M6E3US.book  Page 1  Tuesday, February 21, 2006  12:36 PM
INSTRUCTIONS
HARD DISK CAMCORDER
GZ-MG21U
To deactivate the demonstration mode, set “DEMO 
MODE” to “OFF”. (墌 pg. 51) 
Dear Customer,
Thank you for purchasing this hard disk camera. Before 
use, please read the safety information and precautions 
contained in pages 4 and 5 to ensure safe use of this 
product.
MasterPage: Cover
ENGLISH
GETTING STARTED
RECORDING
PLAYBACK
EDITING/PRINTING
DUBBING
MENU SETTINGS
FURTHER 
INFORMATION
8
16
20
26
30
36
47
50
56
For Customer Use: 
Enter the Model No. (located on 
the bottom of the camera) and 
Serial No. (located on the battery 
pack mount of the camera) below. 
Retain this information for future 
reference.
Model No.
Serial No.
LYT1591-001C EN
M6E3US.book  Page 2  Tuesday, February 21, 2006  12:36 PM
2 EN
Major Features
The camera has a built-in high-capacity HDD (hard disk drive) that enables you to record videos and 
still images in massive quantities.
● To record videos (墌 pg. 16)
● To playback videos (墌 pg. 26)
● To record still images (墌 pg. 20)
● To playback still images  
(墌 pg. 30)
SD Memory Card
You can also record onto 
SD cards.
 “When Using an SD 
Card” (墌 pg. 15)
Auto/Manual Recording Mode
You can record without using any complicated 
operations in Auto recording mode.
Manual recording mode, on the other hand, enables 
you to use special effects and make manual 
adjustments to record videos that are even more vivid.
“To change to manual recording mode” (墌 pg. 22)
Video Event 
Registration
(墌 pg. 17)
You can register recorded videos to 
events according to their content. This 
enables you to search and select files by 
content (event).
Editing Files on Your PC
(墌 SOFTWARE INSTALLATION  
AND USB CONNECTION GUIDE)
USB 2.0 enables the smooth transfer of 
video and still images to a computer. 
With the bundled image editing software, 
you can easily edit video and create your 
own DVDs.
Direct Printing
(墌 pg. 46)
If your printer is compatible with 
PictBridge, still images can be printed 
easily by connecting the camera directly 
to the printer with a USB cable. 
M6E3US.book  Page 3  Tuesday, February 21, 2006  12:36 PM
Read This First! – How to Handle the Hard Disk Camera
EN 3
Please read the following instructions before 
using the camera.
Make a backup of important recorded data
It is recommended to copy your important recorded 
data to a DVD or other recording media for storage. 
(墌 pg. 47)
Make a trial recording
Before the actual recording of important data, 
make a trial recording and play back the recorded 
data to check that the video and sound have been 
recorded correctly.
Check the compatibility of recording 
media
● The SD cards that are guaranteed to work with 
this camera are those by Panasonic, TOSHIBA, 
pqi (still image only) and SanDisk. If other media 
are used, they may fail to record data correctly, or 
they may lose data that had already been 
recorded.
● For video recording, use a high-speed SD card 
(at least 10 MB/s).
● MultiMediaCards are not supported.
Format recording medium before use
Before using this camera, format the built-in hard 
disk or SD cards. This will also ensure stable 
speeds and operation when accessing the 
recording medium. (墌 pg. 39)
Make sure you hold the camera correctly 
during recording
Do not cover the area near the lens, stereo 
microphone, or camera sensor with your finger or 
other object while recording. (墌 pg. 10) 
When a certain length of time passes 
without operation
● When using the battery, the power will turn off 
automatically to conserve power. Use the power 
switch to turn on the power again.
● When using the AC adapter, the access lamp 
lights up, and the LCD turns off (the camera 
enters the sleep mode).
