Using Premiere Elements 10* Windows, the focus is going to be on side by side (no gap between) clips and the last frame of the first clip up against the first frame of the second clip. The goal is to try to explain what is going on when placing a video transition to make a gradual, rather than abrupt, transition from one clip to the next. Extra frames needed to get the transition to work are often obtained from trimming video clips in the Preview Windows with its Set In Set Out points or trimming the video clip with the Split Clip Tool (aka Scissors Tool).
That does sound a bit strange trimming a clip to get extra frames for the transition to use, but explanation coming any minute. By contrast, for getting extra frames for stills we would think about just increasing the still default duration in preferences or dragging out the still on the Timeline with the Selection Tool. All this so that the handles have enough frames to make the transition.
What are handles? Handles can be thought of as the number of frames at the end first clip and the number of frames at beginning of the second clip that are needed to make the transition work. Sometimes these handles can be made up of the video clip's original frames OR frame repeats of the end frame of the first clip and frame repeats of the first frame of the second clip OR extra frames from beforehand trimming of the clip (Preview Window Set In Set Out Points or with Scissors Tool.) Best we build the foundation for Premiere Elements transition/clip handles and such from the following examples of trimmed, untrimmed/video or still clip.
VIDEO CLIP HANDLES EXPLAINED BY EXAMPLES
Let us say that we have a video clip composed of A, B, and C. If we try to shorten or increase its length on the Timeline using the Selection Tool, we cannot. If we use the Time Stretch, we can shorten or increase its length but we end up with fast or slow motion as the program subtracts or adds frames along the whole length of the clip. To the contrary, if we trim the clip in the Preview Window with the Set In Set Out points or use the Scissors Tool to obtain a trim consisting of only B, the file B on the Timeline can be dragged out with the Selection Tool to recover A and C, displaying our whole file again with its A, B, and C intact.
When B was on the Timeline, A and C were not really cut out. They were really still there, but they were not visible until we dragged them out with the Selection Tool. So, when we see someone saying that the transition is using frames from a trimmed clip, those frames could be, in this example, the frames from A or C, whichever end is involved in the transition with the next clip.
In the case of the untrimmed video clip, the first frame at its beginning is its first and the last frame at its end is its last. In this instance, we might be talking about extra frames in terms of repeats/copies of the first or last frame of that clip in lieu of "frames from trimmed clips" to make the transition. You can actually tell whether a transition is using frame copies/repeats versus trimmed clips to make the transition by viewing its display in the Edit Transition/Show Timeline section*.
All sorts of possibilities exist in transition duration and alignment and whether or not the transition will work, depending on the nature of the end of the first clip and the beginning of the second clip. Your attention gets drawn to this type of situation when you find that you want to align a transition Center at Cut and the transition will place only Start at Cut or End at Cut. The cut representing the junction of the first and second clip involved in the transition. In some instances where you cannot align the transition as wanted on the Timeline, you might be able to force the placement by going to Edit Transitions/Alignment and set the alignment there if it is not grayed out*.
UNTRIMMED/TRIMMED CLIPS - TRANSITION ALIGNMENT GUIDELINES AS FOUND IN ADOBE HELP
TWO TRIMMED CLIPS
If both clips contained trimmed frames at the cut, you can center the transition over the cut or align it on either side of the cut so that it either starts or ends at the cut. See Figure 1. A clip that has not been trimmed has a rounded edge in the upper-right corner of the clip. See Figure 1a.
|Figure 1. View of Timeline, Edit Transition Area with its Show Timeline section when dealing with both video clips containing trimmed frames at cut.|
|Figure 1a. Rounded Edge in the upper right corner of the clip seen when dealing with a trimmed video clip.|
TWO UNTRIMMED CLIPS
If neither clip contains trimmed frames, the transition autoamtically centers over the cut and repeats the last frame of the first clip and the first frame of the second clip to fill the transition. (Diagonal bars appear on transitions that use repeated frames.) See Figure 2.
|Figure 2. View of Timeline, Edit Transition Area with its Show Timeline section when dealing with both video clips that do not have trimmed frames at the cut.|
FIRST CLIP TRIMMED, SECOND UNTRIMMED
If only the first clip contains trimmed frames, the transition automatically snaps to the In point of the next clip. In this scenario, the first clip's trimmed frames are used for the transition, and frames are not repeated in the second clip. See Figure 3.
|Figure 3. View of Timeline, Edit Transition Area with its Show Timeline section when dealing with first video clip trimmed and second video clip not trimmed at end of the first video clip and the beginning of the second video clip respectively.|
SECOND CLIP TRIMMED, FIRST UNTRIMMED
If only the second clip contains trimmed frames, then the transition snaps to the Out point of the first clip. In this scenario,the second clip's trimmed frames are used for the transition, and frames are not repeated in the first clip. See Figure 4.
|Figure 4. View of Timeline, Edit Transition Area with its Show Timeline section when dealing with second video clip trimmed and first video clip not trimmed at the end of the first video clip and the beginning of the second video clip respectively.|
* Premiere Elements 10 on Windows 7 64 bit (NTSC DV Standard project) was used in this study, and the principles presented are applicable as well to version 4, 7, 8.0/8.0.1, 9.0/9.0.1, and 11. However, for version 11, the Show Timeline section is gone. And, new to Premiere Elements 11 is the Transition Adjustments pop up which contains the old options for transition duration in seconds and frames and alignment for Left Clip (formerly Start at Cut), Between Clips (formerly Center at Cut), and Right clip (formerly End at Cut). A More button is used to access the rest of the pop up which contains the Play transition option and adjustment of the Start/End points of the transition. See Figure 5 and 6.
|Figure 5. Premiere Elements 11 Transition Adjustments Pop Up when Transition is placed. Before More Button Options. No Show Timeline section|
|Figure 6. Premiere Elements 11 Transition Adjustments Pop Up when Transition is placed. More Button Options shown.|
For Two Trimmed Clip, opens on "Between Clips"
For Two Untrimmed Clips, opens on "Between Clips"
For First Trimmed Clip and Second Untrimmed Clips, opens on "Right Clip"
For Second Trimmed Clip and First Untrimmed Clips, opens on "Left Clip"
**Serious problems have surfaced regarding Premiere Elements 11 and its handling of audio transitions and new Transition Adjustments Pop Up. A new blog post will be devoted to this matter.