Optoma H78DC3 DLP Video Projector

by | Dec 7, 2005 | Component Reviews | 0 comments

Optoma H78DC3 DLP Video Projector
$3,999 SRP

Optoma Technology, Inc.
715 Sycamore Drive
Milpitas, CA 95035
408-383-3700 (voice)
408-383-3702 (fax)



Basic Description

Single chip DLP video projector utilizing HD2+ TI chip (1280×720 16×9) with Dark Chip 3 technology; 8 segment color wheel; 16.7 billion colors; remote control; 250 Watt lamp with 2000/2750 hour lamp life; 800 ANSI lumens; 4000:1 (rated) contrast ratio; multi-system compatible (PAL, SECAM, NTSC); accepts 720p, 1080i, 480i/p, 576i/p; vertical and horizontal keystone correction; throw ratio 1.6-2.16:1 (distance/width); user adjustable picture (not aspect ratio) controls for each source; vertical and horizontal lens shift; integrated lens cap; adjustable feet; electronic optical zoom and focus; automatic source selection; RS-232 (for control); Inputs: component (on RCA), component/RGBHV (on BNC), s-video (on DIN), composite video (on RCA), DVI-I w/ HDMI adapter; IEC standard power cord; (2x) 12V triggers; front, rear, desk or ceiling projection; 16.9” W x 5.3” H x 12.0” D; 16.5 pounds; 2-year warranty on projector; 90 days on lamp.

Associated Equipment

HTPC, Stewart 135” 1.33:1 Screen with Studiotek 130 material, Revelation cabling; Denon DVD-3910 DVD player, Stewart Luxus 100” 1.78:1 Screen with Studiotek 130 material, Audioquest and Accell cabling.


Projection Offset.
  The beauty of digital projectors in comparison to CRT/analog projectors is the ease of set up.  I set the projector on the floor and aimed it towards the front of the room.  The projector can be set for rear/front and ceiling/floor mounting.  The projector has very little vertical offset.  The manual claims it has electronic vertical lens shift, but in fact, there is a manual knob on the top of the projector.  I was able to get the image to move down, but not up; therefore, the bottom of the image was almost equal to the height of the lens from the floor.  I moved it on a table and did my viewing from this position.  The projector comes with an integrated lens cap.

Warm-up and Focus. 
I first connected my Home Theater Computer via the RGBH/V input and an image popped up within 70 seconds.  It took about 90 seconds for full warm-up.  The projector will automatically check for an active source, but this can be disabled by selecting the source lock feature in the menu.  However, it would re-lock to a signal with the Denon player every time a disc was ejected, started, or when a source is shut off.  The computer was set to produce an image with 1280 x 720 resolution (a.k.a. 720P).  I thought the image looked a little soft, but changing from 16×9 to native (in the format adjustment) improved the clarity.  Necessary distance can be calculated based on the throw ratios in the Description section.  With the 135” 1.33:1 screen I was able to get a slightly smaller image than a 123” 1.78:1 screen size.  The zoom feature worked smoothly and focusing is aided by a small box with the word “focus” in the center—both are done electronically.  The power button on the side is a bright blue light that cannot be turned off.  You may want to cover it with black tape.

Pixel Structure. 
At 12’ away the pixel structure was indiscernible on a full white screen image.  On the opening credits of Jackie Brown the DVD pixel structure disappeared at about 14’ away.  This projector performed a good deal better in this regard than models that utilize a 1024 x 576 chipset.  Writing and large areas with light colors made pixels more noticeable, though from the viewing distance above, it was not an issue.  Defocusing the projector could help for closer viewing, but the projector was not razor sharp to begin with.

Mounting and Positioning. 
With projectors being as popular as they are these days it should be no trouble to find a good ceiling mount—many are universal.  Optoma sells one on their website for $299.  The feet on the projector allow angling or tilting the projector as necessary.


