Optoma HD73 Projector Review - General Performance
Optoma HD73
Image Quality
General Performance
Warranty
Summary, Pros, Cons
Menus
User Memory Settings
Remote Control
Aspect Ratio
Lens Throw and Lens Shift
Ceiling Mounting
Image Shift
SDE and Rainbow Effect
Light Leakage
Audible Noise Levels
Projector Brightness
Lamp Life and Replacement
Projector Screen Recommendations
Calibration
Image Noise
Menus
For the HD73, Optoma sticks with the same basic menu system as the HD72.
There are five modes, Cinema, for best viewing, Bright, when you have ambient light to fight off, TV, which enlarges the image slightly, and apparently affects the overscan, for regular non-HD TV viewing (and VCR's if you still have one). There is also sRGB for color matching (that few ever use), and lastly a User setting for saving your favorite combination of adjustments.
When I reviewed the HD72, I used Component Video as the source. With the HD73, I used HDMI. On the HD72 with component, the Color (saturation) and Tint controls where not accessable (definitely accessable on S-video and composite). On the HD73, they are both accessable on HDMI (and I'll assume DVI). I did not check Component Video to see if they have been added there.
As you can see the main image menu also offers Contrast, Brightness, and Sharpness, and lastly the Advanced Menu. 
On the Advanced Menu you will normally want "Degamma" set to Film for movie watching. Video provides a lower gamma (brighter in the mid-ranges).
Brilliant Color adds zip to the image. I found 3 and 4 to work best, and preferred 4 for most of what I watched. By the time you get up to 8,9 and 10, the image does get really "Brilliant" but unnatural. In Bright mode, Brilliant Color defaults to 10, but, of course can be turned down.
I didn't spend time with True Vivid. When I tried it with the HD72, cranking it up briefly, I didn't like the results, again not very natural I left it at 0 for all my viewing although 1 was ok.
Color Temp should be a 0 for DVDs and movies. 1 works great on HDTV, TV and, in general, sports. The 2 setting is for maximum brightness and is the default for the Bright mode.
Image AI is discussed in the Image Quality section. I almost always ran this on. Since I didn't notice the AI's function of brightening and dimming the lamp to optimize each frame, as visible or annoying under normal watching, and since this produces the best results in terms of apparent contrast, I could find no reason to turn it off. 
If, however you have a smaller screen, you could shut it down and put the projector into Low power mode, to make this projector less bright. The sub- menu for calibrating the projector is the RGB/Gain/Bias menu shown here.
There is also a menu for selecting your source (yes using the remote is easier)!
That takes us to the Display menu (shown below), but everything on it is rarely used, and can be controlled directly from buttons on the remote.
\The Setup menu (no image) handles projection (ceiling, floor, rear screen..) menu language, and display type (16:9 or 16:10).
Lastly the Options menu, with lots of goodies, including where you want the menu to be on the screen, whether you want the projector to seek sources automatically or let you do it manually, a High Altitude option for running the fan at full speed at higher altitudes to keep the projector running cool, and Lamp settings.
The Lamp Settings sub-menu which tells you how many hours, and lets you toggle between Bright lamp mode or Low (if AI is turned off), plus a lamp reset. If ImageAI is engaged, the Lamp brightness choice is grayed out, as it will automatically be in Bright mode, with ImageAI engaged.
The last item on the Options menus is the Reset.
Overall the menu layout is pretty good, and easy to navigate. Text is large enough to easily read even if you are sitting pretty far back.
Optoma HD73 User Memory ettings
Optoma projectors all seem to inherently save settings based on the source. This saves Optoma from having to have 3 or 5 or more, User settings. Essentially, if you have three or four devices feeding the projector, the projector knows which is which and will recall the settings you have selected.
Optoma HD73 Remote Control
The HD73's remote is identical to the HD72's. it's a nice little remote, very well laid out, but has one major flaw, and one item that might bother you.
