Creating custom bokeh for lenses is something many of us try at some point. Even if it’s not something we’re ever going to do again, it’s fun to have a go at least once. We’ve mentioned the technique on the site a few times before. But, different lenses will render out of focus areas differently. The balls of blur will be difference sizes. So, how do you know what size hole to cut?
This video from the Kuldonov Brothers offers up a handy tip to get the size right. All you need is a compass. No, not the kind that’s built into your phone so your maps work. One for drawing circles. And it’s a pretty easy and straightforward process.
All you need to do is set your lens to its widest aperture and point it at your subject as you normally would. Then hold the compass up on the end of the lens on the same plane your cutout will be. Keep an eye on the liveview, and open up the compass until the points reach the width of the bokeh balls.
Then simply transfer this distance over to whatever you’re cutting your custom shape out of (or drawing it onto). You can either cut out of paper or card, or draw onto clear sheets of acetate, the choice is yours.
Whenever I’ve played around with this technique in the past, I’ve found it works better on some lenses than others due to the size of the design. Some lenses mean the design ends up too small to easily read, while others make it too big to include everything. This measuring method is great because you’re creating specifically for the lens you’re using. So, you can always get it looking exactly how you want.
You can also use this method to measure the size of custom shapes you want to make for use with the Bokeh Masters Kit.
Have you played around with custom shaped bokeh? Do you measure the size first? Or do you just make a best guess and see how it goes? Let us know in the comments.