Keystone Correction. 
Keystone correction alters the picture in the shape of a trapezoid in order to correct for improper mechanical setup.  In the old days it seemed that keystone correction always mangled the projected image.  As digital processing has improved, so has keystone correction.  The Optoma not only offers a way to correct the image vertically, but horizontally as well.  I used several scenes from Hostage and tried the most extreme settings (+/-50 in each direction).  Since the correction is done on a fixed chip, you lose resolution by doing this, and you can see the trapezoidal shape on the chip if the contrast or brightness is turned up.  However, I have to admit, any difference that it made to the image was relatively minor.  It would be an acceptable solution for situations where the projector could not be set up optimally.

Remote Control.
  The remote control that operates the unit works all the essential functions and allows easy access the menus.  The menu layout is very simple to grasp and does not offer too many levels that might cause confusion.  The remote is backlit and fades away within 10 seconds or so.  There is direct access for the five inputs, a re-sync button that will quickly readjust an input, a freeze button, a hide image function, direct access to keystone, focus, and zoom, brightness, contrast, hue, zoom, and format button to change aspect ratio.  It does not have a sharpness control on it.  The settings in the projector are either named or numerical, so there is no guesswork getting back to a particular setting.  The range of the remote is not super.  From the back it worked fine, but any effort to bounce the signal off the screen did not work well.  From the front it worked okay, but not great.  The writing on most of the buttons is quite tiny, however when lit, they could be seen.  The reverse problem is present on the projector.  The writing is on the casing and not on the buttons, so even though the buttons light, you can’t read what they do.  It would be a good idea to run an IR/RS-232 cable for control.

Picture Adjustments. 
There are three presets named Cinema, Normal, and Vivid.  Within these modes there are the typical adjustments: contrast, brightness, color (video only), hue (video only), sharpness, and gamma.  There are three image mode settings: film, video, and TV.  I didn’t have any measurement equipment to determine the best mode, but I’d read that the TV mode with a “1” gamma setting was an accurate setting.  There is a white peaking control to extend the brightness of whites on the DMD chip.  The manual recommends a minimal setting to achieve the most natural looking image with this control.  Color temperature has three settings.  The middle setting looked about right.  The lower setting looked a bit too warm and the top setting was clearly too blue.  There are 6 adjustments (called contrast and brightness for red, green, and blue) in the advanced section of the menu.  I assume these are the typical gain and cutoff adjustments.  Unfortunately, I didn’t have a color analyzer handy, so I didn’t want to monkey around with the color temperature.  I did note that it seemed to look good on a few test patterns I had with color bars and with gray scale.

Aspect Ratio and Sizing.
  There are four different aspect ratio modes.  I was troubled to discover the projector did not keep the last setting on a different input.  This meant if I were using the Native mode with the computer then when I switched to 16 x 9  to watch DVDs, I’d have to switch it again when I went back to the computer—not very smart!  The Native mode bypasses the internal scaler and doesn’t resize the image.  Feeding the projector images larger than the chip size resulted in the correct size in this mode (i.e. 1080i).  The 16 x 9  mode is designed to be used with material that is widescreen enhanced.  This is the operation mode that I used with DVD.  The Windowed mode is for full frame material like normal satellite and cable, videotape, etc.  The image is inset in the center of the 16:9 frame produced by the projector.  Letterbox will take non-widescreen enhanced material that may be in widescreen shape and zoom it to fit the projector’s frame.  Images on satellite channels that were widescreen or non-widescreen enhanced DVDs worked with this mode.

Miscellaneous Adjustments.
  There is an option to select colorspace (RGB/YUV) or let the projector automatically select it.  You can choose a blue or black blanking color, turn the bright mode on (boosts light output, but reduces lamp life), activate an auto shutdown feature that will turn off the projector after no signal is present, and even operate a digital zoom that will zoom the picture in from the center.

The manual is 31 pages long, but covers just about everything—although not in tremendous detail.  The controls have descriptions for what they do, but not necessarily why or how to use them.  It would have been nice if some of the controls were explained in more detail.  There are diagrams or snapshots of all the adjustment screens to aid the reader.  There are complete instructions for changing the lamp, troubleshooting guides, hookup diagrams, and a ceiling mount diagram.  At first it looks like a pocket novel, but that is only because it offers seven languages.

