Showing posts with label Useful. Show all posts
Showing posts with label Useful. Show all posts

Tuesday, March 27, 2012

HDTV Expert - Useful Gadgets: Mitsubishi HC7800 3D DLP Home Theater Projector Pete Putman

Shopped for a home theater projector lately? With all of the attention that new, low-cost LCD and plasma displays are getting, it might be easy to write off the home theater projector market’s future.

Yet, front projection is still the cheapest way to get a big image – for the immediate future, at least. And there are some really good deals out there to be found, particularly in multi-function (2D / 3D) projectors.

Mitsubishi has been turning out some really impressive and affordable home theater projectors for the past six years, starting with the ground-breaking HC5000 and continuing with the high-end 3D HC9000. At last year’s Cedia Expo, the HC7800 made its debut, and I finally got ahold of one to play with. I wasn’t disappointed.

Figure 1. Mitsubishi's HC7800 shares a lot in common with the HC9000 3D projector.

OUT OF THE BOX

The HC7800 resembles its bigger brother HC9000 in more than one way. The cabinet has that same high-gloss black finish with an aerodynamic appearance, and a silvery-gray trim around the top panel controls, as well as around the front of the lens, which is offset slightly to the left of center.

Directly behind the lens is a pop-up cover that reveals a knob adjustment for vertical lens offset. As it comes from the factory, the lens offset is pretty high, putting the bottom of the image at the optical centerline. The theory behind this decision is that the projector would most likely be ceiling mounted. However, you can dial the image down quite a bit, although you may see some degradation of brightness uniformity at the extremes.

Figure 2. The vertical lens offset knob is hidden behind this door.

 

Figure 3. Here's the connector line-up for the HC7800.

The standard connector complement includes a single component video input, a 15-pin VGA connector for computers, and a pair of HDMI v1.4a jacks, compatible with frame-packed 3D program formats. Mits has also included an RS-232 port and Ethernet jack for remote control, a pair of 12V triggers for electric screens and anamorphic lens adapters, and a DIN connector that drives the infrared 3D sync emitter.

The supplied remote control should be familiar to Mitsubishi projector users – it’s been standard for several years and provides direct access to inputs, three picture memories, and a bunch of useful tools including color management, frame rate conversion, three iris settings, and the usual brightness / contrast / sharpness / color settings. Brilliant Color mode is also supported.

Figure 4. Same old remote, but some new buttons!

INSIDE THE CHASSIS

The HC7800 is a single-chip DLP design that uses the latest .65” 1920×1080 DMD imager harnessed to a six-segment color wheel. You may be surprised to see mechanical lens offset married to a single chip DLP light engine, but it has become easier to achieve and essentially de rigueur for home theater projectors – especially when the preferred imaging systems make extensive use of lens shift.

The illumination system revolves around a 240 watt short-arc lamp that can be throttled back to 190 watts in low power mode. In theory, this should provide a pretty bright image – Mitsubishi’s spec for full-throttle operation with no image correction is 1500 lumens – but in practice, you’ll see a much dimmer image after calibration, and may require a gain screen to watch 3D content as a result.

Like other Mits projectors, the HC7800 is equipped with an irising system. It should provide an almost infinite black when activated, but also does some screwy things to gamma performance. My preference is to leave it off and use a low-gain screen to take care of low gray levels. However, that approach doesn’t work so well with 3D content as you will see shortly.

MENUS AND ADJUSTMENTS

Menu adjustments abound. Mits provides three User presets to store your settings, and you can tweak everything from brightness and contrast to color temperature (six presets plus RGB high and low), gamma (five settings from 2.0 to 2.4 and 3D, plus two user-defined gamma menus), and five picture modes including ISD Day and Night.

The frame rate conversion menu works on multiples of 24 Hz, so when switched off, you are viewing movies at 96 Hz. Want to clean up all the judder and blurred motion while (and I quote) “…retaining the clicking sensation unique to film?” Select True Film mode. There’s also a True Video mode for 30 Hz / 60 Hz content that ups the rate to 120Hz.

Mits has also given you five steps of motion interpolation to minimize 24 Hz blur and make film look more like video. Play with it; you’ll probably find a setting you like. And all of this stuff also works with 3D movies and video, too.

The iris mentioned earlier has four speed settings, plus OFF. That last one is my preference! As I said earlier, variable iris settings can dive deeper into black than James Cameron in the Marianas Trench, but the display gamma is subsequently compromised and inconsistent. Better to use a lower-gain screen and stick with a fixed gamma curve to get the best results.

