The Science of Custom Bokeh...?

I have done a project for university using shots where I have created my own "bokeh" (not sure what term to use but I have altered the traditional out of focus circle from a light source).

NOT MY IMAGE but this is an example of changing the traditional out of focus circles:


I have done this in my video but I was wondering if you could help me look at the actual science behind this effect so I can add a part to my presentation of how this effect actually works and why.

If anyone has any information as how to refer to this effect as well it would be helpful as it is not particularly well written up online so I don't know how to refer to it.

I made my masks not as images but as words so there were gaps between the letters almost making the "filter" act as a diffraction grating. Not too sure how to explain this in so many words though.

Thanks

 

My aren't images but are video and I am away from the computer. When I get back to my laptop tonight I will upload a freeze frame.

 

Being a student on a low budget I made my own cardboard kit which I was able to pop under a UV filter that I attached to a Canon 85mm f1.2 which I rented from the university.

I've uploaded an image which should hopefully demonstrate the similarity between the diffraction filter and my image.

This image is a screenshot and therefore not an actual indication of the quality of my work! I don't think the freeze frame does the short piece justice!

I think I need to find more information on the physics of lenses and how the aperture shape influences the shape of the bokeh as through the make shift kit I am altering the shape of the aperture.

 

These are perfect! Now I have the search tools I need to be able to research the topic further. Previously I was a bit stuck as I knew what I wanted to find but I didn't know what terms to exactly search for!

The circle of confusion is particularly useful and will be very helpful to my project! Thanks for your help.