535 Tweening new layers across existing frames

- [Voiceover] In the previous movie, I showed you how you can use Photoshop to tween the positions of multiple layers in order to animate, in this case, the mechanical shutter of a high-end DSLR. It's a fairly basic effect, however, because we have a group of layers moving together, then an opacity transition for the strobe, and then another moving group of layers. So in other words, everything's happening independently. That is to say, there's no overlap. Compare that to this animation, where the two curtains of the shutter are both in motion, but they begin and end their movements at slightly different times.

And this helps to demonstrate a very fast shutter speed that goes beyond what's known as X-sync, meaning that the image sensor is never altogether exposed, all at once that is. And so, if we we were using a single-burst strobe, as is typical when shooting under water, we would end up with the band of light. In reality, you would probably be at the very top or the bottom of the fish, but you get the idea. Now, in order to create this animation, we need to tween new layers across existing frames.

And so, let me show you what that looks like. Here we are in that Photoshop file that we created in the previous movie. And so, if you're working along with me, make sure that your timeline panel is up on screen, which you can get from the window menu. And I'm gonna start things off with a couple of housekeeping chores. I'll begin by selecting frames one and two right here. And then deleting them, either by clicking on this little trash can icon, or if you want to bypass the warning, just press the alt key or the option key, and click.

And now notice that the shutter starts completely closed here in frame one, and it ends completely open here at frame fifteen. Now it's just gonna be confusing if we try to show the strobe at the same time. So, I'll select frame 16, which is when the strobe starts opening, and then I'll go ahead and shift click on the last frame, which is now 34, and then I will delete those frames by once again alt or option clicking on the trash icon, down here at the bottom of the timeline panel. All right, now we no longer need the shutter release or flash layers, so I'll select both of them here inside the layers panel, and then press the backspace key, or the delete key on the Mac.

All right, now we're gonna need two shutters moving at the same time. So I'll go ahead and rename this group First Curtain, let's say, and just to give myself a little more room, I'm gonna click this up arrow next to the FX icon, to tuck away those layer effects. And now I'm gonna create a copy of the very first frame, by pressing the alt key or the option key on the Mac, and dragging it to the very end of the timeline panel, so I have a new frame 16. Now if that doesn't quite work, the way it didn't for me, I obviously dropped the frame into the wrong location, then just go ahead and drag that guy to very end, like so.

I also don't want either of these guys to have any duration, so I'll just go ahead and shift click on frame 16 right here, and change both of them to no delay, like so. All right, now is where we have to pay pretty close attention to what we're doing. I'm gonna click on frame 16, to select it independently, and I'm gonna create a copy of this first curtain group, by pressing control J or command J on the Mac, and I'll go ahead and rename this guy Second Curtain. Now notice that that affects all of the frames, and that's because the position of the blades in the second curtain are all at the same location.

So we've gotta make a couple of changes here. First, turn off the second curtain for a moment. We're still just working on frame 16, by the way. And then twirl open the first curtain, so that we can move its blades out of the way, by clicking on the first blade, and shift clicking on the last blade, like so. Now we need to align these guys to a certain point, and to get to that point, go ahead and press the control key, or the command key on the Mac. And click the layer mask for either the first curtain or the second curtain group, doesn't matter, because they're both the same.

And then go up to the select menu and choose inverse in order to select the area outside the shutter release. And then, make sure your rectangular marquee tool is selected, and go ahead and press the shift and alt keys, that would be shift and option on the Mac, so that you see a little X next to your cursor. And then drag to find the intersection of these two areas right here. Just so that you have a point below the shutter. Now we want to align the blades to that point by selecting the move tool, and then click on this first alignment icon, align top edges, to move all those blades downward, so that they align to the top of the selection outline.

All right, now you can go ahead and twirl that guy closed, and press control D, or command D on the Mac, to deselect your artwork. All right, now I'll go ahead and turn this second curtain back on, so we can see the second curtain all the way down. And I'm gonna add a couple of frames that are gonna be duplicates of frame 16, by clicking on the page icon a couple of times, down here at the bottom of the timeline panel. All right, now what we want to do is figure out where this second curtain should be all the way raised, and that ought to be 13 frames over from frame 18.