The HDMI inputs can also be configured for different color modes and black levels settings. In RGB mode, black will be deeper than in video mode, and whatever HDMI output mode your DVD or Blu-ray player is set to should be matched on the HC7800. In theory, the projector should make this adjustment on its own, based on the signal detected from the player. You can also change video setup for every input on the projector, again with black at 0, 3.5, or 7.5 IRE.

The color management tools are intriguing and should only be used with some sort of colorimeter to either read out the x,y coordinates for each color adjustment, or a graphical display of where the red, green, blue, cyan, magenta, and yellow wind up as you change saturation and hue. Don’t try this adjustment unless you can measure the results accurately!

The HC7800 also has a color space adjustment. In Wide mode, the full gamut of the projector is used, regardless of the signal source. In Normal, the color gamut is truncated and closer to that of the Adobe sRGB color space (also closer to ITU REC.709 HDTV). Between this setting and the color management tools, you’ll get well within the ballpark.

Figures 5a-b: The HC7800's 'full' color gamut is so wide...

...that it covers most of the DCI P3 digital cinema color space.

There are so many aspect ratios supported by the HC7800 that I can’t even list them. The owner’s manual shows 38 different possibilities, including anamorphic (two settings), 4:3, 16:9, two zoom modes, and a stretch mode. Leave this control set to Auto and it will generally figure things out on its own! The dual anamorphic modes are used with an accessory lens, with Mode 1 for video playback and mode 2 for sync with computers.

Yep, I almost forgot – this is a 3D projector, too. The HC7800 is compatible with all 3D formats, with frame-packing detected automatically. However, for side-by-side and top + bottom frame-compatible 3D viewing, you’ll have to change the 3D menu setting manually as there is no way for the projector to know what kind of frame it is showing.

The 3D menu lets you reverse the sync on the 3D glasses if the images aren’t rendering correctly. I’ve never had this happen to me, but it’s nice to know you can reverse the problem. There is also a 2D-to-3D processor which results in ‘fake’ 3D imagery by interpolating relative distances of objects in a scene and creating parallax information on the fly. I have never felt any need to watch 2D content in 3D, but I can tell you that the process works – sort of. Stick to native 3D content and you’ll be happier with the results.

The 3D IR emitter is a compact little gadget with a swivel base that you can mount near the projector, or on top of it. The supplied 3D sync cable isn’t very long, and a super-long 3D sync cable like the one supplied with the HC9000 wasn’t included. But this emitter supposedly has a line-of-sight range of about 30 feet.

ON THE TEST BENCH

One thing I like about the Mitsubishi home theater projectors is that they come from the factory requiring little in the way of calibration. The HC7800 was no exception; all I had to do was switch to a deeper gamma setting for Blu-ray discs and fiddle a little bit with RGB contrast and gain.

Brightness after calibration was measured at 388 ANSI lumens in Low lamp mode, jumping to 466 ANSI lumens in High (normal?) lamp mode. That is a lot lower than 1500 lumens, but in general, you’ll see at least a 50% reduction in brightness when calibrating a projector, and maybe more if you use a steep gamma. With the lights off and my Da-Lite Affinity 92” screen, I was quite satisfied with the results.

Brightness uniformity is a challenge for DLP projectors and the HC7800 measured about 80% to the average corner, with the worst corner coming in at around 55%. Color temperature uniformity was within 515 degrees across the screen – not quite as ‘tight’ as I’d like to see, but for a $3,000 projector, better than average.

Contrast numbers were pretty good, but reveal why Mitsubishi wanted to use an irising system. Using a sixteen-square checkerboard, I calculated ANSI (average) contrast at 477:1 and peak (highest/lowest) contrast at 772:1 – nothing to sneeze at! Sequential white/black contrast registered 1048:1, while a 50/50 white/black test pattern yielded a figure of 663:1.

Figure 6a. Here's the gamma curve for 2.4 Cinema mode. Sweet!

Figure 6b. And here's the gamma curve in 3D mode - consistent, but shallow.

The HC7800’s gamma curves are seen in figures 6a and 6b. 6a shows the final gamma for 2D mode with a 2.4 curve selected, while 6b shows the projector after being switched into 3D mode. Many 3D TVs I’ve tested do very strange things to gamma performance when running in 3D mode, and that’s because the brightness and contrast are pumped up to overcome light lost in the glasses.

