IMovie 08 degrades movie quality

Question

When I open iMovie, my camera (JCV MG130) is detected and the movies are being imported into the iMovie library. So far things couldn't be better! However, when I export a movie clip to a file using "Share" -> "Export To Movie" and "Large 960x540" resolution, the picture quality of the exported movie is clearly degraded compared to the original file that was downloaded from the camera.
*Does iMovie have a loss-less export function?*
Additional comment:
Overall, my experience with iMovie 08 (and iDVD 08) on my Leopard MacBook Pro is mixed. Great idea, but too many short comings. Example: when I want to create a DVD, I need to import/edit/export a movie in iMovie, then I need to import that movie file into iDVD (if I just open iDVD and load an iMovie project, iDVD crashes). This adds an additional step and it takes twice as long to render a movie (1/2hr clips takes 1 hr to render to file in iMovie, another hour to burn the movie to a DVD using iDVD). Clearly, this should be ONE step. If I want to index the movie, I have to import/export using Garageband, etc. In addition with the degradation of the movie quality as discussed above, I think iMovie and iDVD are more toys than serious applications. I would have expected more from Apple, to be honest.

Answer 1

When I open iMovie, my camera (JCV MG130) is detected and the movies are being imported into the iMovie library. So far things couldn't be better! However, when I export a movie clip to a file using "Share" -> "Export To Movie" and "Large 960x540" resolution, the picture quality of the exported movie is clearly degraded compared to the original file that was downloaded from the camera.
According to what I read concerning this model, it is a "Standard Definition" HDD camcorder. You should expect such degradation when sharing/exporting SD content at HD resolutions. This is the same as taking a 640x480 JPEG photo and enlarging it to 960x540, printing, and then comparing your output quality with that of your original picture. Enlarging the frame size in iMovie does not add resolution detail that did not exist in your original source file.
Does iMovie have a loss-less export function?
No. Unlike earlier versions of iMovie, the source files (in all of their various possible compression formats) are never stored as physical clip. Instead, all content remains in its original form and is manipulated "by reference" as you assemble and edit your project and is rendered in "real time" for previewing (which is why iMovie '08 has such high CPU speed requirements). No physical file is actually created until to share/export the file and at that time all of the various possible forms of content are rendered/converted to a single compression output format preprogrammed by the application or as selected by the user. It is very likely that the "reference movie" approach used by previous versions of iMovie had to be abandoned in order to make the process more universal for all source formats iMovie is now "theoretically" able to import. Think of the time base problems created when importing MPEG-2 camcorder content which has to have separate time bases and offsets for the video to synchronize it with AC3 audio which has been converted to AIFF. Now multiply this problem for each and every track simultaneously under the "playhead" at any given instant in the timeline. On the other hand, GarageBand does have a "Full Quality" option that allows you to export your video unchanged from when it was received by GarageBand and with either the original or AIFF (iDVD "ready") edited format to disk or to iDVD for the same automatic iDVD operations you formerly enjoyed with iMovie '06.
Example: when I want to create a DVD, I need to import/edit/export a movie in iMovie, then I need to import that movie file into iDVD (if I just open iDVD and load an iMovie project, iDVD crashes).
iDVD is not designed to handle iMovie "Projects." An iMovie "Project" is little more than a text file listing the particular ranges of audio and video source frames, text representing titles/instructions for displaying them, and a list of transitions also mapped to a combination of applied effects and a ranges of source audio and video frames to which they are applied, etc. while iDVD is only designed to handle physical audio/video compressed data.
This adds an additional step and it takes twice as long to render a movie (1/2hr clips takes 1 hr to render to file in iMovie, another hour to burn the movie to a DVD using iDVD). Clearly, this should be ONE step. If I want to index the movie, I have to import/export using Garageband, etc.
The "extra" step is required to transform the "text" description of the iMovie project into a physical audio/video file which iDVD can handle. In actuality, there is little time difference between iMovie '08 and previous versions. Previous versions of iMovie required you to wait while each non-editable file was converted as part of the import process. In addition, you had to wait while each title, transition, or special effect was rendered to a physical file during the editing process. What iMovie '08 actually does is consolidate all of this instances of waiting for the various conversions, rendering, and creation of various small files into the conversion and creation of a single long file where all of your waiting is consolidated into one long period rather than all of those old short ones. Stepwise, it was never done in "ONE step." As to the use of GarageBand as a separate application, I see little difference in using it separately for the chaptering and blending/mixing/synchronization of audio and video content and the use of iDVD as a separate application for the authoring and burning of DVDs. You don't hear many complaints about this being done in a separate application.
In addition with the degradation of the movie quality as discussed above, I think iMovie and iDVD are more toys than serious applications.
IMHO, if you elect to "play" with these applications and not use them as they were intended or to their full capacity, then "Yes," they are little more than toys.