but as soon as clips are moved to the Time Line they loose about 10% of their height.
Hmm. I have never seen that kind of behaviour (different aspect ratio in the Clips pane vs in the Timeline) with PAL or with my limited NTSC experience.
This can be verified by duplicating the frame of a clip in the clips Pane as a "Still Frame"
This creates a 720x480 1-frame rectangular pixel DV clip to the iMovie's Media folder, which is the correct thing to do.
exporting it to the Desktop as a .jpeg picture.
Now, here iMovie converts rectangular pixels to square so it scales the image to 720x528, which is OK. I would scale it to 656x480 but the aspect ratio is the same anyway. (Maybe Apple wants to save the still images to a resolution which doesn't have to be upsampled in any direction when re-importing it back to iMovie (656x480 must be upsampled to 720x480).
Since (720 : 4) x 3 = 540 , there are only 12 pixels difference from true 4:3 (they seem to get lost in conversion to .jpeg)
A correct conversion requires scaling.
It is not common knowledge that the actual active NTSC DV picture size is as weird as 710.85x486 and the pixel aspect ratio in THAT is 4320/4739. And (710.85x486)x(4320/4739) = 4:3. Exactly! THAT is the 4:3 ratio on a TV!!
iMovie 5 and 6 do this complex thing right.
Now if we go back to iMovie 05, drag the same clip into the time line, select it to see it in the Editing Window of iMovie, where it can be seen with the distortion already having occurred. This distortion could be described as horizontal stretching or vertical squeezing.
Hmm. I don't see any distortion.
To find out find out how much distortion and where it is, go to “Edit/Create Still Frame” and a still frame of the distorted clip is added to the end of the Time Line. Drag it from there to the Clips Pane, and from the clips Pane to the Desktop. Click on it, and it will open with Quicktime Player. Then go to “QuickTime Player/View/Actual Size”, and then to “QuickTime Player/Window/Show Movie Info” and it will display 720 x 480 as “Normal Size” as well as “Actual Size”.
Yes, it uses 720x480 rectangular pixels because it is a 1-frame video clip, not a still frame. I would expect iMovie to behave like this.
In other words the picture has been flattened vertically so much, that its 540 pixel height taken by the camera has been reduced to 480 pixels, which is a loss of 60 pixels from its actual vertical camera taken picture height, and the original 4:3 ratio has been changed by this defective software to a 3:2 ratio. This is a loss of more than 10% of the height of the picture.
Now you are comparing rectangular pixels to square pixels.
When both the Preview .jpeg and iMovie clip.dv are opened side by side on the Desktop, and compared, there appears to be nothing missing or clipped off at either the top or bottom of either picture, which is proof that the iMovie in the derived .dv pic has been vertically distorted by the new iMovie software, squeezing the height of the picture approximately 10%, and whoever walks around in the film looks dwarfed and distorted as if reflected in a fun house mirror.
That's the way rectangular pixels look on a computer monitor. BTW, iMovie scales the rectangular pixel video behind the scenes to square pixels in its display window.
Having an old version iMovie 2.1.2 on my System 9.2.2, I then tried the same procedure with it, in the same manner, except that I got the actual pixel info by opening the still and the jpeg with Adobe Photoshop. They both returned 640 x 480 pixels a true 4:3 ratio.
iMovie 1-4 were sloppier than iMovie 5-6 with their pixel handling. Fortunately the error was small so it usually goes unnoticed.
I have bashed iMovie and Apple with other stuff but I don't see a problem with this particular issue. Infact, I'm surprised how well iMovie 5 and 6 work with this.
I just got iMovie 6 and the first impressions are OK: It feels almost as robust as iMovie 1.0.2 and iMovie 2.1.2 😉
p.s. I don't mean to offend you in any way. I'm just trying to prove my point. The video world is full of strange gotchas which may puzzle the user, especially when the applications automatically handle some obscure stuff behind the scenes. Usually you can trust the applications but I always verify the critical parts with every major upgrade.
