Hi mford610,
Thanks for the file, I just got it, very much appreciated to clear this problem.
The file that you have send me shows exactly that problems. a very distinct pattern. Your project settings are set to 30 fps and the render settings to 24. There is your problem. Think of the project set up as 30 frames, whereby each frame hits the mark at 15º fo the zoetrope’s 24 images/windows. Think of 30 cards, that have that image shown precisely. Now take 24 cards and place them with equal distances from start to finish. Here is the pattern.
To fix this, go to your Project Settings (CMD+D) and set parameter to 24fps. Now the degree of your wheel is off. I would set it to zero degree on frame zero and 15º on frame one, as well as in linear as it is now. Then select the first keyframe in the F-curve editor and go to Function>Track After> Repeat offset. This will allow for one repeat. While the track (Null>) Rotation.B is selected in the F-Curve editor, go to the Attribute Manager, and set the repetition to any number that fits your project.
I hope you don’t mind my note: All of that works as the rendering takes the middle position of the frame and renders it. In the moment you introduce motion blur, things might work differently. The zoetrope works normally based on an darker outside while the image is mostly much brighter. So one’s eyes, get a flash and the after image will stay for a little bit longer than it takes to get to the next one, hence the fluid animation. With motion blur and a white outside that might be a little bit more difficult.
My best wishes for your project.