Optoma HD23 Projector - Performance
12/2/12 - Art Feierman
In this section, we consider the brightness (including full measurements), sharpness, and other issues including image, light leakage, and audible noise of Optoma's HD23 home projector.
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Optoma HD23 Brightness
The HD23 is a brighter than average home projector, although not by much. That's despite the published spec of 2500 lumens.
If you like to judge a projector based on how well the product meets the manufacturer's claims for brightness, then we have here an Optoma that doesn't come close.
But what matters is the projector's actual abilities.
I'll try to forget that this projector comes up shorter, compared to claims, than any other low cost projector, (even the Optoma HD33 we reviewed earlier this year) which was also well below claim.
Setting that aside, what we have here is a reasonably bright projector.
Time to consider the Optoma HD23 projector's measurements:
Lumen Output and Color Temp at 100 IRE (mid zoom):
Cinema = 1081 lumens @ 7773
Bright = 1045 @ 9291, 1176 @ 7892 on Warm color temp, 1319 @7983 with Brightness on default of 50
Photo = 1045 @ 9045
Reference = 736 @ 8578
User = 736 @ 8578
We are using Cinema as our "brightest" mode, and interestingly, after Mike tweaks (quick-cal) the settings for a better picture, Cinema mode gets brighter, not dimmer (dimmer is typical)!
Those numbers above, lumens and color temperatures, are all "right out of the box", without any adjustments to settings like contrast or brightness, which can affect overall brightness.
Now don't let this freak you out. As I just said, our "Brightest" mode turns out to be Cinema! Our best mode is based on the default User, and is dramatically less bright than Cinema, but still a good deal brighter than average. (On most projectors modes with names like Cinema or Theater tend to be the "best" mode, or at least one of the better lower brightness modes.)
Here's what Cinema mode looked like as far as color temperature across the brightness spectrum:
Color Temp over IRE Range (Cinema mode):
30 IRE = 7991K
50 IRE = 8078K
80 IRE = 7840K
100 IRE = 7773K
For some reason, Mike didn't give me the equivalent IRE measurements for User mode, but that's OK, afterall, a little further down, you'll have our post calibration numbers, and of course we tell you how to set the HD23 projector to achieve those.
Back to the default Cinema mode. It's definitely on the cool side, but not terribly so. And, per Mike, an easy calibration to improve.
Mike noted this: No QuickCal of Bright mode was necessary, because the calibrated (Cinema) mode was higher than the Bright mode with default color temp and the calibrated Cinema mode was only 59 lumens less than Bright mode on Warm color temp. Considering our calibrated User mode looks a lot better than Bright mode, no one will care about 59 lumens (give or take).
So, what are the final brightness numbers?
Post Calibration: User "best" mode = 713 lumens
Post Calibration: Cinema "brightest" mode = 1117 lumens
As it turns out both Cinema, and the User mode calibrate very well, Mike immediately pointed out that skin tones look better in User mode. There is a Bright mode, but Cinema is virtually as bright and a better choice, so Mike chose Cinema as the best "brightest" mode. You'll notice below, that the User mode has a tighter range of color temp across the brightness range from 20 to 100 IRE, which no doubt explains the better skin tones.
Measurements for both modes post calibration found below.
Lumen Output (Standard Lamp (eco), Bright mode): 832
It should be mentioned that Standard is Optoma's low power lamp mode - many projectors call that eco-mode. Optoma calls their full lamp power Bright, so when the projector is at its brightest, it's actually Bright (color mode) and Bright (lamp mode). That should confuse everyone, at least for a few seconds.
That represents a drop of just over 20% of the HD23 projector's brightness, . Expect that same amount of drop in any mode when switching from bright lamp to standard lamp.
There is also an Image AI lamp setting. In this mode, Optoma lowers lamp brightness dynamically to reduce black levels (and the bright ones too), similar to a dynamic iris.
Image AI's action, as we have reported with some other previous Optoma projectors, is noticeable. It tends to snap on or off, a second or so after a major scene change in brightness.
I'd recommend leaving ImageAI off. Why? I expect you'll notice it's snap dropping and brightening, to be more distracting than any benefit it offers in terms of blacks.
Effect of zoom on lumen output (Bright mode):
Zoom out: 1129
Mid-zoom: 1045
Zoom in: 940
No surprises above. With a 1.2:1 zoom we don't a dramatic drop in brightness between wide and tele, and as you can see, the variation is only about 17%. On projectors with 2:1 type zooms, the drop can be as much as 40%. Of course, the trade-off is placement flexibility.
Mike calibrated the User mode, and came up with the results below.
