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 number 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 undertaking well-lit objects onto a wall or display screen in a darkish room. One of many distinctive traits of those lenses is their extraordinarily giant picture circle when used to seize gentle as an alternative of projecting it. On account of needing to seize scenes behind the lens, the picture circle these lenses undertaking is totally large. Within the case of this specific 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 share of the scene? Nicely, in Perks’ case, you create a customized gentle display screen utilizing a big piece of diffuser movie sandwiched between two items of plexiglass. Even in its primitive kind, it’s attainable to see the picture projected from the lens. However Perks takes it a step additional purchase constructing a wholly customized framed gentle display screen.
For the reason that display screen 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 facet, have a digital camera on the opposite facet, and seize the projected picture onto the picture projected onto the diffuser movie. Focus is finished by shifting one facet 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, at the least, it seemed prefer it was.
|An illustration shared by Perks displaying the fresnel lenses (inexperienced) sandwiching the diffusion panel to higher focus the sunshine from the lens to the digital camera.|
When wanting on the projected picture, Perks observed heavy vignetting that rendered the picture nearly unusable. To fight this vignetting Perks took classes from his DIY projector undertaking and positioned fresnel lenses on each side of the diffusion display screen to higher redirect the incoming gentle into the digital camera reverse of the episcope lens.
To cap all of it off, Perks added bellows created from folded black paper and a motorized focusing system with 3D printed elements and gears, in addition to some bearings and different parts.
|Should you thought nailing give attention to 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 beneath, the DIY lens has an extremely shallow depth of subject, 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 nearly has a tilt-shift-like impact, making the topics seem as if they’re miniature fashions as an alternative of actual life.
|Screenshot from video captured with the Canon R5 with a 35mm F1.8 lens hooked up.||Screenshot from video captured with the Canon R5 with a 35mm F1.8 lens hooked up, however by way of the DIY lens Perks constructed.|
It’s a particular look that you simply gained’t get with even the quickest primes on a full-frame digital camera. The truth is, this lens has a crop issue of 0.08, that means the 432mm F5 episcope lens is roughly equal in subject of view and depth-of-field as a 35mm F0.4 lens.
|A comparability picture displaying what the DIY lens appears to be like 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 value? All the rig, together with the 3D printed half and lens, value 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. Certain, you’ll want the know-how and time to create this monstrous lens, however when it’s all stated and performed, you’ll be capable to say you have got probably the most uncommon digital camera lenses on the market, and have the pictures and video to show it.