So you may recall, in the previous movie, that we initially created 13 frames between frame one and between frame 15. And to demonstrate what I mean, I'm just gonna select all the frames, by clicking on frame one and shift clicking on frame 18 and turning off the second curtain group for just a moment. So that you can see, that at frame 15 right there, the image sensor is fully exposed, and at frame one, it's covered up. So what that tells us is that we have frames two through 14 that are transitional frames, and two through 14 is a total of 13 frames.

And so now we have to do the same math in order to figure out where things start for frame 18. So in other words, how many frames back is 13 frames from 18? So if you subtract 13 from 18 you get five. And then you have to move one farther back. And just take my word for it for now, but if you'd like you can count frames five through 17 and you would find that those add up to 13 frames. Anyway, so what I'm gonna do here is I'm going to go ahead and select all my frames once again, one through 18, and I'm gonna turn the second curtain group back on.

And then I'm gonna switch back over to frame four, and I'm gonna shift click on frame one as well. So frames one through four should be selected. And then what you wanna do is pretty much the same thing we did for the first curtain just a moment ago, that is, move the blades, but we're gonna move them to the top instead of the bottom. And so I'm gonna go ahead and twirl open this second curtain group, click on blade one there. Shift click on blade four, so all four of them are selected. And then, control or command click on the layer mask for that group.

Then, go up to the select menu, so I'm repeating the same steps, and choose inverse. And then I'll switch back to the rectangular marquee tool, and then press the shift and alt keys, that's shift and option on the Mac, and then create an intersection along the top edge this time around. Now switch back to the move tool, and then with those blades selected right there inside the layers panel, go ahead and click on the third icon in, the one that reads align bottom edges, in order to move all those blades upward.

Now it may not initially look right, but that's because we're seeing the first curtain blades down below here. All right, I'm gonna go ahead and press control D, or command D on the Mac, to deselect the image. And I just want you to see here, if we start at frame one, and just click our way through, we can see that the first curtain is going downward until we get to frame five, and that's because we haven't taken care of the second curtain frames at this point. So what we're gonna do is click on frame four, and then shift click on frame 18, and we're gonna tween between 'em.

And you can do that by clicking on the little tween icon down here at the bottom of the timeline panel. And that will do some tweening, but notice it's not quite what we're looking for. I'll go ahead and select my first frame, and I'll click the play button down here, and I want you to see, after the three-second delay that things start moving down. Did you see that? But we're exposing part of the image sensor in the background. Here we are in frame four, and then five, and then six, and so forth. And notice, as I click through these frames, that the distance between the two curtains in starting to get smaller and smaller and smaller until they pinch together.

And that is not the effect we want. We want that to distance to remain the same the entire time. And so we're gonna have to make a change here by going up to the edit menu and choosing step backward. That's gonna undo that tweening that we just did. And now, go ahead and click on frame four and then shift click on frame 18, and instead of clicking on the little tween icon down here at the bottom of the timeline panel, you wanna click on the flyout menu icon in the top right corner of this panel, and choose the tween dot dot dot command.

And what that does is it forces the display of the tween dialect box which we desperately need at this point. Make sure you're tweening with the selection, that means frames four through 18. And you can leave all the parameter checkboxes turned on. That really doesn't matter for our purposes. What we need to change is this guy right here. Instead of tweening all the layers, which is what we were doing a moment ago, we just wanna tween the selected layers which are these four blades in the second curtain group. At which point, click okay in order to make that change.

And now, if you click on the very first frame there, and then click on the play button, you'll see that that distance between the curtains remains the same the entire way down. And if you really want to prove it to yourself, then drop down to the word once at the bottom of the timeline panel. Click on it and choose forever. And then, go up to the file menu, choose export in the case of Photoshop CC, and choose save for web legacy. If you're working on an older version of the software, you can just choose save for web from the file menu.

At any rate, that'll bring up the save for web window, at which point make sure that you're saving to the GIF format, and that the transparency checkbox is turned off. That'll just go ahead and give you one extra color to work with. And then you can save out your animation if you like, or, in my case I'm gonna preview the effect in Chrome by clicking on a little preview icon right there. And then I'll just scroll down so we can see what's happening, and now you can see that we're getting exactly the effect we want. After a three-second delay, we have a continuous distance between those two curtains.

And that's how you tween the position of new layers inside existing frames when creating animations inside Photoshop.