Reset the camera if it does not operate 
correctly
This camera uses a microcomputer. Factors such 
as background noise and interference can prevent 
it from operating correctly. If the camera does not 
operate correctly, reset the camera. (墌 pg. 56)
If a problem occurs with the SD card, bring 
the card together with the camera for 
repairs
When requesting repairs for breakdowns by your 
dealer or JVC service center, be sure to bring your 
camera together with the SD card. If one of them is 
not included, the cause cannot be diagnosed, and 
the repair cannot be made properly.
Precautions on handling batteries
● When discarding batteries, environmental 
problems must be considered and the local rules 
or laws governing the disposal of these batteries 
must be strictly followed.
● If the camera is subjected to electrostatic 
discharge, turn the power off before using it 
again.
● This product includes patented and other 
proprietary technology and will only operate with 
a JVC Data Battery. Use the JVC BN-VF707U/
VF714U/VF733U battery packs. Using generic 
non-JVC batteries can cause damage to the 
internal charging circuitry.
● If the battery operation time remains extremely 
short even after the battery is fully charged, the 
battery is worn out and needs to be replaced. 
Please purchase a new one.
● Since the AC adapter processes electricity 
internally, it becomes warm during use. Be sure 
to use it only in well-ventilated areas.
● After 5 minutes has elapsed in record-standby 
mode, the camera will automatically turn off its 
power supplied from the AC adapter. In this case, 
battery charge starts if the battery is attached to 
the camera.
INFORMATION
Video recording (with sound) that was made 
especially for demonstration at shops might be 
remaining on the hard disk of the camera that you 
have purchased.
To delete this video file, please refer to “Deleting 
Files” (墌 pg. 36)/“Formatting a Recording 
Medium” (墌 pg. 39).
M6E3US.book  Page 4  Tuesday, February 21, 2006  12:36 PM
4 EN
Safety Precautions
CAUTION
DO NOT OPEN
RISK OF ELECTRIC SHOCK
CAUTION:      TO REDUCE THE RISK OF ELECTRIC SHOCK,
       DO NOT REMOVE COVER (OR BACK).
NO USER-SERVICEABLE PARTS INSIDE.
REFER SERVICING TO QUALIFIED SERVICE PERSONNEL. 
The  lightning  flash  with  arrowhead  symbol,  within  an 
equilateral  triangle,  is  intended  to  alert  the  user  to  the 
presence of uninsulated "dangerous voltage" within the 
product's enclosure that may be of sufficient magnitude 
to constitute a risk of electric shock to persons.
The  exclamation  point  within  an  equilateral  triangle  is 
intended to alert the user to the presence of important 
operating  and  maintenance  (servicing)  instructions  in 
the literature accompanying the appliance.
WARNING: TO PREVENT FIRE OR SHOCK 
HAZARD, DO NOT EXPOSE THIS UNIT TO 
RAIN OR MOISTURE.
NOTES:
● The rating plate and safety caution are on the 
bottom and/or the back of the main unit.
● The serial number plate is on the battery pack 
mount.
● The rating information and safety caution of the 
AC adapter are on its upper and lower sides.
Caution on Replaceable lithium battery
The battery used in this device may present a 
fire or chemical burn hazard if mistreated.
Do not recharge, disassemble, heat above 
100°C or incinerate.
Replace battery with Panasonic (Matsushita 
Electric), Sanyo, Sony or Maxell CR2025.
Danger of explosion or Risk of fire if the battery 
is incorrectly replaced.
● Dispose of used battery promptly.
● Keep away from children.
● Do not disassemble and do not dispose of in 
fire.
When the equipment is installed in a cabinet or 
on a shelf, make sure that it has sufficient space 
on all sides to allow for ventilation (10 cm (3-15/
16") or more on both sides, on top and at the 
rear).
Do not block the ventilation holes.
(If the ventilation holes are blocked by a 
newspaper, or cloth etc. the heat may not be 
able to get out.)
No naked flame sources, such as lighted 
candles, should be placed on the apparatus.
When discarding batteries, environmental 
problems must be considered and the local rules 
or laws governing the disposal of these batteries 
must be followed strictly.
The apparatus shall not be exposed to dripping 
or splashing.
Do not use this equipment in a bathroom or 
places with water.
