The latest project I took on was to figure out if I could create a lens for my Z-Mount Nikon Mirrorless cameras using a disposable camera lens. While there are many nostalgia-fueled filters that can mimic the look and feel of 90’s-era disposable cameras, I wanted to create that effect literally through the lens—but picked up by my Nikon mirrorless sensor.
I broke apart a Kodak Fun Saver disposable camera and removed the plastic lens that is included. Kodak has a patented 30mm f/10 lens consisting of two aspherical moulded plastic elements. The disposable camera uses a shutter speed of 1/100s and ISO800 film.
I was able to find a CAD model of the Nikon Z-Mount threading and I added to that model to essentially mimic the Z Sensor cap that comes with the camera. There are a ton of videos that show how you can drill a hole in a camera body cap and glue on the lens. But I wanted something more put together and permanent. In those tutorials, they list a hole size of 16mm so I used those measurements to add a hole to the model. This measurement is perfect. The lens snaps in very securely with this measurement.
It took many/ many iterations of this 3D print. This is due to finding the precise focal flange distance—the minimum distance necessary between the sensor and the lens. In my research people mentioned that if the focal flange distance is too close, it would be blurry but if it’s too long it will be infinity focus just cropped (like a tube that creates a macro effect). From my experience, this was not the case.
I made many, many models to try to nail down the focal flange distance perfectly. When it was too close, it was very blurry, but when it was too far it was also very blurry. I made the first one at 10mm which was around the standard thickness of the sensor cap. Then I went ahead to 40mm thinking the infinity focus would kick in. Also blurry. Then I went to 30mm and it was still too blurry. Then I went to 20mm and I made a mistake on the print making one of the walls too thin and it cracked when I pushed the lens in. But in the process, I knew I was close. So I upped it a bit and got it pretty close! Because there are no moving parts, in order for the shot to be in focus, that distance has to be exactly right. Or in my case, “right enough”. Inevitably the focal flange distance ended up being 22mm for me to be somewhat satisfied. Maybe in a future iteration, I will put a slider mechanism to push the lens closer and farther away from the sensor to really fine tune the focus. I think I can figure out a way to do that where there are no dangers of light leak between the two parts.
Take a look at a few samples I took this morning in downtown Raleigh with my Nikon ZF. At medium focal range things are somewhat sharp but there are aberrations and inconsistent focus all around. I may try to print a few more versions a few millimeters apart from this one just to see if I can get things even more sharp. But for now, it has tickled my nostalgia bone.
