by Rick Gerard Gerard Productions, Seattle, Washington, USA ©2001 by Rick Gerard. All rights are reserved. Used at CreativeCow.net by kind permission of the author.

ARTICLE FOCUS: Rick Gerard explores some methods of simulating a camera lens. In this tutorial, Rick uses the Boris Sphere Plug-In for After Effects.

Creating a fake iris using a 3D sphere plug-in like Boris Sphere or FE Sphere turned out to be a little more difficult than I thought.
The idea is simple, but illustrating a blade turned out to be a bit of a trick. Let's start there.


My first try didn't work out. It looks like this should work. It doesn't.





A little experimenting and I came up with this:

So why is this better? We will get to that later. Now on to the AE project.



Step 1: Creating the blades.

The first step is to create a long thin comp that will become your iris blades. I made mine 700 X 1400 pixels.
Now import in the blade illustration and move it to the far left of the comp so that its anchor point is at x=0 and y equals what ever you need to position the top of the illustration at the top of the comp. It should look like this:





Step 2: Now the fun part... or how I arrived at the shape of the illustration.

Set up another comp at your output resolution. I used 640 X 480. I called it 'Iris Effects'. Now drag the 'Blades' comp into this comp and apply your favorite sphere plug in. I used Boris Sphere. Set up the filter so that you're looking straight down on the sphere. Tumble @ 90°. Set the faces so the image wraps around and so you see only the front.

Here is the setup:



You'll notice that I've also added in the twirl filter with the radius set to 100 and the angle set to 2X + 0°. I couldn't get enough curve to the blade. This solved the problem.


Here's a little trick that will help you figure out what your illustration is doing. Drag the comps apart so you can see what's happening in the Iris comp as you modify the blades comp.






You'll see that you have one nicely curved iris blade in your Iris Effect comp. Move the 'Blade' layer up and down and you can see how this single blade will look. My first illustration was too narrow at the top. When I moved it down in the frame the iris blade took on a strange shape. If you don't like the shape of the blade go back to Illustrator and modify it. It only took three tries to come up with a blade shape that I liked. Just remember that the top edge of the shutter blade will be squished to a point by the sphere filter so you need to keep it fairly straight so you'll avoid having a star shape when the iris opens. Duplicate the blade illustration 10 times. Click on the top one and set its X position to 1400. Now select all and use the Align and Distribute palette to evenly distribute the 9 layers across your comp.






You'll have to move the top copy of the blade to the position 10 to make the blades look right. You should now see a nice closed iris in the Iris Effects comp. Now hit the letter P and set a key frame for each of the blades at 0:00.

Move to the 2 second point in the time line. Animate the Y position of the blades by selecting them all and using the shift and down arrow key. You'll see the effect as you look at the Iris Effect comp. It should look like this.



To add to the effect I also applied a key frame at frame one for the Spin in Boris Sphere of 30° and 0° at 2 seconds. This helped with the illusion.
A little hue and saturation adjustment and some modifications to the lighting settings in Boris sphere and I'm done.





Here's the final result.






-- See also Rick's other method of simulating a camera lens using Adobe Illustrator and Adobe After Effects. You decide which one you like best.



Rick Gerard is a frequent visitor and contributor to the Adobe After Effects COW. Pop in to comment on this article or ask questions. Like to see who Rick is and find other articles that he's contributed? Click here.

###