Also do not place any containers filled with water 
or liquids (such as cosmetics or medicines, 
flower vases, potted plants, cups etc.) on top of 
this unit.
(If water or liquid is allowed to enter this 
equipment, fire or electric shock may be 
caused.)
Do not point the lens directly into the sun. This 
can cause eye injuries, as well as lead to the 
malfunctioning of internal circuitry. There is also 
a risk of fire or electric shock.
CAUTION!
The following notes concern possible physical 
damage to the camera and to the user.
Carrying or holding the camera by the LCD 
monitor can result in dropping the unit, or in a 
malfunction.
Do not use a tripod on unsteady or unlevel 
surfaces. It could tip over, causing serious 
damage to the camera.
CAUTION!
Connecting cables (Audio/Video, S-Video, etc.) 
to the camera and leaving it on top of the TV is 
not recommended, as tripping on the cables will 
cause the camera to fall, resulting in damage.
M6E3US.book  Page 5  Tuesday, February 21, 2006  12:36 PM
EN 5
Remember that this camera is intended for 
private consumer use only.
Any commercial use without proper 
permission is prohibited. (Even if you record 
an event such as a show, performance or 
exhibition for personal enjoyment, it is 
strongly recommended that you obtain 
permission beforehand.)
Trademarks
● Manufactured under license from Dolby 
Laboratories. “Dolby” and double-D symbol are 
trademarks of Dolby Laboratories.
●
MascotCapsule is a registered trademark of HI 
CORPORATION in Japan.
Copyright © 2001 HI CORPORATION. All 
rights reserved.
● Other product and company names included in 
this instruction manual are trademarks and/or 
registered trademarks of their respective 
holders.
IMPORTANT SAFETY INSTRUCTIONS
1. Read these instructions.
2. Keep these instructions.
3. Heed all warnings.
4. Follow all instructions.
5. Do not use this apparatus near water.
6. Clean only with dry cloth.
7. Do not block any ventilation openings. Install 
in accordance with the manufacturer’s 
instructions.
8. Do not install near any heat sources such as 
radiators, heat registers, stoves, or other 
apparatus (including amplifiers) that 
produce heat.
9. Only use attachments/accessories specified 
by the manufacturer.
10. Use only with the 
cart, stand, tripod, 
bracket, or table 
specified by the 
manufacturer, or 
sold with the 
apparatus. When 
a cart is used, use 
caution when moving the cart/apparatus 
combination to avoid injury from tip-over.
11. Unplug this apparatus during lightning 
storms or when unused for long periods of 
time.
12. Refer all servicing to qualified service 
personnel. Servicing is required when the 
apparatus has been damaged in any way, 
such as power-supply cord or plug is 
damaged, liquid has been spilled or objects 
have fallen into the apparatus, the 
apparatus has been exposed to rain or 
moisture, does not operate normally, or has 
been dropped.
M6E3US.book  Page 6  Tuesday, February 21, 2006  12:36 PM
6 EN
Contents
GETTING STARTED
Accessories  .......................................................8 
Attaching the Shoulder Strap  .........................9
Attaching the Lens Cap ..................................9
Attaching the Core Filter  ................................9 
Index ..............................................................10 
Necessary Settings before Use  .........................12 
Power Related Preparations (Using the Battery 
Pack) ............................................................12
Language Setting .........................................13
Date/Time Setting  ........................................13 
Other Settings .................................................14 
Grip Adjustment  ...........................................14
Tripod Mounting  ...........................................14 
Data Battery System  ....................................14
When Using an SD Card ..............................15 
RECORDING
Video
Video Recording  ..............................................16
Registering Files to Events  ..........................17 
Zooming  .......................................................18
16:9 Mode  ....................................................18
LED Light  .....................................................18 
Deleting a File  ..............................................19
Checking the Remaining Space on the 
Recording Media ..........................................19
Still image
Still Image Recording  .......................................20
Zooming  .......................................................21 
Continuous Shooting ....................................21
LED Light  .....................................................21 
Deleting a File  ..............................................21 
Video / Still image