Fortunately, the HC7800 is a bit more disciplined and doesn’t jump too far off the tracks, resulting in a 1.94 gamma when showing 3D content. That’s not as steep as I’d like, but at least the curve doesn’t clip or flat-top at the high end, and the grayscale ramp out of black looks a lot like the 2D 2.4 gamma when you are wearing active shutter glasses.

After trying to match up the projector’s color gamut to the REC.709 color space, I came up with the plot shown in figure 7. The user controls can get you very close with red and blue, but the green hue adjustment either wasn’t working or doesn’t have enough range – I couldn’t add enough yellow to the mix to line up with the desired 709 locus. But it was close.

Figure 76. I got oh-so-close to matching the REC.709 color space. Oh well, still an improvement...

IMAGE QUALITY TESTS

For my viewing tests, I cued up 2D and 3D versions of How to Train Your Dragon, one of the better 3D movies I’ve seen. And of course, I pulled out my 3D copy of Avatar to see how it showed. For screens, I used the Affinity for both 2D and 3D viewing, and for some extra ‘punch’ set up a Vutec Silver Star 6.0 gain screen to help overcome the losses in the 3D glasses.

As a 2D projector, the HC7800 is a peach. I’m not a big fan of DLP for the home, preferring full-time RGB imaging found in 3LCD and LCoS projectors. But this box performed much better than I expected, and in fact comes close to the performance of the discontinued $12K Samsung SP-A900B in many ways. Its color gamut may not be as accurate, but the HC7800’s color temperature tracking is exceptionally tight and gamma performance is remarkably consistent in any mode.

After spending as much time as I needed on color management and getting the gamma right (between 2.3 – 2.4), I leaned back and enjoyed Dragon in good ol’ flat 2D. I also watched a few CBS and NBC prime time TV shows, caught some NCAA men’s basketball, and also a few cartoons; all the while looking for problems with black levels and color saturation. Didn’t see ‘em!

Viewing 3D required me to put on the ‘newly designed’ Mits eyewear, and wow – were they heavy and uncomfortable! I kinda felt like a Navy Seal on a night ops mission wearing these glasses, which supposedly have faster switching times and reduced crosstalk. But they are big and bulky, and not what I expected after using the latest lightweight 3D specs from Samsung and Panasonic. Even the HC9000 specs aren’t as clunky.

Figure 8. No, they're not night vision goggles. But they feel like it.

Despite their weight and discomfort, the glasses worked very well. Indeed; I saw very little crosstalk as I tilted my head back and forth. But I definitely needed to use the gain screen during the nighttime scenes in Dragon and Avatar – 400 lumens just doesn’t cut it with a low-gain or even zero-gain screen. I could have used 2x or even 3x that level of brightness!

So there’s your puzzler: The HC 7800 is a great all-around projector in 2D mode, but challenged to put enough photons on a low-gain screen in 3D mode after calibration. Aside from using two different screens to watch 3D – or a dual-mode screen, like Stewart now offers – you may want to just crank up the brightness and contrast when watching 3D content and not obsess over the gamma performance, or even the color temperature.

CONCLUSION

Amazing what $2,999 (or less) buys you these days. I couldn’t help but compare the HC7800’s 2D performance to the Samsung SP-A900B as I was calibrating it…such a deal! Even if you never watch a single minute of 3D content on this projector, you’d be very happy with it matched to a .85 – .9 gain screen. But 3D mode will require some help from the screen, or a lot brighter lamp setting. And I’m sorry, but Mitsubishi has to re-think the glasses – they are just too bulky and uncomfortable for my taste.

Mitsubishi HC7800 3D DLP Home Theater Projector

SRP: $2,999

Available from:

Mitsubishi Electric Visual Solutions America, Inc.

9351 Jeronimo Road

Irvine, California 92618

Phone: (949) 465-6000

Fax:      (949) 465-6013

www.mevsa.com


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Thursday, February 9, 2012

HDTV Expert - Useful Gadgets: Channel Master CM-7400 TV

For those readers who are either (a) tired of ever-increasing bills for cable TV, or (b) looking for a different TV experience, I’ve got a product for you: Channel Master TV.

This new product from the folks who were formerly best-known for TV antennas, amplifiers, and related products, is an ATSC receiver with dual DVRs (320 GB total capacity) and tuners, plus built-in WiFi connectivity for Vudu’s streaming HD movie service and Vudu apps. If you live in an area with plots of digital TV stations and are content to give up premium news, sports, and lifestyle channels (replacing some of them with Internet-delivered content), then you should check out this product.

