Optoma HD23 Projector - Performance

Posted on July 16, 2013 by 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.

Optoma HD23 Brightness

Lumen Output and Color Temp at 100 IRE (mid zoom)
Cinema	1081 lumens @ 7773
Bright	C1045 @ 9291, 1176 @ 7892 on Warm color temp, 1319 @7983 with Brightness on default of 50
Photo	1045 @ 9045
Reference	736 @ 8578
User	736 @ 8578

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.

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.)

Color Temp over IRE Range (Cinema mode)
30 IRE	7991K
50 IRE	7991K
80 IRE	7840K
100 IRE	7773K

Here's what Cinema mode looked like as far as color temperature across the brightness spectrum.

or 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)

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.