Lock Durations After Added?

Question

Ok, I am a new Mac owner, and I must say that I love it. I previously had terrible fits with Windows Movie Maker. Crashes, transitions not working, freezing up, etc. IMovie is 100% better then WMM, but I am still running into a major problem. I am working on a rather big project, around 57 minutes long on WMM. The problem is on IMovie, I can't for the life of me get the durations to lock. I have the transition set to a 2sec duration automatically, those work fine. I have troubleshooted this problem for nearly 3 days now with no luck. When I add a picture, or a scrolling credit or something like that, it either adds sec. to previously added titles or clips, or subtracts them. Sometimes it will do this to some of my very first additions to the project which is now only 6 min long, but it is going to prove to be menacing as the project becomes longer. I hope there is just something I am missing that's right in front of my face. I really like IMovie, so if there is anyone who can help a Mac Noob it would be much appreciated.

Answer 1

When you add a transition, it takes half the length of the transition from the clip or still in front of the transition, and half the length of the transition from the clip or still after the transition. This means that a transition can be no longer than half the length of the shortest clip or still around it. For more details on how this works...
NTSC = 30 frames per second
PAL = 25 frames per second
I ran an experiment on NTSC, and here is how it works. First with stills, then with video clips.
First do the math in Frame mode.
NTSC clip 3:00>transition 1:00 >clip 3:00
convert to frames
clip 90 frames > transition 30 frames > clip 90 frames
This implies that originally you had stills that were 3:15 (=105 frAMES) long with no transitions.
Two clips each 105 frames long. Put a transition between of 30 frames. Divide by two to get 15 frames subtracted from each side. Now you have 3:00 (=90 frames), transition of 30 frames, next still of 90 frames. Total frames still equals 210.
Now change transition to 1:15 (=45 frames). Divide by 2 and round down = 22 frames subtracted from each side. Now you have still of 105-23 = 82 frames, transition of 44 frames, still of 82 frames. The overall total is still 210.
Now let's look at a different case. Delete the transition, and set the length of the photos with no transitions to 3:15 (105 frames).
Now, go into File/Project Properties/Timing, and put a check next to Photo Duration:Applies to all photos.
Now, the photos will stay the same even when you add transitions, but the project gets longer.
Original still of 105, still of 105 = 210
Insert transition of 30 frames
Now we have still of 105, transition of 30, still of 105, and the total = 240. The project got longer by 30 frames, but the photos kept their original length.
For Video, start with 2 clips of 4 seconds each (= 120 frames each)
Add 1 second transition. Clips are now 105 frames then 30 frame transistion. Total frames still 240.
Change transition to 45 frames. Clips are now 98 frames plus 44 second transition. Total frames still 240.
In iMovie 08 (version 7) you could select whether transitions for video would make the movie longer or would keep the same length. It was confusing, and when you make the movie longer, you pick up video frames that you had previously edited out, so the results were randomly bad. So I think in iMovie 09 (version 8), they decided that transitions for video would keep the total project length the same.
Another point...
50+ minutes is a very long movie for iMovie. If it is photos only it might work, but if it includes a lot of high-def video, it probably will not work. iMovie 09 has some great ease of use features and lets you see your edits in real time, but this becomes a constraint as the movie gets longer and virtual memory fills up. You may want to split your movie into shorter movies, or you may want to try Final Cut Express, which is fine for long movies (but harder to learn) because it has a more traditional architecture.