WHAT’S IN THE BOX

The CM7400 is a stylish, small (10” W x 7” D x 1.75” H) black box with three ‘rubber duck’ WiFi antennas attached to its rear panel. The front panel has a black gloss finish and shows only the power indicator, current time, and indicator LEDs for menu navigation. There’s also a small USB 2.0 port above the clock.

The rear panel is loaded with jacks, including an RF loop-through (two ‘F’ connectors), component and composite analog video outputs, an HDMI output, a Toslink connector for digital audio, a second USB 2.0 port, a 100BaseT Ethernet port, and an eSATA connection, presumably for an external hard drive. Power for the CM-7400 comes from a small wall transformer – there’s no internal supply.

The supplied remote resembles those shipped by TiVo. It provides the usual secondary control of set-top boxes and other connected gadgets in your system, plus volume, channel, mousedisk, and numeric keypad functions.  It’s actually pretty hefty, compared to the box it’s controlling!

To hook up the CM-7400, your best bet is to use the HDMI port, but if you have an older TV, the analog RCA jacks will suffice. Keep in mind you can only get 720p and 1080i resolutions through component jacks – if you want 1080p playback (24-frame or 30-frame), you’ll need to use the HDMI connector. Digital audio is accessible through the Toslink connector, or embedded in the HDMI hook-up.

Does this remote remind of you anything in particular?

MENUS AND SETTINGS

The first thing you’ll want to do is configure your channels. Go into the Settings menu and select Channels, and the CM-7400 will prompt you for your location. Scroll to the Local Broadcast option and select it (make sure your TV antenna is connected first!). The box will take a few minutes to scan for all local channels and will also start building program guide information from each station’s PSIP data.

You’ll notice that the box can receive digital cable channels that are not scrambled (conditional access) and if you enter your zip code, will ask you for your cable provider. The problem is; most cable systems are moving to scramble all channels in the future, even over-the-air retransmissions. It appears the FCC will give in on this request (they already have with RCN), so plan on sticking to free over-the-air channels.

The next step is to configure your wireless network. (Or, you can simply plug in a wired Ethernet cable, but wireless gives you more options.) The CM-7400 supports 802.11 b/g/n protocols and will connect quickly to your network – if there is a password, you’ll be prompted to enter it on the remarkably easy-to-read menu GUI, which uses mostly white text on a black background.

Channel Master provides a nice Quick Start Guide to get you through these steps, so you should be up and running pretty quickly. Now, it’s time to watch TV.

Here's the top level menu bar.

And here's the program guide interface.

As I mentioned earlier, the CM-7400 uses each station’s Program and System Information Protocol data to build an electronic program guide. That’s how the DVR knows what programs are coming up in the schedule and when to record them. As you tune through each major and minor channel, you’ll see a program synopsis appear in a black bar at the top of the screen. This bar will list the major and minor channel numbers, the program name, its duration, the rating, and a brief description.

You can also press the GUIDE button and a complete program schedule for all receivable stations will appear, showing 30-minute increments. Scroll to a program listing and press OK, and the scheduler will appear, asking you if you want to (a) record the episode, (b) record the series (repeated scheduled recordings), (c) find other times that the program is scheduled, or (d) manually record the program.

The manual feature is handy if your local station isn’t listing program guide information correctly, or it is simply missing, a problem I had with local station WCAU-10 (NBC) a couple of months ago. Scheduling a manual recording without the correct program guide info is not an easy task, as you have to carefully enter a start and stop time and how often you want to record this time block (One Time Only, etc). For all recordings, http://reviews.cnet.com/internet-speed-test/ you can select the record quality, how long to keep it, and if you want the program to start early or end late in one-minute increments.

IN ACTUAL USE

The more I used this product, the more similarities I saw to the TiVo interface, which IMHO is the best GUI around for a DVR. About the only things missing from Channel Master TV are “thumbs up and down” controls, an audible “beep” or “boop” each time you execute a keystroke or command, and the program preference and search functions that make TiVo so powerful. Well, you can’t win them all…

As for the Vudu streaming and apps section, you will see a lot of familiar Internet TV services, including Pandora, Facebook, Picasa, Flickr, and some newbies like NBC Nightly News, New York Times, Associated Press, CNN Daily, and quite a few premium channels like Dexter, Californication, Big Love, and TrueBlood. Just select and click away to start watching.

Here's what the Vudu Apps screen looks like.

And here's the Vudu Movie selection screen. You can choose from SD, HD< or HDX resolution (see text for warnings).