Manual Recording ............................................22
Manual Setting in MSET Menu  ....................22
Nightalive  .....................................................25
Backlight Compensation  ..............................25
Spot Exposure Control .................................25
PLAYBACK
Video
Video Playback  ...............................................26
Various Operations during Playback  ........... 27
File Search Function .................................... 28
Date Index Screen ................................... 28
Event Screen  ........................................... 29
To Play Back Files in the [EXTMOV] Folder ..... 29
Deleting a Video File  ................................... 29
Still image
Still Image Playback  ........................................30
File Search Function .................................... 30
Slide Show ................................................... 31
Image Rotation  ............................................ 31
Playback Zoom ............................................ 31
Deleting a Still Image File ............................ 31
Video / Still image
Watching Images on TV/Remote Control  ..........32
Connecting to a TV, VCR or DVD Recorder ....... 32
Playback on TV  ........................................... 32
Playback Using the Remote Control ............ 33
Playback with Special Effects  ...........................34
EDITING/PRINTING
Video / Still image
Managing Files ................................................36
Deleting Files ............................................... 36
Viewing File Information  .............................. 37
Protecting Files from Accidental Erasure .......38
Formatting a Recording Medium  ................. 39
Cleaning Up a Recording Medium ............... 40
Resetting the File Number ........................... 40
Changing the Event Registration of Video Files 
after Recording  ............................................ 41
M6E3US.book  Page 7  Tuesday, February 21, 2006  12:36 PM
Video
Playlists  .........................................................42
Creating Playlists ......................................... 42
Playing Back Playlists .................................. 44
Other Operations of Playlists ....................... 44
Still image
Print Setting  ...................................................45
DPOF Print Setting  ...................................... 45
Direct Printing with PictBridge Printer .......... 46
DUBBING
Video
Dubbing Video Files to DVD Discs .....................47
Using a VCR/DVD Recorder for Dubbing  .... 47
Still image
Copying/Moving Still Image Files .....................48
MENU SETTINGS
Changing the Menu Settings .............................50
Common Menus for All Modes  .................... 51
Video Recording Menus  .............................. 53
Video Playback Menus  ................................ 54
Still Image Recording Menus ....................... 55
Still Image Playback Menus ......................... 55
FURTHER INFORMATION
Troubleshooting  ..............................................56
Warning Indications .........................................60
Cleaning the Camera ........................................62
Cautions  .........................................................63
Specifications  ..................................................66
Indications on LCD Monitor  ..............................68
TERMS  ..............................................  Back cover
EN 7
Regarding This Manual
Button operations
● Button operations are illustrated as shown 
below.
ex.)
● Regarding the control lever (墌 pg. 11)
There are two kinds of operation using the 
control lever: moving the lever towards up/
down/left/right, or pressing down the lever. 
They are described and illustrated as shown 
below.
ex.)
1) Move the control lever downward:
Press 
.
2) Press down the control lever:
Press 49. 
3) Operate 1) and 2) continuously:
Select
Set
/
Press 
 
to select, then press 
49.
/
/
Icons at the top of pages
EN 27
otion playback
sed
Backward
Forward
When there are icons at the top of pages, they 
show whether the page is related to videos and/or 
still images. 
Page related to videos
Page related to still images
Page common to videos and still 
images
M6E3US.book  Page 8  Tuesday, February 21, 2006  12:36 PM
8 EN
Accessories
or
AC Adapter 
AP-V18U / AP-V14U
Battery Pack 
BN-VF707U
Audio/Video Cable
USB Cable 
(墌 SOFTWARE 
INSTALLATION AND 
USB CONNECTION 
GUIDE)
Shoulder Strap 
(墌 pg. 9)
Lens Cap (墌 pg. 9)
CD-ROM
Remote Control Unit 
RM-V730U (墌 pg. 33)
Lithium Battery 
CR2025 (for remote 
control unit)
Pre-installed in the 
remote control unit at 
time of shipment.
Core Filter for Cables (墌 pg. 9)
Large (A): Audio/Video Cable
Large (B): USB Cable
Small: DC Cord