HD23 Color Temp over IRE Range (Post calibration):
Cinema User
20 IRE 6324 6540
30 IRE 6427 6552
40 IRE 6466 6501
50 IRE 6621 6508
60 IRE 6702 6516
70 IRE 6642 6540
80 IRE 6448 6474
90 IRE 6477 6492
100 IRE 6500 6387
Average gamma= 2.24
Wow, except for white (100 IRE), the entire range in User mode is within 80K!!! Even with white, it's only 165K. That's about as good as it gets.
Comparing Image Modes:
Below, the same Victoria Secret model, with each image taken with the same exposure. Thus you see the differences in both brightness and color. Since there isn't a huge difference in brightness, the User mode's not too dark, and the brighest modes are only a touch overexposed.
Our Best mode first - Calibrated User:
Cinema mode - Our "Brightest" mode, also post calibration:
Below: Bright mode - pretty good for what measures the brightest on this projector (by 59 lumens), but still not as good as User (and Cinema)
Photo mode is a bit more contrasty than the other modes, not surprising. If you really are looking at photos, I'd say compare vs. User. This is punchier, but User will be more natural.
Reference mode is identical to an unadjusted User mode. So, essentially provides the same results. Since this is not adjusted, consider this how User would look before Mike's calibration:
Truth is, not a bad looking mode in the lot. In other words, this is a good "take it out of the box and enjoy" projector. Our recommendations will make some minor improvements that some of you will appreciate, but nothing earth shattering. Try Mike's results (calibration page), you just might like the improvements.
Optoma HD23 Sharpness
You get about what you should expect. A pretty sharp, low cost DLP projector. With only a single chip, not 3 panels like 3LCD and LCoS projectors, there's no misconvergence to cause softness. That said, the HD23 doesn't seem to have the best optics around, and considering the price, that's fair.
That said, consider the HD23 projector to look at least as sharp as any of the slightly more expensive 3LCD projectors near its price, and it is certainly comparable to other projectors under $1000. That's not to say that it's the sharpest. For example we typically find BenQ's competing projectors to be a touch sharper. We're about to review the direct BenQ competition, the new W1070, so check out that review if you want to compare these sharpness images, when that review publishes mid-December.
Top left: Optoma HD23, Top Center - Optoma HD33, Top Right - Mitsubishi HC4000.
2nd row left: Epson Home Cinema 3020, center: Viewsonic Pro8200, Right: Acer H9500BD
Here are a few test patterns for observing the HD23 projector's handling of fine lines, small text, and more:
Optoma HD23: Bottom Line Sharpness
I've got no issues with the Optoma HD23's sharpness. I'm pretty sure it's not the best in the price range, but "close enough." The image looks crisp, without the slight misconvergence found on LCD projectors
Light Leakage
Tsk, Tsk! The front grill of the projector leaks a fair amount of light for a home projector. It's mostly off to the front right. In a really dark room, with a dark scene, you can spot it. For the typical use of this projector, I don't see it as anything to be concerned about.
After additional consideration, I have to admit the light leak lights up the front of the projector in a colorful (reds orange and white), and impressive way. Gives the projector some real character.
Image Noise
I'd say the HD23 has typical DLP levels of mosquito noise - your basic background noise. And that seems to be a touch more than projectors using the other technologies. We've been living with this since the start of home theater projectors.
The tendency of a bit more background noise hasn't dampened the enthuisasm for DLP projectors in general. Video panning is pretty good. In general Optoma projectors do very well on the Silicon Optix test disc.
Audible Noise
It's definitely not quiet at full power. Small single chip DLP projectors tend to be a bit noisy. At full power, the Optoma HD23 has to be considered one of the noisier around. Part of the trade-off is the HD23 projector's very small size. Larger projectors have more room to baffle the sound. In other words, this HD23 is fairly typical for projectors in this price range, even if there are dramatically quieter projectors at 3 times the price. Perhaps we should say that audible noise is one of the things (not the key difference) that separates home theater projectors from home entertainment projectors.
I observed that there was a whine that varied in intensity, and at times, rose to be heard above the fan noise. Even so, if you're watching sports, or most TV, you probably won't notice unless you are sitting real close. It's no louder than my PS3 when it feels it needs to cool down.
The good news: Drop lamp to low setting and the projector is reasonably quiet. The pitch is low and you have to get close and listen to hear any whine. Back to my PS3, vs. my PS3. When you are in Standard (low power) on the HD23, and that same PS3 kicks it's fan up, the PS3 easily drowns out the HD23, even though the PS3's 10 feet from my seat, and the HD23 is less than 4.
In other words, don't sweat it. For most viewing, you should find high power to be fine. If you are watching the kind of soft spoken movie with lots of very quiet scenes, and you notice the projector, try low power!