To test out Vudu, I opened an account and purchased two movies – Bridesmaids (or as I like to call it, The Hangover on Estrogen), and The Help. Yeah, they are both chick flicks, but quite entertaining (in fact, Bridesmaids was flat-out hilariously gross!). Vudu gives you the choice of renting using HDX (1080p/24) quality, HD (720p) quality, and SD (480p) quality. The price difference is small, but you need to check first to see how fast your Internet speeds are.

Channel Master TV will do that for you automatically through the Vudu interface and recommend a quality level. But be warned – Internet speeds vary widely  and typically slow down in the evening during peak viewing hours. My suggestion is to go to the CNET Internet Speed Checker Web site (http://reviews.cnet.com/internet-speed-test/) and see what your typical download speeds are during the day and at night. You may find that SD mode works most consistently.

My rule of thumb is – up to 2-3 megabits per second (Mb/s) is good for SD video delivery. Figure on 5-6 Mb/s to get 720p HD content reliably, and 8 Mb/s or better for 1080p video. Otherwise, you may find your movie stops abruptly and the Vudu screen will tell you it is “buffering” – something that can take a few minutes if download speeds drop.

Bridesmaids took four tries to start correctly, then played perfectly in HDX resolution until the past 10 minutes when it stopped and started “buffering” again. I dropped down to SD resolution to finish the movie and it didn’t look all that bad on my Panasonic 42-inch 1080p plasma. The Help ran smoothly except for one hiccup near the middle, but this time, I selected SD playback for the entire film. The reason? My average nighttime Internet speeds were dropping into the 2 – 4 Mb/s range.

As for over-the-air channels, the CM-7400 has a very sensitive receiver and evidently uses sophisticated adaptive equalization. What that means in English is reliable reception of weak stations or stations off to the side of the antenna, as well as good reception during periods of signal fading, such as during a thunderstorm. I was able to lock in and watch 38 different minor channels in the Philadelphia market, which is basically a small hotel cable TV system. And they’re all free.

Sports fans should also keep in mind that there is a growing cry to move all cable sports channels to premium tiers as cable bills continue to climb. You won’t need to pay to watch NFL games (available on CBS, NBC, and FOX through 2022), the NCAA men’s basketball tournament, selected major league baseball games and the World Series, SEC and Big Ten football, and the Olympics – not to mention the Masters golf tournament, selected tennis matches, and the Indianapolis 500. All free with an antenna!

I should mention that the test unit seemed to run a bit warm to me, even when it was switched off. One product review on the Channel Mater Web site recommended using a laptop cooler (external heat sink) to help with heat dissipation. Also, Channel Master released an updated version of the OS on January 18, which you should install and upgrade.

CONCLUSION

Channel Master’s CM-7400 TV DVR is a clever product that nicely combines dual DVRs with Vudu streaming. It has a nicely-designed and executed user interface, sets up quickly, and supports 1080p playback through its HDMI connector. You can also loop your antenna connection through the CM-7400 and continue to watch on your regular TV, giving you the ability to watch three programs at once while recording two of them. Clever, eh?

SPECIFICATIONS

Channel Master CM-7400 TV DVR

SRP: $400

Available at: http://tinyurl.com/7m6qbgk

And other online outlets including Amazon.com

Video

  • 480i/480p
  • 720p
  • 1080p/1080i

Audio

  • Dolby® Digital and Dolby® Digital Plus

Tuners

  • Dual ATSC/Clear QAM¹
  • No monthly subscription fee
  • Includes a one year manufacturer’s limited warranty

Recording Capacity

  • 320GB Hard Disk Drive²
  • Up to 35 hours of HD recording³
  • Up to 150 hours of SD recording³

Wireless

Dimensions

  • 10(w) x 7(d) x 1.75(h) inches

Rear Panel Features

  • RJ-45 Ethernet
  • USB 2.0
  • HDMI®
  • eSATA
  • Digital Audio (Optical)
  • RF output
  • RF antenna/cable input
  • RCA component and composite video
  • Stereo audio

Front Panel Features

  • Illuminated power standby button
  • Indicators for network status, HD and recording status
  • USB 2.0
  • IR receiver
  • Capacitive touchpad
  • Clock display

Contents Included

  • Channel Master TV Unit
  • User Guide
  • Quick Start Guide
  • IR Universal Remote Control
  • AA Batteries
  • Composite and Stero Audio Cable
  • RF Coaxial Cable
  • HDMI Cable
  • AC Adapter



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