By Arild Båsmo, founder of VALOI
The light source in the original easy35 worked really well. It got thousands of people scanning film with results they were genuinely happy with. But there was a number we could never quite make peace with: 81%.
81% Uniformity
That was the light uniformity with a 55mm lens on a full-frame camera — meaning the corners of the illuminated area received about 81% as much light as the center.
For most subjects, that's fine. For thin color negatives, images with low contrast, under or overexposed images, it necessitated post-processing.
Color negative film is inherently low contrast. When you stretch that contrast in post to get a natural-looking image, you stretch everything equally — including any unevenness in the light. A subtle falloff in light intensity, invisible to the naked eye, becomes visible. Slightly underlit corners become a problem on your most challenging frames, and this bothered us.
The conventional fix is to make the light source bigger, because that moves the effective "corner" of the light source out. It works, but also makes the device larger, heavier, and more expensive. For the easy35, we weren't willing to do that.
The Integrating Dome — Patent Pending
We tested a bunch of options, looking at direct diffusion stacks and side-diffusion options, reflectors and moving the film closer to the light. None of them did what we wanted within the target footprint.
So we had to go and invent a new configuration. The solution we landed on was inspired by scientific instrumentation: the integrating sphere. Scientists use full spheres to measure total light output from a source with near-perfect uniformity. Fitting that into a device for scanning is impractical because of size. Instead, we adapted the principle into a half-sphere — an integrating dome.
The idea is counterintuitive. The LEDs in the easy35 v2 don't shine at the film. They shine away from it, down into the dome. The dome's interior is a matte, specially chosen white plastic — highly reflective and highly diffusing. Light bounces and scatters inside the cavity, mixing thoroughly before it exits back upward through an aperture towards the film.
By the time light leaves the dome, it has undergone so many reflections that it has no "memory" of where it came from. The dome shape ensures optimal scattering and that the center is as well lit as the edges. The result is illumination that is almost perfectly uniform across the entire aperture.
99% Uniformity
The numbers bear this out. Our v2 achieves 99% light uniformity — measured the same way as the 81% figure, as corner brightness relative to center brightness. That's not a modest improvement. It's a 15× reduction in non-uniformity.
In fact, we’re so happy with it that we decided to file for a patent for the idea. It’s now a light source with a pending patent, and we couldn’t be more proud.
Why It Also Works With Wide-Angle Lenses
A flat diffuser panel has edges — physical sidewalls that cast shadows when you use a wide-angle lens with a wide imaging cone. The dome has no sidewalls in the optical path. Because the illuminator is curved and recessed, wide-angle lenses can get close to the film plane without encountering any vignetting from the light source geometry. The v2 has been tested with lenses down to 30mm on full-frame — something that simply wasn't possible with the original design or any other compact scanning device with a sufficiently long distance from film to illumination front surface to blur out dust.
The Light Itself
Uniformity is, of course, only part of the story. The color of the light matters too, especially for color film. The easy35 v2 uses 95+ CRI LEDs tuned to a color temperature that naturally counteracts the heavy orange mask of color negative film. It's further adjusted by a carefully chosen reflector color. This isn't just about aesthetics — it's about preserving the full color spectrum in your memories. A well-matched color temperature reduces the noise in the red channel when all channels are properly exposed, which means more information recovered and cleaner images, even with older cameras.
The dome takes up space. The v2 unit 16mm taller and about 2mm wider in both directions. 90×90×90mm. We’re very proud of how much we managed to put into that space, in exchange for the optical performance gain. Everything else we did — moving to injection-molded ABS, the all-metal rotation mechanism, the larger battery — are all stories in themselves.
The easy35 v2's light source isn't an incremental improvement. It's a fundamentally different approach to the same problem — one that lets us put near-perfect uniformity into a device that still fits in a jacket pocket. We just had to invent it first, then design the electronics in-house and manufacture our own light source.
If you enjoyed reading this article, you might enjoy reading about the mechanical design of the easy35 v2 and why it has five spring loaded ball bearings in it.
Illustration photos
A prototype of the light source we developed for the easy35 v2.
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