Dulens APO Mini Prime Series
The Dulens APO mini prime series is designed for cinematographers seeking the coveted vintage low-contrast aesthetic with pronounced flares, while rejecting the uncorrected characteristics of vintage primes that lead to chromatic aberrations. These mini primes sport a cinema housing with a non-extending or rotating front, along with a lengthy, smooth focus throw devoid of backlash, making them an ideal choice for high-end productions. With their compact size and lightweight build, the Dulens mini primes, the smallest large-format cine primes available, cater excellently to small-scale productions and those employing drones, gimbals, and other setups necessitating a diminutive and lightweight camera configuration.
All the Dulens mini primes boast an ample image circle, comfortably accommodating a range of large-format cameras, including the Red Monstro and Arri LF. The 58mm and 85mm variants even cover the ARRI Alexa 65.
Apochromatic Design (APO)
The term ‘APO’ refers to apochromatic, a lens design offering superior correction of chromatic and spherical aberrations compared to the more common achromatic lenses. Unlike many modern lenses, the APO standard in Dulens APO mini primes is not achieved through the use of aspherical elements, but rather through an intricate lens design aimed at minimizing chromatic aberrations. Aspherical elements come with certain drawbacks, notably the much-maligned “onion bokeh,” stemming from CNC molding used in aspherical manufacturing. Dulens presents a well-defined and clean bokeh, with a high iris blade count ensuring the bokeh remains consistently circular even when stopping down the lens to values like t5.6 or t8.0. Thanks to the non-aspherical lens design, undesirable bokeh textures like onion rings are wholly absent.
Currently, the Dulens APO mini prime series includes focal lengths of 31mm, 43mm, 58mm, and 85mm. Dulens is actively developing more focal lengths, with the imminent introduction of a 21mm lens. The brand’s research also extends to even wider and longer focal lengths, guided by the same design philosophy. All optics in the Dulens APO mini primes series are original designs, not mere reiterations of vintage optics. While inspired by classic designs, they’ve been recalculated using modern methods to both reduce chromatic aberrations and achieve high MTF (contrast and resolution). A noteworthy feature of this lens series is the ability to seamlessly intercut lenses, ensuring consistent contrast, color, and flare properties across the board.
The 85mm lens consists of 7 elements in 6 groups, the 58mm variant features 9 elements in 8 groups (double-Gauss), the 43mm version comprises 10 elements in 8 groups, and the 31mm lens employs an advanced retrofocus optical scheme.
Dulens employs a novel coating named “V or VL” coating on its lens structures. Recognizing that some cinematographers favor non-coated lenses for their distinct flare and fog/bloom attributes, Dulens strikes a balance. The “V coating” aims to offer a signature-style flare and low contrast, without compromising light transmission as observed with white glass or non-coated lenses. The resulting lens flares from this coating exhibit a playful quality, diverging from the conventional fixed-color flares produced by most modern high-transmission coatings. Instead, the Dulens flares display ring-shaped patterns and rainbow hues, lending unique character to each shot.
Interchangeable Lens Mount
At Gafpa, we ensure proper collimation for all lenses. However, slight deviations may occur due to an inaccurately collimated camera mount or an optical low-pass filter (OLPF) that virtually alters the backfocus of wider lenses. To address this, we provide a tutorial. With a simple lens spanner, users can open the lens from the front. Using a straightforward system controlled by a screwdriver, you can establish infinity focus by aligning the lens with the infinity mark and adjusting accordingly. While the lenses come with a PL mount, EF mounts are also available in our shop and can be user-replaced in under 2 minutes.
Lens Markings and Focus Gears
The Dulens APO Mini Prime series is equipped with all-metal 0.8-pitch focus gears for both the iris and focus control. Despite their compact size, concerns about motorized iris control are unwarranted. Extensive testing across various scenarios has demonstrated that, as long as two rods (one on each side) are used, these lenses can be motor-driven via follow focus systems. We even examined the compatibility of LPL to PL mounts on the Alexa, and no motor obstruction issues were found.
When ordering the Dulens APO mini prime, there’s no need to specify whether you prefer lens markings in feet or metric units. Both metric and imperial markings are currently displayed on the lens.