The flaw is the remote's range. Sitting in my prime theater seat, with 11 feet to the screen, and trying to bounce the remote's signal off the screen (or wall) to the projector that is about 15 feet back, 
I just couldn't get the projector to notice the remote. I had to point the remote behind me at the projector. Of course, if you are going to buy a 3rd party remote to control all your devices, as many do, this becomes a moot point.
Even if I stand just a couple of feett from my screen, I can't get a bounce off of it to the projector. Pointing straight at the projector though, I was able to use the remote out as far as 18 feet (as far away as I could get in my room).
The other point, is that there is no LIGHT button. All the buttons on the remote are backlit, and glow brightly and are well labeled. Pressing any button will turn on the back light, but, hitting some of them will change things. The Enter key is safe however and easy to feel.So the lack of a separate back light button is a non-issue.
Let's look at the buttons:
As you can see, the power is on the top right. Once to power up, twice to power down.
On the next row, brightness and contrast. Once you select one of these, the left and right arrow keys allow you to adjust.
Next is the Digital Image Shift (up and down) buttons. This feature is described below. Right below them are the Horizontal and Vertical Keystone correction buttons (best to avoid, as they degrade the image slightly).
Then comes a nice large set of four arrow keys with the Enter key in the middle.
Immediately below - on the left, a very small menu button, and opposite it, the mode button (Cinema, TV, Bright). Small, but both are easy to feel in the dark, being near those huge arrow key buttons.
There is an overscan control (not covered) to remove edge noise often found on standard TV signals, and a digital zoom button, below the other keys. Then, four aspect ratio buttons, and finally separate buttons for each source (DVI, HDMI, Component, S-video, and Video.) Note there are two buttons for DVI, one for a digital signal, the other for an analog signal (such as your computer.
That about wraps it up. Nice, If only it had more range!
HD73 Aspect Ratio
The HD73 is one of the now many DLP home theater projectors that use DLP chips that have 16:10 ratios, not the 16:9 which is the HDTV standard That gives you 1280x768 instead of the usual 1280x720 resolution. This has a number of implications:
It does mean that you can hook up a computer to your projector and output true XGA resolution, without any image degrading compression technology. (WXGA - "wide XGA" most often means1280x720, and therefore really can't do true XGA (1024x768) without compression. There are a small handful of WXGA projectors that use 1366x768 which can do XGA without compression. The later has only been available on LCD powered projectors. Texas Instruments (TI) has apparently decided that a good compromise is to stick to the 1280 width (same as the HDTV format) but add about 6% more height to the projected area giving them the 1280x768 WXGA). Yes that means there are now three different resolutions that are all called WXGA! (So much for standards).
So, do you buy a 16:10 screen (you can get those made custom), or go with the traditional 16:9 screen. I expect the vast majority will go with 16:9. That means that when you set up your projector to fill the 16:9 area, you will have some overshoot above and below the screen. If you have 100" diagonal screen, the usable surface is just shy of 50" tall. The overshoot at the top and bottom works out to a little more than 1.6 inches at the top and at the bottom. This normally means that the unused area (when watching DVD or movies will throw some dark gray light that will hit the mask around your projection screen. This should be barely detectable assuming your screen has a nice (typical) matte black border around the viewing surface. Note if you are buying a pull down screen (they normally have smaller borders, you might want to make sure it has at least 1.75" of black material at the bottom.
Of course, if you do go this route (a 16:9 screen), and you do project an XGA computer signal, you will have the first 24 pixels hitting the border at the top, and the bottom 24 pixels hitting the bottom border. If your projector is mounted (or placed) where you can access it, you could, of course zoom out just a touch to allow the whole XGA image to fill the screen.
I watched the HD73 on both my Firehawk (128") and the Carada Brilliant White (106"), and never noticed the light on the border, unless I was specifically looking for it.
Like most DLP home theater projectors, there are also some unused pixels on the left and right, so if you are trying to mount your projector exactly at the inner limit defined by the zoom lens, you may have a little space on each side of the screen. Optoma's lens throw info is further down this page.
