Matthew Perks, creator of the DIY Perks YouTube channel has shared how he constructed a ‘35mm F0.4’ equal lens constructed round an episcope lens taken from a few of the earliest projection know-how.
As Perks explains within the video’s introduction, the episcope lens was the optical ingredient utilized in epidioscopes to venture well-lit objects onto a wall or display in a darkish room. One of many distinctive traits of those lenses is their extraordinarily giant picture circle when used to seize mild as a substitute of projecting it. On account of needing to seize scenes behind the lens, the picture circle these lenses venture is completely large. Within the case of this explicit lens, Perks says the picture circle is an insane 500mm in diameter.
So, how do you make use of this half-meter picture circle when even medium format cameras would wrestle to seize a small proportion of the scene? Nicely, in Perks’ case, you create a customized mild display utilizing a big piece of diffuser movie sandwiched between two items of plexiglass. Even in its primitive type, it’s attainable to see the picture projected from the lens. However Perks takes it a step additional purchase constructing a wholly customized framed mild display.
For the reason that display would lack distinction with out being enclosed, Perks makes use of flocked items of aluminum to construct out the body of what’s successfully the lens’ physique. He then makes one other body and successfully mirrors it so he can then mount the lens on one aspect, have a digital camera on the opposite aspect, and seize the projected picture onto the picture projected onto the diffuser movie. Focus is finished by transferring one aspect of the rig ahead and backwards on a set of metal rods by way of linear bearings. With this in place, the rig was accomplished and able to roll. Or, not less than, it seemed prefer it was.
|An illustration shared by Perks exhibiting the fresnel lenses (inexperienced) sandwiching the diffusion panel to raised focus the sunshine from the lens to the digital camera.|
When trying on the projected picture, Perks observed heavy vignetting that rendered the picture virtually unusable. To fight this vignetting Perks took classes from his DIY projector venture and positioned fresnel lenses on each side of the diffusion display to raised redirect the incoming mild into the digital camera reverse of the episcope lens.
To cap all of it off, Perks added bellows produced from folded black paper and a motorized focusing system with 3D printed components and gears, in addition to some bearings and different parts.
|In case you thought nailing deal with an F1.2 lens was difficult, this lens will make that look simple by comparability.|
With all of that full, it was time to try the outcomes. As seen from the comparability pictures under, the DIY lens has an extremely shallow depth of area, giving a glance much like what you’d count on from giant format cameras or utilizing one thing just like the Brenizer Methodology. In some scenes, it virtually has a tilt-shift-like impact, making the topics seem as if they’re miniature fashions as a substitute of actual life.
|Screenshot from video captured with the Canon R5 with a 35mm F1.8 lens connected.||Screenshot from video captured with the Canon R5 with a 35mm F1.8 lens connected, however by the DIY lens Perks constructed.|
It’s a particular look that you just gained’t get with even the quickest primes on a full-frame digital camera. In actual fact, this lens has a crop issue of 0.08, which means the 432mm F5 episcope lens is roughly equal in area of view and depth-of-field as a 35mm F0.4 lens.
|A comparability picture exhibiting what the DIY lens seems to be like in comparison with a 35mm F1.8 lens on a full-frame digital camera in addition to a smartphone digital camera.|
So, how a lot did all of this price? The complete rig, together with the 3D printed half and lens, price solely $190 in supplies: roughly $200K lower than the Carl Zeiss 50mm F0.7 (the quickest lens ever produced) went for within the final public sale it offered in. Positive, you’ll want the know-how and time to create this monstrous lens, however when it’s all stated and executed, you’ll have the ability to say you may have one of the uncommon digital camera lenses on the market, and have the pictures and video to show it.