This Photographer Made an 80mm f/0.5 Lens for His Sony Camera

Apr 07, 2025

Kate Garibaldi

An Italian photographer frustrated with low-light image quality took matters into his own hands by building an 80mm f/0.5 lens for his Sony mirrorless camera.

PetaPixel has previously covered mind-boggling low aperture devices such as the F-Zero Camera as well as the “Impossible Lens,” a Leitz projector lens that was rebuilt into an f/0.3 29mm. The latest homemade lens to push the boundaries of what seems possible is an 80 mm f/0.5.

This super wide aperture lens was made by Rulof, an Italian entrepreneur and inventor who shares his creations via his YouTube channel “Rulof is How To Make.” In his newest video, spotted by Hackaday, the mononymous Rulof shares his inspiration and journey in creating this inconceivable lens.

A paper model of a large camera lens mounted on a rotating display stand, with a smaller lens placed beside it. The background is a blurred gray wall, giving focus to the model.

He embarked on a journey to create this lens mainly due to issues with low light performance from lenses currently in the market. Nothing exists like this. So Rulof decided to make it himself.

To create it, Rulof purchased cinema projection lenses. He demonstrates how much larger the projection lenses are, almost a dinner plate in diameter, than a standard camera lens.

To apply such a large projection lens to a camera requires a diaphragm just as large. With nothing like this readily available, he instead found an adjustable circular drawing tool on Amazon. Made by Candeon, the stainless steel tool uses an adjustable rimometer to increase or decrease the scope. So much like a camera’s diaphragm, the device was perfect for creating his lens, even though it was not intended for this purpose.

A person holding an antique aperture blade mechanism from a vintage camera with both hands. The mechanism displays multiple overlapping metal blades and a central circular opening. The individual is wearing a blue denim shirt.

He used an industrial vise and car jack to measure the lens for precise adjustments, moving the friends up and down to discover the focus point. This allowed him to get an idea of the overall size of the lens housing as well as the focus ring. He projected his logo through the lens onto a whiteboard and moved the lens up and down until the projected image was in focus. By measuring that height, he was able to bring the numbers into Fusion 360’s design software to create a 3D printable housing.

After about eight hours of printing, adding some screws, and applying glue, Rudolph combined his components and brought his 80mm f/0.5 lens to life. No homemade lens is complete without a homemade tripod head, which he also 3D printed specially designed to hold the gigantic lens.

A 3D modeling software screenshot showing a cylindrical object with two colored planes intersecting it. The interface includes various tool options and menus at the top. The design appears to be in a drafting or editing stage.

A close-up of a 3D printer in action. The printer head is moving over a partially completed circular design. The printer is labeled with "Ender" and the image shows intricate wiring and mechanical parts.

A person applies glue from a yellow and red tube onto a metal component placed on a cylindrical black base. Another circular component is held in the other hand, possibly for assembly. The setting is on a wooden surface.

A person is assembling a black, cone-shaped device, using screws to attach parts. The device is on a table, and the person's hands are making adjustments. They are wearing a dark sweater, and a blue tool is partially visible on the table.

A man with a beard is adjusting a large black camera or piece of equipment mounted on a stand in a workshop. He is wearing a green jacket and protective eyewear pushed onto his head. The background is an industrial setting with tools and machinery.

So, did it work? Absolutely. Although Rulof admits that the lens is not super sharp.

“I know it isn’t really a very sharp lens, but overall considering that I just built it by myself, it’s working. I have a very messed up blurry background, which is something that I love,” Rulof explained.

A smiling person with curly hair and a beard, wearing a light green jacket. The background is dark and blurred, with some out-of-focus lights visible.