Home Theater Projector Buyer's Guide

What is Contrast?

Contrast is the difference in brightness between the brightest and darkest parts in an image. The greater the difference, the higher the contrast.

Why is Contrast so important?

With business projectors, lumen output is of primary importance, and contrast is a secondary concern. Home theater projectors are the exact opposite. Contrast is arguably the single most important measurable quality in a home theater projector. A high-contrast projector produces a picture with a deep black level and clearly defined shadow detail. Contrast, in essence, gives "depth" to video images. A projector with excellent contrast can make a two-dimensional image appear almost three-dimensional.

Contrast Ratios

The contrast ratios noted on a projector's spec sheet can be reported in one of two ways. If it just says "Contrast," it usually indicates On/Off contrast, which is the ratio of the whitest white and the darkest black that the projector is capable of producing. If it says "ANSI contrast," the ratio has been determined by displaying a checkerboard pattern of white and black squares and measuring the relative brightness of each. On/Off contrast is always a much larger number, and more typically listed on projector spec sheets, but ANSI contrast is a somewhat more accurate representation of what your projector is actually capable of displaying in any given scene. Note that neither of these measurements tells the whole story, and only taking both numbers into account gives even a moderate approximation of a projector's capabilities. To really know what a projector is capable of in relation to other models, either find a way to see it in person or read our Projector Reviews.

What about a dynamic iris?

A dynamic iris is a device built into some projectors that sits between the lamp and the lens. Many times per second, the projector evaluates the overall brightness of the image being projected and then opens or closes the iris to allow more or less light through.

A good dynamic iris will improve on/off contrast. Dark scenes will appear darker, while bright scenes will appear brighter. The on/off contrast rating will be based on the whitest white with the iris opened, and the blackest black when the iris is closed. Dynamic irises have no effect on ANSI contrast, though, so a projector with a lower contrast rating may appear higher in contrast in any given scene. As with ANSI lumen ratings, it is best to take official contrast specifications with a grain of salt. They can be highly misleading.

Dark Room Needed for Best Results

You've noticed that commercial movie theaters are dark, including dark-colored, non-reflective ceilings and walls. That is because any front projection system looks its best when there is no light in the room; this includes stray light from the screen that reflects off the walls or ceiling. Once you introduce light into the room, that light will make blacks look more like dark gray. This reduces the contrast of the image, making it appear flat or washed out. This will happen no matter what the contrast capability of your projector is.

Though the ideal viewing room is dark, most people don't want to darken the walls and ceiling of a living room or multipurpose room just to get ideal theater conditions. Today's high-contrast gray screens help to improve black level when there is some ambient or reflected light in the room. For the best possible image quality, though, take whatever steps you can to eliminate ambient light and reduce the reflectivity of the room's walls and ceiling.

Contents: Overview Aspect Ratio Resolution Brightness
  Contrast Installation Cost

Reader Comments(13 comments)

Posted Feb 21, 2015 1:50:24 PM

By TheWiredFox

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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 Feb 7, 2014 12:35:37 AM

By steven prentice

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Fantastic breakdown for projectors thank you

Posted Feb 4, 2014 3:02:17 AM

By Anil Samuel

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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 Jan 15, 2014 9:09:56 PM

By home theater

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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 Nov 12, 2012 8:14:12 AM

By Ash

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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 Apr 18, 2012 2:46:38 AM

By narco

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thanks for an informative and well written article.

Posted Apr 9, 2012 6:23:14 PM

By bill

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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 Feb 24, 2012 2:29:49 AM

By sophie

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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 Sep 6, 2011 10:59:55 PM

By hussain

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THANKS FOR SHAIRING THE MOST BENEFICIL INFO ABOUT TODAYS CONFUSING PROJECTOR MARKET.YOU HAD MADE ME VERY COMFORTABE TO BUY A GOOD PROJECTOR WITH OUT FALLING IN THE TRAP OF ALL THIS CONFUSING REVIEWS AND MISLEAD MANUFACTURE ADVERTISING.TANKS A LOT.

Posted Jul 26, 2011 11:19:01 PM

By rman

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wonderful guide.. Thanks!

Posted Jul 25, 2011 12:43:47 AM

By b.r.nath

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a nice handy guide for all the buyers

Posted Jul 19, 2011 6:59:31 AM

By Vichu

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Thank you. The article is very informative

Posted Feb 28, 2011 4:17:58 PM

By bahha

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

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