The ProShow Blog

Tips, tutorials & inspiration for making slideshows

A Simple Introduction to Modifiers

Today’s post comes from Dale Fenimore, a photographer and slideshow guru who runs Fenimore’s PhotoVideo Productions. Dale produces training, slide styles and transitions for ProShow users. Check out his site to learn more.

What is a Modifier?
Modifiers are a wonderful tool that let you do things in ProShow Producer that are otherwise difficult. Many people hardly even know this feature exists but with the appropriate guidance anyone can use a modifier to automate a simple task.

First, let’s get a little into what a modifier is. A modifier is composed of one or more actions. Each is composed of any one of three different things: a constant numerical value, a variable amount that’s based on a feature in use by an existing layer (for example, Pan-X or Opacity), or a mathematical function (such as cosine or sine).

Pan Following Modifier Example

Let’s create a simple ‘Pan Following’ example to see how modifiers work. This effect will align one layer’s center with another layer’s center, causing it to follow that layer’s center wherever it goes.

  1. On a blank slide, add a gradient layer and make it all white (select presets: simple, type: linear, click on a color combination from the sample choices that has white on one side, click the white color marker located under the Colors section and drag it to the right, on top of the other color marker).
  2. Make its dimensions 1200×800. Click on OK. Set its scale to Fill Frame and change the zoom-x and zoom-y to 30% for all keyframes.
  3. Next, add an image in layer 2. Set its scale to Fill Frame.
  4. Now, let’s define layer 1’s path. Add two keyframes to layer 1’s default two so you have a total of four keyframes. Set keyframe 1’s pan values to -35, -32; keyframe 2’s pan values to -35, 32; keyframe 3’s pan values to 35, 32; and keyframe 4’s pan values to 35, -32.

  5. To start the process of making the image layer follow the white layer, select layer 2.
  6. With the cursor hovering over the Pan-X box of either keyframe, right click and select “Add Modifier.”
  7. Set “Variable Amount Based On” to Pan-X. Set “From” to Layer 1. Click OK. With the cursor hovering over one of the Pan-Y boxes, right click and select “Add Modifier.” Set “Apply To” to “All Keyframes.” Set “Variable Amount Based On” to Pan-Y. Set “From” to Layer 1. “Multiplied by” should remain at 1. Click OK.

Layer 2’s pan-x and pan-y boxes should now each contain a little red triangle in the upper right corner. Make sure the image layer pan values are set to 0 for both keyframes.

Play the slide. You should see the white layer and the image layer moving together, one on top of the other from start to finish. The white layer should be positioned exactly in the center of the image layer. This shows that layer 2’s center is following layer 1’s center.

Try another little experiment.

Change layer 2’s Pan-X values from 0 to 35 for both keyframes. Play the slide again. Notice the white layer’s position compared with the image layer’s. The image layer’s left edge is aligned with the white layer’s left edge as they move around the screen. Also, the white layer is in the image layer’s vertical center (halfway between the top and bottom).

Try this next: Change layer 2’s Pan-Y values from 0 to 32 for both keyframes. When the slide is played, notice that the white layer and the image’s upper left corner (the part that is in the visible portion of the screen) move together. Note that the mask layer does not cover the part of the image extending beyond the upper screen frame.

Now, one last experiment.

Make layer 1 a mask: Go to Slide Options | Layers | Layer Settings. Under the Mask Layer section, set Mask Type: Intensity (Grayscale) and Mask Depth: 1. Play the slide again. An image layer section the same size as the mask layer moves around the screen. This is the image portion that was offset from the mask center. Note: Since the white layer is now a mask, you no longer see it separately from the image. You should see only the portion of the image immediately below the mask layer.

Note on the pan settings used above: The white layer pan settings were not arbitrarily chosen. The full height of a 1200×800 layer with a 30% zoom that has been scaled to Fill Frame is 35.56. Half of the layer (17.78%) is above horizontal center. The distance the white layer’s center needs to move to put its top edge against the frame’s top edge is 50% – 17.78% = 32.22%. Hence, the rounded off Pan-Y value of 32 used above. The white layer’s full width is 30.00, which means 15% of it is to the left of vertical screen center. Thus, 50% – 15% = 35% is the distance the white layer’s center needs to move left to put its left edge against the frame’s left edge. Therefore, the reason for the Pan-X value used above. For a more in-depth explanation of how I arrived at the layer’s height and width, visit my blog or read this article.


1) You just used two simple modifiers to make one layer follow another layer exactly. You learned that a layer center follows a layer center in a pan-following modifier. In the process, you learned how to offset the center of the layer doing the following from the center of the layer being followed.

2) You also learned how to show any portion of an image underneath a smaller mask layer, even if the mask moves. In essence, this lets you select only the desired portion of an image for presentation.

Why would you want to do this? Maybe you want to highlight one person in your image and exclude everything else. Possibly you want to move that image’s masked portion away from its default screen location, perhaps to accompany other such images and/or to better position it for captions.

There are many situations where this might be a useful technique to know. You might change the opacity of several other layers by only changing the opacity of one. You could cause several layers to rotate by changing the rotation of only a single layer. You may not need this technique often, but it’s handy to know for those times when you do need it!

3) I also provided a tip for quickly creating a solid color layer using a gradient layer. This could prove useful if you find your single color layer needs multiple colors and all of its existing keyframes. Had you used a solid color layer, you would have needed to recreate the entire layer (size, keyframes, and all associated keyframe settings) using a gradient layer. It’s possible to convert a single color gradient layer to a multiple color gradient layer (and vice versa), but you cannot change a solid color layer to a multicolor layer.

There you have it. Lots of good stuff in a quick tutorial!

-Dale Fenimore

Want to learn more about modifiers? Check out our training DVD all about using modifiers in ProShow Producer.



