Sony Mavica CD200Sony expands its CD-equipped camera line, adding erasability, buffer memory, and a more compact case!<<Camera Modes & Menus :(Previous) | (Next): Video, Power, Software>> Page 10:Image Storage & InterfaceReview First Posted: 3/9/2001 |
Image Storage and Interface
The MVC-CD200 records still images and movies to a 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).
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 resolution size 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, but note that this is total recording time. Individual movies can only be as long as allowed by the camera hardware, based on the MPEG-EX limits described earlier.) The CD200 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 other Mavica models), the main one being an increased amount of storage space -- 156MB.
The implementation of rewritable (CD-RW vs. CD-R) technology on the CD200 addresses a common objection raised with the original CD1000 model. Even though good-quality 80mm CD-R discs are available on the internet for less than $2 each, many in the digicam community objected to the concept of write-once media. (Personally, we didn't see it as being an issue. After all, at approximately two cents per image, you can hardly claim it's too expensive, but because we're all accustomed to there being no cost associated with snapping digital photos, any cost seems onerous.) There are some other very practical benefits to the rewritable technology that we'll delve into as we discuss the technology.
It's also 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 CD200'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.
There's another generic limitation of CD-RW technology that prospective users need to be aware of: 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 we know, any CD-ROM drive manufactured in the last two to three 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 CD200 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 CD mavens, we suspect (but aren't 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 CD200 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. Our 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 re-initializing a disc is one of the major benefits of CD-RW technology over CD-R. With CD-R, every time you finalize and re-initialize 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 -- and unfinalizing a CD-RW doesn't erase any files. To completely erase all images on a CD-RW, the CD200 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 our 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. Some notes on rotation and resizing: 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. (We're 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 2,048 x 1,536, 2,048 x 1,536 (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 CD200 offers both Fine and Standard JPEG compression levels, and a GIF option for Text and Clip Motion recording modes.
The table below shows the approximate still image capacities and compression ratios for the CD-R disc (main resolution sizes):
| Image Capacity VS Resolution/Quality |
Uncompressed TIFF
|
Fine Quality
|
Standard Quality
|
|
|
Highest Resolution
2048 x 1536 |
Images
|
11
|
79
|
142
|
|
Approx. Compression
|
1:1
|
5:1
|
9:1
|
|
|
High Resolution
1600 x 1200 |
Images
|
12
|
128
|
229
|
|
Approx. Compression
|
1:1
|
5:1
|
9:1
|
|
|
Standard Resolution
1280 x 960 |
Images
|
12
|
190
|
337
|
|
Approx. Compression
|
1:1
|
5:1
|
8:1
|
|
|
Low Resolution
640 x 480 |
Images
|
13
|
641
|
1256
|
|
Approx. Compression
|
1:1
|
4:1
|
7:1
|
|
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-CD200. We can, however attest to the fact that the iMac supports both the 80mm disc size, as well as the Adaptec Volume Access extension, as we were able to successfully read "finalized" CDs from the MVC-CD200 on our slot-loading iMac. (A 400MHz DV model, running Mac OS 9.0.4.)
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