Video Accessories Misc
- Written by John E. Johnson, Jr.
- Published on 16 November 2009
- JVC GZ-HM400U High Definition Video Camera
- Page 2: The Design of the JVC GZ-HM400U High Definition Video Camera
- Page 3: The JVC GZ-HM400U High Definition Video Camera In Use
- Page 4: The JVC GZ-HM400U High Definition Video Camera On the Bench
- Page 5: Conclusions About the JVC GZ-HM400U High Definition Video Camera
- All Pages
I remember when the first consumer HD video camera hit the shelves. I saw one in a store connected to a monitor, and as I stood in front of the camera and saw myself in high definition, I knew the world of photography had reached a new milestone. Although it looked terrific to me at the time, now, after having tested so many video cameras over the past few years, I realize the camera I saw in the store that day probably did not have a really sharp image.
If you have followed our reviews of HD video cameras, you remember that the first ones were called HDV, and what that actually meant was that the resolution was 1440 x 1080 rather than 1920 x 1080. I think this actually had something to do with making it easier to record both standard def (SD) and HD using the same camera circuitry (1440 x 1080 is 4:3 just like SD). Some Pro-sumer (midway between professional and consumer) cameras stuck to 720p rather than trying to do 1080i.
- Design: Single-chip Full High Definition (1920 x 1080) Video Camera
- Sensor: 0.43" CMOS, 10.29 Megapixels
- Lens: f/6.7mm - 67mm, F 2.8 - 4.5
- LCD Monitor: 2.8
- Recording: 1080i60; AVCHD; 24, 17, 12, 5 Mbps
- Records Short Segments at 200, 300, and 600 Frames per Second for Slow Motion Playback
- Media: Built-in 32 GB Memory Card
- Dimensions: 2.9" H x 2.7" W x 5.4" D
- Weight: 1.1 Pounds with Battery
- MSRP: $1,199 USA
Anyway, technology progressed, and for about two years, consumer HD cameras began to deliver native 1920 x 1080 video. However, as we have shown, it is not simply a matter of the sensor having enough pixels for 1920 x 1080. The lens is a huge factor, and as prices had to stay in the $1,200 range in order to sell, the lenses could not be significantly improved and keep the price down. So, we saw resolution (MTF-50 sharpness number defined as "resolution") in the 300 Line Widths per Picture Height (LW/PW) range, indicating that although the video was 1920 x 1080, the picture quality had a way to go before it would be considered truly "high definition".
Part of the problem also was that the sennsors had barely enough pixels for high definition, and that issue stayed with the industry for about a year.
This has changed recently with the introduction of HD video cameras that have sensors with much higher pixel count. This does two things. One is that it lets the user take high resolution snapshots with the video camera, similar in resolution to a dedicated digital snapshot camera. But, secondly, it provides a huge overhead in pixel count for getting a good 1920 x 1080 video image.
The JVC GZ-HM400U is a consumer-oriented camera, with a single 10.3 megapixel sensor. It weighs just over one pound, and fits into one's hand easily.
Simply opening the LCD screen (folding it outward) turns the camera on, and it will remain in standby when the screen is closed. If you want to turn the camera off, you need to press the power button on the inside panel (located under the Dolby license statement in the photo below).
Also located on that panel are a USB jack and various function buttons.
The battery is mounted on the rear of the camera, and the AC adapter (included) plugs into a small jack on the rear, so you don't have to remove the battery to recharge it.
I found that the battery lasted longer before needing recharging than I usually see in cameras when I am testing them. I don't know if this is just more conservative battery use by the camera's electronics or that batteries are continuing to improve on the amount of power they can store.
The AC adapter is also much smaller than conventional battery chargers. This one is a single piece design, whereas other chargers tend to be in two pieces that have to be connected together for use, mainly because you have to remove the battery from the camera and place it in the charger tray.
The top of the camera has the zoom control, which also serves as a volume control when reviewing what you have recorded. The recorded files (*.mts) are stored on a built-in 33 GB memory chip. You can also insert additional HC-SD memory cards, but even at the highest quality recording rate (24 Mbps), you can get nearly 3 hours of video on the built-in memory. The three buttons near the bottom of the photo are for use in Manual mode, such as adjusting the aperture or shutter speed.
At the front of the camera are manual focus and brightness adjustments, again, which can be used when in the Manual mode.
The remote control has all the basic functions.
Nearly all of the camera's features are accessed by touching controls on the LCD panel. In the photo below, the display button has been activated so that you can see that it is in Auto mode (the green A), recording in UXP, which is the highest quality, the face recognition feature is active, there are 2 hours and 46 minutes of recording time available on the built-in memory, and the battery is fully charged. To begin recording, you can either touch the button under the REC on the LCD screen, or press the record button on the rear of the camera. I found that it was easier to use the record button on the LCD panel (you can also zoom from the panel), than to reach behind the camera to begin or stop recording.
To the left is a touch-panel where you slide your finger up or down to select menu items. To turn on the menu, you touch the Menu button (it is actually an indentation rather than something that sticks outward).
The menu system is very simple and easy to use (as well as easy to read, with nice big letters).
When you want to upload your videos to your PC for editing, you connect the included USB cable to the USB jack on the inside panel and the other end to a USB jack on your PC.
The camera LCD screen will then show this menu (shown below).
Using a finger to slide on the touch panel, move the selection to "Export to Library", and press "Set", which then changes the screen to the one shown below.