Of course another big- for some, advantage of the Optoma using the 16:10 aspect ratio, is that this projector will double beautifully as a business projector. I guess that means a lot of people will be writing them off as a business expense.
Optoma HD73 Lens Shift and Lens Throw
To fill a 100" diagonal 16:9 screen, the front of the lens of the HD73 can be placed as close as 11.48 feet, or as far back as 13.81feet. (Based on Optoma provided specs.)
You can find a chart on the HD73 brochure on the Optoma website for seeing what size screen will work from any given distance. There is also a lens throw calculator that I haven't played with.
The HD73 has a lot of lens offset, which is the projector's fixed lens shift. The projector, if ceiling mounted, will have its center of lens, above the top of your screen surface. Conversely, if you place it on a table, the center of lens needs to be below the bottom of the screen surface. The amount of this offset is more than found on most projectors so you may have a problem if you are converting, say, a basement where you only have 7.5 feet tot he ceiling, and a fairly large screen, because the projector will be well above the top of the screen. If you use a flush type mount + the distance to the center of the lens, you will probably still be at least 7-8 inches from the ceiling.
I should note that most projectors with (variable) lens shift, will let you place the projector almost anywhere vertically between the top and bottom of the screen, some will even allow offsets that will allow the projector to go significantly above (or below) the screen surface. Competing LCD projectors usually have lens shift with lots of range. This is one of the weaknesses of DLP projectors in this price range.
DLP projectors like the Optoma HD73 (and HD72, HD70) and the BenQ PE7700, as well as the InFocus IN76 and IN78, Planar 7060, Mitsubishi HD1000U and HC3000, all lack lens shift. The offset can vary a lot. Whereas the Optomas', InFocus'and Mitsubishis' mount well above top of screen, the BenQ, by comparison, has a 0 degree offset, which puts its center of lens even with top of the screen. It's all just a matter of what will work for you, in your room. The Planar falls somewhere inbetween.
According to the manual the lens offset is 6.52 degrees to the top of the image, and that assumes you are using the full 768 vertical pixels, whereas, I believe most people will use a 16:9 screen and only 720 pixels of height. Depending on the zoom setting, for a 100" screen, I measured projecting the 100" diagonal from 13.8 ft - (the greatest distance for that sized screen) the offset was approximately 15.3 inches from center of lens to bottom of the screen. BUT that would be for the 16:10 image. So add an additional 1.6 inches to the bottom of a 720 line image. End result, you are looking at having the center of lens 16.9 inches below (bottom of screen) or 16.9 inches above (top of screen) for a 100" screen at max distance of 13.8 feet. (Please note, these were quick measurements - do not rely on the them for precision.)
A Note Regarding Optoma HD73 Ceiling Mounting
If you are using a 3rd party universal ceiling mount (as most do), this may be helpful: The Optoma uses M3 type metric screws. The maximum length for the screws is 10mm, the minimum is 7.5mm.
Considering The Optoma HD73's Digital Image shift
This is a nice touch that has been on many Optoma home theater projectors and some others (the old NEC HT1100 come to mind). It allows you, if you are projecting less than the full 1280x768 image, to move the live portion of your image up and down.
The best example would be this. You are watching a DVD. You have the usual letter box at the top, and the bottom. With digital lens shift you could move the whole movie image down to the bottom, eliminating the letter box at the bottom (and doubling it at the top). This does not affect the quality of the image!
You can also use this in part, to deal with the 16:10 aspect of the projector, and the large lens offset. You could raise or lower your DVD or HD image (100" diagonal screen) by that 1.6 inches, thus removing 1.6 inches of offset, getting your projector a bit closer to the top or bottom of the screen. That's not much, but might help.
Rainbow Effect and Screen Door Effect
The Optoma HD73 projector is DLP, and as such has a pixel structure that is far less visible than found on most LCD projectors. As a result, for practical purposes, the Screen Door Effect (SDE) is not an issue. If you sit close enough to a large screen to actually pick up the SDE, you are probably sitting so close that the image is too soft to enjoy.
