Posted Jul 26, 2011 11:19 PM PST

By rman

Post a Comment Alert Moderator
wonderful guide.. Thanks!

Posted Sep 6, 2011 10:59 PM PST

By hussain

Post a Comment Alert Moderator

Posted Feb 24, 2012 2:29 AM PST

By sophie

Post a Comment Alert Moderator
Awesome list, thank you! I have been thinking lately that perhaps I should add Comment Luv to my sites. Just have not been sure yet what all the benefits are – does it make a difference in rank at all, or mostly in interaction on websites? I am bookmarking this page for convenience Thanks again for providing valuable content to your readers! [Link deleted by Projectorcentral]

Posted Apr 9, 2012 6:23 PM PST

By bill

Post a Comment Alert Moderator
thank you very much for making and sharing this guide (and the rest of the site's content, too). i've found it easy to follow and very informative. many thanks.

Posted Apr 18, 2012 2:46 AM PST

By narco

Post a Comment Alert Moderator
thanks for an informative and well written article.

Posted Nov 12, 2012 8:14 AM PST

By Ash

Post a Comment Alert Moderator
Thanks for a great article. The beginners like me can acutally now go out and search for the one we need. I am looking for one below $1200 with screen and ceiling mount. This article really is helping me narrow down on the selections and also helped understanding the importance of going for better screen. One suggestion...Please include a couple more sections, one for 3D compatibility and another for performance with gaming consoles.

Posted Jan 15, 2014 9:09 PM PST

By home theater

Post a Comment Alert Moderator
Great guide for everyone who is in planning to buy the home theater system. last year i am too confused in buying the best home theater system. After reading the products review and comparing home theater system in terms of technical specification, i find the best home theater system. [edited to remove link]

Posted Feb 4, 2014 3:02 AM PST

By Anil Samuel

Post a Comment Alert Moderator
Amazing article. I appreciate the effort. And thanking you all behind this site. I am from Germany And I want to buy one good projector for a charity association

Posted Feb 7, 2014 12:35 AM PST

By steven prentice

Post a Comment Alert Moderator
Fantastic breakdown for projectors thank you

Posted Feb 21, 2015 1:50 PM PST

By TheWiredFox

Post a Comment Alert Moderator
This guide is helpful, however it does not include any information regarding inputs, specifically '3D PC' vs. 'HD 3D' inputs. I currently have a 2D setup with HTPC and Blu-Ray switched through my receiver with HDMI. Upgrading to a 3D projector is the plan, and getting into specifics with '3D PC' vs. 'HD 3D' should be included in this Buyer's Guide. Thanks.

Posted Jul 26, 2017 2:47 PM PST

By Steve Hiegel

Post a Comment Alert Moderator
All the information needed to arm yourself with the information you need to buy a projector that fits your needs. Thank you for this resource.

Posted Mar 9, 2018 8:38 AM PST

By amedius

Post a Comment Alert Moderator
Awesome article if only I would have read earlier. I purchased a Epson tw6100 four years back and placed in the last corner way back 20 feet. Since its having keystone correction, I could adjust the image of 140 inch diagonal to get it perfectly aligned. Bluerays look sharp and very bright. I was happy with it. But after reading this article, I wonder if I would have placed the projector right in the center and just 12 feet from the screen, I could have got a better image, maybe still brighter and more sharper. Thanks for the article. My next projector placement will be a lot different.

Post a comment

Commenting on this article is easy and does not require any registration. Your email address is necessary for you to activate your comment once it has been submitted. It will not be shown to other site viewers. ProjectorCentral reserves the right to remove any comment at any time for any reason. Foul language is not permitted, nor are personal attacks. No HTML allowed. All comments should remain on topic.


Email Address:(used only to confirm your comment)

Your Comment:

(Enter the numbers as they appear to the left)