At this point, your PC will recognize the camera as a drive, and you can go into the various directories, where you will find "Stream". This directory contains your videos, with the extension *.mts. Highlight them all with <Ctrl><a>, then move your mouse to a selected directory on your PC hard drive. You can then delete the files on the camera's memory card. There are lots of software programs for video editing out there, and the one I use most often is Pinnacle Studio (which is currently at version 14). It will recognize *.mts files and will also let you burn your edited video onto a standard DVD-R in AVHCD format, which will play on your Blu-ray player. A DVD will hold about 30 minutes of HD video in this form, compared to the 2 hours you could record onto a Blu-ray recordable disc, but a DVD-R costs 20 cents and recordable Blu-ray media are about $20 each. So, it is an easy choice to make, and 30 minutes is enough for most videos. I record them as part of my family video album, and if the video requires more than 30 minutes, I break it up into two parts, split evenly onto two DVDs so I don't end up with 30 minutes on the first disc and 3 minutes on the second.
All photos are single video frames, unaltered, except for sizing to fit on these pages. I shot all videos in the UXP mode, which is the highest quality (24 Mbps). I set the camera to Auto. Note that this camera does not have an option for 1080p30 or 1080p24. It only shoots at 1080i. (However, it does have a feature allowing you to shoot at 200, 300, or 600 frames per second for slow motion playback. I am still experimenting with this feature and will post a video when I find the right subject matter to fully illustrate the effect.)
The optical zoom ratio (10:1) is very high for a camera priced in the $1,000 range. It also operated very smoothly. Although you can zoom from the slider on the LCD panel, I preferred to use the controls on the top of the camera.
There seemed to be no problem in leaving the camera in standby mode all day long when I was shooting, rather than using the power button inside the panel to turn it off completely. The advantage of the standby mode is that you can grab the camera and start shooting quickly if the occasion arises, which it did from time to time while I had the camera here for review.
In low light, the camera produced images that were a bit noiser than previous models I have tested. This may have something to do with the smaller pixel size (the sensor has 10 megapixels in nearly the same size - actually a bit larger - that other cameras have 2), but I am assuming that the image is produced by combining the voltage from several adjacent pixels in the down-conversion procedure, so I am a little surprised at this finding.
Red is a tough one for digital cameras, but as long as the red is not over the entire field of view, you can get realistic shots, such as this bowl of tomatoes, with a green lime in the background.
You can always tell the time of year I reviewed a particular camera if I show a photo of a tree with red leaves, which are all over my yard on gum trees in October and November. Again, there is a significant amount of other color (green) in the shot, so the red is not over-saturated.
Once you try to get a video that has almost entirely red, that is when the oversaturation problem occurs.
Purple is kind of difficult as well. This is pretty close to realistic, but a bit oversaturated. But, the green is spot on.
Another example of beautiful green reproduction.
Blue is an easy one for digital cameras (the image of a leaf at the top left). However, even though I used Auto mode (which includes auto white balance), there was an obvious blue shift. This is something for correction during the editing process (I probably would add some brightness as well).
Here is a white rose, but again, it looks slightly blue.
Yellow? A problem for some cameras, but not this JVC.
This is a photo of Silicon Valley when it gets fogged over. It shows the limted dynamic range of digital sensors (about 11 EV), compared to film (15 EV). You can't see very much detail in the bushes and trees.
If the dynamic range is not quite so much, as shown in this photo of my bowl of cereal (with cranberries) at breakfast, with the morning light coming mostly from the side, then shadow detail (the inside left portion of the bowl) is much better.
And now, the notorious grocery store vegetable rack. The color (tint) was right on target, but the image was slightly underexposed.
On the Bench
Cameras that I tested some time ago tended to have significant falloff, but the JVC is very good in this regard. In wide angle, the worst falloff was only 0.113 f-stops, and in telephoto, 0.311 f-stops. This is excellent lens performance.
Resolution (sharpness) results are shown below. The MTF-50 value was 0.494 cycles/pixel, or 1067 LW/PH. The theoretical limit is 0.5 cycles per pixel and 1080 LW/PH, so this is very close, and certainly the best I have seen in any video camera I have tested. These numbers can go higher than the theoretical limit if there is a large amount of sharpening added by the camera's video processing circuitry, and the "hump" in the black line near the top of the graph midway across the graph indicates some sharpening has been applied.
Keep in mind these data represent the visible lines at 50% contrast. The "perfect" camera would have an MTF-100 value of 1080 LW/PH, meaning 1080 lines going horizontally across the screen at 100% contrast (absolute black lines adjacent to absolute white lines). We may now need to raise the bar for the tests to MTF-75.
Chromatic aberration was 0.629 pixels, not the best I have seen, but certainly not the worst.
The gray scale test results (below) indicate that the camera subdues the whites at the upper end of the scale. This prevents highlight blowout. The video noise level was about average, and because it is nearly the same across the various brightness levels, but does rise slightly at the darkest zones, I would think that a low amount of noise reduction is being applied.
The Kodak Q-60 color target had the colors right, but was a bit underexposed.
The Gretag color test chart showed over-saturation, and also was a bit over-exposed.
A different chart analysis of the Gretag test pattern (a series of color chips) shows the over-saturation in some of the colors, as the circles (representing the way the camera reproduced a specific color) are more towards the outside of where the reference colors are located (squares). White is at the center of the chart. Maximum saturation for a specific color is at the periphery of the chart.
I requested the JVC GZ-HM400U because it has a sensor with a high pixel count, thinking that perhaps this would result in higher quality video, and I guessed right. Its sharpness value is as about as good as it gets, and is the best we have seen so far. At a street price of $1,099 it is also a great value. You could pay twice this price and get less performance.