Entry Level Home Theater Projectors Compared: Image Quality
Unlike the individual reviews of these home theater projectors, I'm going to combine my comments on image quality with related issues like calibrating the projectors, pixel visibility, the rainbow effect, and the screen door effect.
Let's start with the pixel visibility. All of today's projectors (except very expensive CRT types), are "fixed pixel devices". That means that there is a pixel structure you can see, if you are close enough. Sit too close, and you not only see the individual pixels, but you can also suffer the screen door effect, which makes the picture look like you are peering through a screen door. Worse, with the right type of image such as small vertical objects like grass on a football field, if close enough, you get a sort of patterning (not unlike a moire pattern), which degrades the image.
Because these are all "low resolution" projectors - all 854x480 pixels, often referred to as 480p projectors or EDTV resolution, their pixels are inherently bigger and more visible than higher resolution, more expensive projectors.
That said, DLP projectors have significantly less visible pixels than DLP projectors. For that reason, you would want to sit further back if you are watching the Epson Home 20, than the other three. (In fact, the pixel issue, was about the number one reason the Epson didn't get our Hot Product Award.)
Immediately below, are closeups from the boathouse image that show the difference on the word Schuykill. The first is LCD - from the Epson Home 20, the second is from the IN72. The pixels are the same size, but more distinct, and therefore more noticeable, on the LCD projector.
To get a real idea as to the significance of the differences, get both of these visible on your screen at the same time and start backing away from your monitor, you'll discover that with the DLP (InFocus), the pixels really become less noticeable before the Epson.
Epson Home 20
Most people don't mind sitting at a point where the pixels are "barely" visible, and mostly only in bright stationary parts of the image. For the DLP projectors that means sitting almost twice the screen width back, which for our theoretical 100" diagonal screen, would be about 14 feet back. For the same level of visibility you would be about 17 feet back with the Epson. If you like, or need to, sit closer than those distances above, you are almost certainly going to be happier with a DLP projector. (The kids probably don't care at all.)
The rainbow effect, is something that only relates to the DLP projectors, since they have a spinning color wheel. A very small percentage of the population will detect flashing rainbow colors, usually only occasionally, and some of those don't notice enough to find them detracting. Some of those, however will not be able to watch due to the rainbow effect. Remember, most home theater projectors are DLP, which tends to confirm that the rainbow affect is a problem for only a very small group.
Now that we've cleared that up, it's time to get down to the picture quality itself, excluding screen doors, rainbows, and pixels.
Projectors come in two other flavors - those with good to great color accuacy out of the box, and those that definitely can use some adjustment.
In this group of four, three do a great job out of the box. (I'm talking about for normal movie watching). Of these, the InFocus and Epson are very good. The BenQ W100 is close behind. Most people will be more than satisfied, just turning them on, popping in a DVD and enjoying the picture. The Optoma H27, however tends to favor green, not greatly, but enough to make flesh tones rather pale, and the green tends to be a little noticeable in shaded flesh tones, like the neck. My phrase is: "A little green around the gills."
The solution for the H27 is to pick up a good calibration disk, such as the AVIA disk which tends to sell around $39-$49. It's designed to be easily used by beginners, and only requires about one hour of your life to go through the tutorial, and calibrate the projector. The difference is rather significant. Once calibrated the image of the Optoma H27 is essentially second to none.
"The Holy Grail" of home theater projector performance is having great "black levels". Translated, that means that the projectors get very close to being able to produce black. (Only CRT projectors reallly can). The better the black level, the darker, the darkest grays the projector can put on the screen, so everything that is supposed to be black, ends up that level of gray. If a projector doesn't get very close to doing black, then much of the very dark parts (shadow details) get lost.
Generally, high contrast ratios, is an indication of black level performance, but that has changed in the last year or two, as techniques such as irises that dynamically adjust from frame to frame, and lamps that adjust brightness from frame to frame are used in some projectors to lower black levels when they can. The end result, high contrast ratios, can be misleading.