The Optoma is comfortable at about 1.1 times screen width. with a 100" screen, you should have no issue with SDE if you are sitting around 7-8 feet feet back. For those of you who never want to see a pixel structure, even in credits and large stationary white areas, will probably prefer to be more like 1.3x back. Most LCD projectors (which have much more visible projectors would require about 1.4x to 1.5x screen width), as their equivalent to 1.1x on the HD73. The one exception is Panasonic's PT-AX100u, which uses "Smooth Screen" technology, and has less visible pixels, but is also a touch softer than other projectors. (Personally I like the immersion of sitting close. I sit just about 11 feet from my 128" diagonal screen (10 feet 7 inches wide). That puts me between 1x and 1.1x. I can see the pixels in white areas like text credits of movies, but otherwise its not an issue.
In other words, if you like the big image feel, DLP projectors are for you!
DLP projectors rely on a single DLP "chip" and bounce white light against it. Color images are created by timing the light against a spinning color filter wheel that typically have red green and blue segments (and sometimes white). Without getting into the intricacies, some people, due to the color wheel, see flashes of red, green and blue, referred to as the Rainbow Effect. Early DLP projectors (about 10 years ago had 1x (one times) wheels. Today's projectors use faster wheels to reduce/eliminate the effect. Most business projectors use 2x wheels while almost all home theater projectors today use 4x or 5x wheels. (A few older entry level HT projectors still use 2x.) Having faster speed wheels on home theater projectors is due to the rainbow effect being more visible on motion video than still (business type) images.
The Optoma HD73 projector uses a 5X wheel, whereas the HD72 used a 4X color wheel. That basically means that in terms of the Rainbow Effect, the HD73 is as good as any. Few folks can pick up the rainbow effect at all even with a 4X wheel, and less can, with a 5X. Myself, I'm slightly sensitive to the rainbow effect, and do pick it up occasionally (very dark scenes with bright, fast moving objects), with a 4X wheel. I rarely spot it with a 5X wheel, even on those types of scenes. I consider the move to 5X to be an important improvement for some potential buyers.
Problem is, no one seems to know what percentage of the population has an issue with the effect on a 4x projector or a 5x projector. If I had to guess (a wild one), I would say 5x DLP projectors are only an issue for 1-4% of the population, and I don't know if that number increases by 25% or 100% for a 4x color wheel. Pure guesswork.
Let's say that dealers report very, very few returns of DLP home theater projectors due to the effect, but if it bothers you, bingo: Get an LCD projector.
This is the usual tradeoff. Some people see the rainbow effect, and therefore buy LCD, while many people who like to sit closer to their screens for more immersion (the really BIG screen feel), prefer DLP because pixels are less visible (screen door effect). The good news - most buyers are happy with either technology.
In summary, there's a small possibility that you might not notice the rainbow effect with an HD73, but will on some other DLP's like Optoma's HD72 or HD70. I suspect, however, that if you see it on a 4X machine,, you'll probably also see it on the higher speed, but less frequently.
I certainly wouldn't avoid the HD73 because of the rainbow effect unless you already know you are susceptible to it based on viewing other projectors, because very few will notice it. If the HD73 is your first DLP projector though, power it up, feed it a movie and check it out right away (projecting on your wall will be fine), and be aware of your dealers return policy.
Optoma HD73 Light Leakage
The HD73 home theater projector is well designed to prevent light leakage. There is no issue from the vents on the bottom or sides. There is some reflection coming out of the lens that points toward the bottom of the projector, however it is by no means bright. If you are ceiling mounting very close to the ceiling, and your ceiling is white or near white you will be able to look up and see it. It certainly won't be bright enough or evident enough to draw your attention from the screen!
