Sony MVC-CD400Sony expands its CD-equipped camera line, adding a four megapixel CCD, a huge buffer memory, Hologram Autofocus, and a standard hot shoe!<<Camera Modes & Menus :(Previous) | (Next): Video, Power, Software>> Page 10:Image Storage & InterfaceReview First Posted: 2/20/2002 |
Image Storage and Interface
The MVC-CD400 records still images and movies to a roughly three-inch (80mm)
CD-R or CD-RW disc. This virtually eliminates the hassle of downloading files
from the camera to your computer. Instead of messing around with cables and
driver software, you simply take the CD from the camera and slide it into your
computer's CD-ROM drive. An adapter is provided for those computers that don't
accept the three-inch CD format. (This should be rare though, since the 80mm
CD form factor was part of the original CD specification, so most computers
should accept them.) There's also a USB connection and cable supplied with the
camera (the USB port is in the connector compartment on the lens side of the
camera). The USB connection lets you connect the camera as a disk drive to Windows
computer (Windows 98, 98se, Me, and 2000 Professional are supported). The USB
connection apparently does not support the Mac OS however.
A small CD icon on the camera's LCD display lets you know how much of the disc
is full and how many images are available, depending on the current resolution
and quality settings. An "R" or "RW" below the icon lets
you know what sort of disc is currently loaded in the camera. In Movie mode,
the LCD reports the available recording time at the current movie quality setting.
The CD400 allows you to protect individual images on the disc from accidental
erasure or alteration through the Playback menu. The freedom of a CD-R drive
has many advantages over saving images to floppies (as on some Mavica models),
the main one being an increased amount of storage space -- 156MB.
It's important to note that there's a key limitation in Sony's CD-RW implementation,
in that it's a sequential rewritable device, not a random
access one. The reason for this is that the head movement and data clock
synchronization requirements, which are dictated by true random access operation,
would result in performance (write-time) tradeoffs that are unacceptable for
digital camera applications. Thus, the "RW" aspect of the CD400's
discs has some constraints on it. Foremost is the sequential operation, which
means that you can only delete the last image recorded. That is, you can't open
up more space on a disc by going back and deleting images shot earlier in the
session. You can delete multiple images, but only one at a time, starting
with the most recent and working backward. The huge benefit of CD-RW though,
is that you can "unfinalize" and "format" discs, which (respectively)
helps you save disk space when moving back and forth between camera and computer,
and lets you reuse discs by wiping out all the previously captured images.
A brief note here, in response to some questions I've received about the earlier
CD Mavicas: This issue of what constitutes "erasing" of an image and
what images you can actually erase seems to be the cause of a lot of
confusion. Several people have pointed out that the camera lets them "erase"
images other than the last one shot, and in fact that they can do this on CD-R
discs as well as CD-RW ones. You can always "erase" any image on either
a CD-R or CD-RW disc, but you won't see a corresponding increase in storage
capacity reflective of the space that the deleted image occupied. This is because
"erasing" any image other than the last one shot (or any image
on a CD-R disc) doesn't actually delete the image, but rather merely alters
the disc's directory structure so that the "deleted" image no longer
appears. You can only truly erase the last image on the disc, and then
only on CD-RW media.
There's another generic limitation of CD-RW technology that prospective users
need to be aware of, which is that the signal level delivered to the CD-ROM
drive by CD-RW discs is quite a bit lower than that from normal CD-ROMs or CD-R
write-once discs. Thus, some older CD-ROM drives may have trouble reading the
CD-RW discs. As far as I know, any CD-ROM drive manufactured in the last three
or four years should be able to read a CD-RW disc with no problem, but if you
encounter difficulties, try a different CD-ROM drive before assuming it's a
problem with the CD-RW disc or the CD-300 itself.
Using the CD-Rs in the camera is relatively simple. Whenever a new disc is inserted,
the camera will tell you that it needs to be initialized. Not being a CD maven,
I suspect (but am not sure) that this involves writing the "lead in"
area for the next session, a roughly 9MB area reserved for the table of contents
information for the upcoming session. Initializing the disc appears to be a
more critical operation than normal CD-R recording, as the camera asks you to
place it on a level surface and avoid vibration during the process. Once a disc
has been initialized, operation of the CD400 is the same as for any other Sony
camera, regardless of media.
When you're done with a set of shots and want to set up the CD-R to be read
in a conventional CD-ROM drive, you must "Finalize" the session. The
camera leads you through this process using menu screens similar to those used
for the initialization process. Finalizing also appears to be a more critical
procedure than normal image writing, since the camera again asks you to rest
it on a flat surface. My guess is that this process writes the lead out for
that session, and goes back to fill-in the session's Table of Contents in the
lead-in area. The first lead-out on a disc occupies about 13MB of space, subsequent
ones require about 4MB. The space taken by finalizing and reinitializing a disc
leads to one of the major benefits of CD-RW technology over CD-R. With CD-R,
every time you finalize and reinitialize a disc, you lose about 13MB of storage
space. With CD-RW discs, you can "unfinalize" a disc, recover
that space, and allow the camera to write new images to it. Additionally, unfinalizing
a CD-RW doesn't erase any files. To completely erase all images on a CD-RW,
the CD400 offers a Format option through the Setup menu, which also requires
the camera to rest on a level surface with no vibrations. The Format function
takes several minutes to complete. It's my guess that the camera is actually
rewriting the entire disc, restoring it to a completely blank, initialized state.
NOTE that unfinalizing and formatting are only possible with CD-RW discs, not
ordinary CD-Rs.