In the search for the blackest black one of the four projectors stands out, and that is the InFocus IN72, it's blacks are very impressive for such a low cost projector. Not quite as good, is the Optoma, the difference is definitely visible, but the H27's performance is still very good in this regard. Trailing the H27, next comes the BenQ, with decent but not impressive blacks and shadow details, and lastly, the LCD powered Epson. Inherently LCD projectors have trailed DLP projectors in this regard, which is why they are more likely to have "AI" circuitry controlling irises and lamps. The Home 20, however claims a low 1000:1 contrast ratio, and does not rival the others.
Let's look at some images:
Here are the four projectors tackling the image of Arwen from Lord of the Rings. All images were shot with the same digital camera, but at different times. Slight differences in brightness are normal in the attempt to get the best exposure, and do not indicate which projectors are brighter than others.
Arwen - Lord of the Rings (DVD)
Epson Home 20
Our next set of images is from a HD source. Keep in mind, though that these are not HD resolution projectors:
Boathouses - HD from D-VHS tape
Epson Home 20
You'll note from the two sets of images above, that the BenQ W100 has the strongest blue content. Of these projectors, none were calibrated for these shots, except the H27, for which a very basic calibration was done when originally reviewed, and the results of those numbers were used for the shots taken recently with the unit Optoma sent me for this comparison. (As expected, the calibration numbers from the original, are not dead on). There is variation from projector projector within any brand, due to variations in the lamps, etc. I found my original settings to be a little strong on red, at the expense of some blue.
Two more sets of images - First a look at black levels with a scene of a starship from the 5th Element, and then one more look at flesh tones, with an image of Gandalf.
In the starship image you can easily see the difference in black levels (although you will mentally have to adjust for the differences in brightness, and that there are 3 different frames between the 4 images). Please note, in each of these sets of images shown on this page, the images shown here may not be the exact same image found on the original reviews, as here, I picked from the bracketed images, the ones that were closest to the same exposure.
The 5th Element - Starship - (DVD)
Epson Home 20
My conclusions here, are that the IN72, definitely has the advantage, and the Epson Home 20 definitely has, by a noticeable margin, the least black, blacks. The Optoma is falls between the InFocus and the W100, however I should note, that only the Optoma offers AI frame by frame adjustments. Unfortunately, the DVD player's pause or frame advance icon on the screen definitely affects the AI. Since that pause indicator is full white, the Optoma cannot adjust the overall scene for enhanced blacks while the pause indicator is on the screen. Otherwise the lamp might dim, reducing black levels. My general observations are, that while actually watching the scene, the Optoma H27 does produce blacker blacks than I can capture when paused. Still, it does not match the InFocus, but ends up definitely closer to the InFocus than the W100. With the Epson, you'll note, that there are also less stars visible, however, it is probably the least overexposed of these projectors, but in normal viewing it does not reveal the starfield as well as the others.
Lord of the Rings - Gandalf (DVD)
Epson Home 20
As you can see, each of the four Gandalfs is a little different. Which is best? Tough call, especially if you consider that they are from exposures taken at different times, and not exactly the same. The InFocus appears to have a higher gamma, tending to make Gandalf's face not quite as bright.
For out of the box, performance, I would personally have picked the BenQ W100 as the best in this case. With the settings changes I mentioned for the Optoma, it is probably the best as far as this scene. The InFocus, however looks extremely natural, but doesn't lift the mid-tones, making it look like the scene was shot on a day that was not bright, whereas the other projectors all capture that "sunshine effect" as I like to call it.
Bottom line on all of this, each projector does a very impressive job on all these images, but the Epson comes up very short in the black level/shadow detail area.
The Optoma tends to give the images the best handling of bright scenes in terms of gamma, as noted on Gandalf, and the Boathouse HD scene. The InFocus is superb on blacks and has the most natural flesh tones, out of the box, by a small margin.
This is one reason why I often indicate that many buyer's final selection may well be based on factors other than pure image reproduction. Each of these projectors does a very respectable job in image quality when viewed separately. When images are compared, you see differences. In reality, though none of these projectors could claim to have the best result consistantly across the four test images here, let alone, if I provided more image comparisons.
So start factoring in those other issues - positioning the projector, rainbows, screen doors, pixel visibility, etc.
The next section - General Performance, will go over a few other differences between these four home theater projectors that may affect your final decison.