Viewing I – DVD

With the Denon DVD player I experimented with a few hookup options.  The Denon offers both DVI and component output.  The Optoma comes with an adapter that converts HDMI to DVI for those who would like to use this output from their player.  I located the DVD player next to the projector and used cables less than five feet in length.  The DVI output can work at 480p/720p/1080i.  With Dirty Harry  I tried all three resolutions.  It was clear that the 720p and 1080i settings were an improvement over the 480p setting.  The 720p was not as detailed or colorful as the 1080i setting.  There might have been a greater solidity to the 720p setting, but both a friend and I preferred the 1080i setting.  The component output on this player performed at a much lower level–the image was washed out by comparison.  Even after adjusting the amount of color to the image, it did not come close in clarity, color saturation and purity, or in detail to the DVI connection from this player.  The DVI output worked with the Native setting on the projector, while the component used the 16 x 9 setting.

When I switched to Ghost World the picture improved (due to the better quality of the transfer itself), but the component output did not match that the picture of the DVI.  I had some questions about the image due to the inability to get the eight boxes (contrast screen) to display with the THX Optimizer from Toy Story.  Later I checked the picture with an older Toshiba SD-3800.  I didn’t have this problem using Akira from the Toshiba nor from the computer.  In any case, the Denon and H78DC3 only looked best when using the digital video input on the projector.  I had planned to recommend an external scaler for anyone serious about getting a good image with non-HD sources, but later testing with even a cheap player proved that the component input was quite serviceable.

I viewed a couple more films including Memento Special Edition.  Unfortunately, I’m fairly susceptible to the rainbows that are associated with DLP projection devices.  I had noticed them occasionally during the month or so I had been using the projector, but for the most part they weren’t bothersome.  Black and white material is usually the worst, but with this DVD the rainbows were not nearly as bad as with other projectors I’ve viewed.

Viewing II – DVD/HD from HTPC

Bring It On was up next in the tray.  I tried it both on the Toshiba DVD and on the HTPC.  I thought the HTPC had a slight edge, but it was pretty close.  All in all, the image was very good.  It wasn’t in the league of the high-end projectors of today, but clearly surpasses what you would get 3 years ago for four times the money.  Currently I’d think that it would give any comparable priced projector steep competition.  Even in darker, night scenes the detail was preserved both in lit and low light areas.

High definition clips from Scooby Doo, The Fifth Element, Dodgeball, Charlie’s Angels II, The Day After Tomorrow, and a few clips from HDNET looked gorgeous.  As many times as I’ve seen HD it’s still impressive each and every time.  Even though the images were not presented at the full resolution HD offers, it was nonetheless an impressive showing.  There is no doubt to the improvements wrought with this material versus that of DVD or otherwise.

With very dark films like The Others, limitations of the projector in the area of shadow detail became apparent.  In very low light scenes the blacks were but a very dark shade of gray and it was hard to make out details.  When there was more contrast in the image, it was not a very noticeable effect.

All in all, the image was quite good considering the price of the unit.  For me, the lack of constantly visible colored rainbows makes this projector much more appealing than many others in the same price range and even some more expensive models from other brands.


The strengths offered by the Optoma H78DC3 include: extremely quiet operation, horizontal and vertical keystone correction, the best Texas Instrument DLP chipset (exluding the newest 1080 chips), very good black level and contrast, very low visibility of the rainbow effect, solid video processing, electronic zoom and focus, and a 2-year warranty on the projector.

The inability to save the last chosen format per input is a mild annoyance, but overall operation is smooth and the adjustments on the unit make sense.  It would be nice if the color temperature settings were numerical, so the consumer could have a good idea of what the best setting would be for their use.  The only caution I have is regarding the sharpness and detail of the image.  On most material it was very good, yet the projector lacks the last bit of detail I’ve come to hope for after viewing >$10,000 projectors.  I don’t know if it is a difference in video circuitry, the light engine, or it may likely be the optics, but that is an area where there is still room for improvement with the H78DC3.  Given the price however, it is largely forgivable.  You’ll be hard-pressed to find another projector that will best it in key areas.  If the Optoma is in your price range, it is surely worth a serious look.

— Brian Bloom           big_brian_b@hotmail.com

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