HD73 Audible Noise levels
The projector as noted elsewhere, claims 27db noise levels (low power). Since most will run the projector with AI on, however, the fan will run louder. If I had guess, I would put the noise level at full lamp power (or AI on) around 32 to 33 db. As a result, in full power, the fan would have to be considered on the noisy side. Those demanding a really quiet projector, that they never notice (even on quiet movie scenes) will not find the HD73 acceptable in full power. But, I should point out, that few are that picky. For most the audible noise just "dissapears" much as your hot air heating system, or your refrigerator. You just tune it out.
Optoma HD73 Projector Brightness
When reviewing the older HD72, I was dazzled by the projector's brightness. In best mode (Cinema) it produced 518 lumens with lamp on full power. In part this was helped by using a color filter wheel with a "clear slice" on it, so it could output more white when needed.
The HD73, in changing the color wheel to a 5X and removing the "clear slice", makes the projector more of a "movie purist's" projector. In doing so, however it took away a significant portion of the HD72's impressive brightness. Instead, the HD73 is barely average in brightness.
I was so under awed by the initial measurements that I suspected that the HD73 Optoma sent me, may have been defective. I took the usual measurements, but contacted them for another HD73, which arrived 48 hours after my contacting them. With the first unit I have three measurements to report. The default Cinema mode, lamp on full power produced 304 lumens, however, for movie watching, the Color Temp setting needed tot be switched from default 0 (way too bluish an image), to 1. As it turns out, the first projector was screwed up, and the second HD73 worked best for movie watching with the Color Temp at its default 0 setting. The zoom, I should note was at mid-point, so the projector will be just a touch brighter in full wide angle, and a touch dimmer in full telephoto. Remember, this projector has only a 1.2:1 zoom so the shifts would be only a couple dozen lumens either way.
So, by the time the first unit was in color temp 1, and some minor color adjustments were made, the lumens dropped to 255!
Good news. HD73 number two, with color temp at 0, (and after minor adjustments), managed to crank out a more respectable 332 lumens. This was with the lamp in full power, as was the first unit's measurement. Compared to the Optoma HD72, that's a drop in brightness of 36%. From a practical standpoint, that would mean a 124" diagonal screen for the HD72, would be as bright as the HD73 on a 100" screen!
The Bad news: Even the significantly brighter second projector is ranks among the least bright available.
Since I mentioned we did the measurements in Full Power mode (most will need it), you must be curious. Low power mode dropped the brightness down just over 21%, for a measurement of 261 lumens, on HD73 number 2.
As I said, not a particularly bright projector. With lamp on full power, AI engaged, the projector, really struggled trying to fill my 128" Firehawk, and that with a brand new lamp. After watching the projector in that mode, I finally settled on a much smaller image size - about 105" as a good large size for the HD73. I could have pushed it a bit more, but keep in mind, lamps dim over time. With a screen like the Firehawk, 110" is probably pushing it. The projector seemed more comfortable in my testing room on the Carada Brilliant White (a matte white surface with an approximate gain of 1.3). The Optoma easily filled it's 106" diagonal, and with a screen like that or similar, 110" is reasonable.
Of course the HD73 has Bright and TV modes (as well as Photo which replaces sRGB on the HD72), and User.
Bright Mode is for when you need to do battle with ambient light. With the Color Temp set to Bright's default of 2, the image is too cool (bluish) around 9500K, yet the first (defective) HD73 only cranked out 483 lumens. The second projector, however, managed 558 lumens. That's almost exactly half of what Optoma claims. Changing the color temp to 1, more ideal for TV/HDTV viewing, dramatically dropped the lumens, so let's say that Bright - is for when you need every last ounce of brightness.
TV mode, defaults to color temp of 1, and offers an excellent color temp for white (100IRE), of 7676K - very, very good for TV/HDTV/sports, brightness however, was not significantly brighter than Cinema mode, with only 383 lumens on the "good" HD73.