In addition to finalizing a disc, the Playback settings menu allows you to write-protect,
delete (sequentially), resize, or rotate individual images. When an image is
resized, the original version is left where it is on the CD, and a new copy
is appended to the end of the list of images, resized to the dimensions you
selected. Rotation is much more confusing. The original image actually remains
in place (even on a CD-RW disc), and a new, rotated version is recorded. The
camera edits the directory structure of the disc though, so the new rotated
version appears in the same place as the original, in the list of images
as you step through them sequentially, or view them as thumbnails. Although
the original image is still physically recorded on the disc, it is no longer
accessible to either the camera or a computer. (I'm not sure, but some data-recovery
programs may be able to retrieve "overwritten" or "deleted"
files like this from the CD-R discs.)
You can also designate whether the camera numbers each image sequentially (from
one CD to the next), or restarts file numbering with each new CD, by making
a change in the Setup menu. The camera's Digital Print Option Format (DPOF)
compatibility allows you to mark specific images for printing. Through the Setup
menu you can decide whether or not to print the date and/or time on the image
as well.
Image Size options include 2,272 x 1,704, 2,272 (3:2 ratio), 1,600 x 1,200,
1,280 x 960, 640 x 480, and 320 x 240 pixels (E-Mail recording option). Movie
file sizes are 320 (HQ), 320 x 240, and 160 x 112 pixels for MPEG Movies, or
160 x 120 and
80 x 72 pixels for Clip Motion files. In addition to the uncompressed
TIFF file format, the CD400 offers both Fine and Standard JPEG compression levels,
and a GIF option for the Clip Motion recording mode.
The table below shows the approximate still image capacities and compression
ratios for the CD-R disc (main resolution sizes):
Resolution/Quality (CD-R disc) |
|
|
|
|
Highest Resolution 2272x1704 | Images | 9 | 65 | 119 |
Approx. Compression |
1:1 | 5:1 | 9:1 | |
High Resolution 1600x1200 | Images | N/A | 131 | 235 |
Approx. Compression |
N/A |
|
9:1 | |
Standard Resolution 1280x960 | Images |
|
|
|
Approx. Compression |
|
|
|
|
Low Resolution 640x480 | Images |
|
|
|
Approx. Compression |
|
|
|
A note about media: Whenever you put a non-Sony CD-R or -RW into the CD400, it flashes the message "Mavica DISC RECOMMENDED" on the LCD as it starts up. For the record, non-Sony CD-Rs seemed to work just fine in my test unit, but prior conversations with Sony technical staff revealed that inexpensive third-party media sometimes has problems with concentricity between the center hole and the data tracks, which can cause read/write problems. I never encountered this while working with third-party media in various Sony CD Mavicas, but just now did have a problem with expanded-capacity media in the CD400 test unit I have. Expanded-capacity CD-R media has been commonplace with full-sized CDs for some years now: The standard spec for full-sized CDs is a capacity of roughly 650 megabytes, but 700 megabyte discs are now quite common. In the same fashion, while the "official" spec for 80mm media is a capacity of 156 MB, you can find third-party discs on the market with capacities of 185 MB. This is an appreciable increase in capacity, to the extent that you might be tempted to give it a try. If you do, I'd advise checking it out carefully before you entrusted your precious photos to it. I was using a 185 MB disc in the CD400 during some of my test shooting, and ended up needing to reshoot a series of test photos. The problem was that, while the camera appeared to recognize and utilize the expanded capacity, after finalizing the disc, I was unable to retrieve the last dozen or so shots I'd recorded on the disc. It's possible that I might be able to access those photos via the USB port, but I haven't had time yet to wrestle with the software on my balky main Windows PC. Even if it does work in that scenario, I'd still advise against using expanded-capacity media as an inherently risky proposition.
Notes for Mac owners: In order to avoid a 1MB limit on writeable file size, Sony had to go with the Level 3 ISO CD standard, which supports larger data sizes in packet-writing mode. This means that Macs need a UDF format extension to be able to read the resulting discs. NOTE that the "UDF Volume Access" extension that ships with OS9 is apparently not adequate to the task. Although Apple's UDF Volume Access claims support for Version 1.5 of the UDF ("Universal Disk Format (tm)") specification, the Adaptec UDF Volume Access Version 1.04 extension is apparently required to read the version of the UDF format used by the Mavica MVC-CD400. I can, however attest to the fact that the iMac supports both the 80mm disc size, as well as the Adaptec Volume Access extension, as I was able to successfully read "finalized" CDs from the MVC-CD400 on our slot-loading iMac. (A 400MHz DV model, running Mac OS 9.0.4.)
Lost Images? - Download this image-recovery program so you'll have it when
you need it...
Since we're talking about memory and image storage, this would be a good time
to mention the following: I get a ton of email from readers who've lost photos
due to a corrupted memory card. It's tragic when it happens, there are few things
more precious than photo memories. Corrupted memory cards can happen with any
card type and any camera manufacturer, nobody's immune. "Stuff happens,"
as they say. A surprising number of "lost" images can be recovered
with an inexpensive, easy to use piece of software though. Given the amount
of email I've gotten on the topic, I now include this paragraph in all my digicam
reviews. The program you need is called PhotoRescue, by DataRescue SA. Read
our review of it if you'd like, but download the program now,
so you'll have it. It doesn't cost a penny until you need it, and even then
it's only $29, with a money back guarantee. So download PhotoRescue for
Windows or PhotoRescue for
Mac while you're thinking of it. (While you're at it, download the PDF
manual and quickstart
guide as well.) Stash the file in a safe place and it'll be there when you need
it. Trust me, needing this is not a matter of if, but when... PhotoRescue
is about the best and easiest tool for recovering digital photos I've seen.
(Disclosure: IR gets a small commission from sales of the product, but I'd highly
recommend the program even if we didn't.) OK, now back to our regularly
scheduled review...
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