So, what we have here is a spectacularly overrated projector in terms of lumens. Optoma claims 1100 lumens, and, even it Bright, achieved just half of that. Fooling around, boosting green, etc. I could muster up just over 600 lumens, but, as they say - "that's nothing worth writing home about".
To put this all in perspective, here are some numbers from the competition:
Panasonic PT-AX100U: Best mode (Cinema1): 707 lumens, Brightest mode (Dynamic): 2025
Sanyo PLV-Z5: Best mode (Pure Cinema): 262/304 lumens (depending on iris setting, but there is also Creative Cinema 369/479 lumens), Brightest: Dynamic 963 lumens
Mitsubishi HC3000: (which has excellent black level performance): 465 lumens best mode
So, as you can see, only the Sanyo is less bright in "best" mode, and not by much. On the other hand, the Sanyo and all others, are signficantly brighter in brightest mode - by almost 60%!
Projector Lamp life
Optoma claims 3000 hours for their lamp (in Low Power mode), 2000 in Bright mode. Optoma tells me that with AI turned on, actual lamp life will fall between those two numbers). Most users will run the projector with AI on, which means the lamp will brighten and dim as needed. I could guess at 2200 to 2500 hours, but no way to tell.
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Optoma HD73 Projector Screen Recommendations
This continues the points I was making above. Important to consider is that the HD73 has much improved black levels compared to the brighter HD72. Overall, if you are going more than 100" diagonal, a screen like the Carada, Stewart Studiotek 130, Da-lite CinemaVision, etc., is a good match, and you still get very good black levels. If you really are going for blackest blacks, though, the Firehawk or its equivalents (not that anything is quite like a Firehawk), like the Da-lite HC Da-Mat, or the Elite HC Gray, would be good choices, but keep the screen size a bit smaller. Dark walls are a real plus, in the hunt for blackest blacks. My personal opinion, is that you can go a larger screen size if you have really dark walls, (and ideally, a dark ceiling and floors too).
While I did watch movies successfully at about 105" diagonal on the Firehawk, that is probably a little too large a surface for those really expecting to get 2000 hours before replacing their lamp. For the Firehawk, think 100" diagonal as a maximum
Bottom line: The HD73 is a projector for fully darkened rooms. It simply lacks the horsepower for large screens. 110" in the right room, with a screen with 1.3 or 1.4 gain is about the maximum. The projector will work best with 92" and 100" screens. If you also want to watch some football with some lights on, this is not the projector for you.
BTW, with that roughly 105" size image projected on the Firehawk, I also tryed out my PS3 on one of the auto racing games, and with mode set to Bright, it worked out just fine with very low room lighting.
Calibration
Interestingly, the first HD73 with color temp at 1 (Cinema mode), performed almost identically to the second HD73 with color temp at 0. Below are the numbers for Cinema mode, color temp 0, on the HD73 #2:
The numbers are after minor adjustments to slightly lower the color temp, and to increase green's slightly.
100IRE (white): 6619
80IRE: 6698K
50IRE: 6735K
30IRE: 6570K
(The goal is to have all levels of gray/white at 6500K)
This was accomplished by changing the Advanced RGB settings to:
Bias: Red=0, Green=0, Blue=1 (those are the same as the color temp 1 default)
Gain: Red=-10 (instead of -11), Green=-10 (instead of -11), Blue -11 (default)
The Optoma's Contrast and Brightness settings were essentially dead on, +/- 1 of the defaults.
Image Noise
Last topic. If you look closely into the dark areas of an image, you will find some noise. This is typical of DLP projectors as compared to LCD models. The noise levels on the HD73 are very typical of DLP projectors, and I have not found the noise to be an issue. Running the Silicon Optix HQV test disk, the HD73 performed very well overall, with passing grades on all noise and jaggie tests.
That raps up this section. As you have read, there are some issues, mostly ergonomic ones, with the HD72. If none of them is a problem for your particular installation, the HD72 should be at or near the top of your short list.
Optoma HD73
Image Quality
General Performance
Warranty
Summary, Pros, Cons