Use Case:

# Cross-polarized Photography

Reflectionless photography: the magic behind surfaces’ backside-illumination with Relio²

Here we provide a practical guide on how to set-up your Relio² lights to achieve cross-polarization, the “holy-grail” of reflectionless photography.

Direct, indirect lighting and the less-known "backside-illumination"

Reflectionless photography is very sought-after, especially when filming documentaries. The best known and most traditional solution is to diffuse the light source in order to reduce its luminance. This translates into umbrellas, diffusers, flags and other bulky equipment.
There’s a technically advanced and little-known solution, which solves the problem at its root: it’s called "backside illumination".
A linearly polarized light is acquired by a camera sensor whose optics are polarized as-well, but rotated by 90º compared light’s polarization.
What happens? Direct light is completely blocked, and the camera sensor catches only the light that penetrates inside objects' porous surfaces. In this process, the light gains color and gets de-polarized.

The final result

You'll be able to shoot photographs that penetrate the object's outer layers, getting rid of any reflection and glare.
Cross-polarization is a simple technique, but requires a powerful light source whose polarization can be oriented at will, in order to obtain the right degree of glare filtering.
In this example you can compare different cross-polarization stages, obtained by rotating our 3D printable polarizing filter that we applied on a Relio² 4000K with 25º aperture lens.
As the polarization approaches 90º, the glossy reflections decrease and then disappear completely.
If you pay attention, you'll notice that the shadows remain unchanged, as a proof that we're only filtering the reflected light, without any sort of diffusion.
This result is within everyone's reach: you need one Relio², a rotatable polarizer that can be downloaded from our website and printed in 3D, and a thin linear polarization film.
The shooting device is a generic smartphone, with a layer of polarizing film temporarily applied in front of its camera.

Example #1: Photographs of curved and glossy surfaces

A scenario where cross-polarized photography definitively solves all the problems of surface glare, is the shooting of curved surfaces, such as fruits, vases, packagings, artefacts and works of art.
Equipment used: one Relio² 4000K, a smartphone and our rotatable polarizer with a linear polarization film inside. That’s all you need. Not bad, right?

Here are the 3D-printable accessories used in these shots

We will never stop telling you this: Relio² is the most versatile professional illuminator ever made. You can make it even better by 3D-printing our already-engineered accessories. Thanks to this, you can polarize its light, tighten the beam, change its shape, direction, intensity and sharpness. Enjoy!

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Frequently Asked Questions

How do I get a Relio² kit?

Currently, Relio² is sold exclusively on this website.

Does it have an internal battery?

No. We want Relio² to withstand years and years of 24/7 use. An internal battery in such a small and powerful device would be able to power Relio² for just 15 minutes at full brightness, with a lifetime spanning no more than 6 months. Name - if you can - one product with an integrated, non-removable battery that’s still 100% funcional after years of use...

How do I power it up?

Via the external microUSB connector. Every USB outlet in the world capable of providing at least 1A of current is suitable.

Why does Relio² still have a microUSB plug instead of the newer USB-C?

The answer is simple: maximum cable length and cord flexibiity. USB-C is born to transport a lot of data channels, so the internal wire count is 4x more, making it very thick and more rigid. For the same reason, USB-C cables lenght is limited to 2m. In the Relio² Base Kit package, we include 1x 1.5m magnetic, nylon-braided microUSB cable and 1x premium, gold-plated, nylon-braided 3m microUSB cable from a premium brand.

Can I use USB-C to USB-A, or USB-C to microUSB adapters?

Yes, of course.

Is the magnetic cable user-replaceable?

Yes. Contact us for a suitable replacement.

What if I use Relio² a lot and some parts wear out?

We engineered all the Relio² parts subject to normal-use wear and tear to be of common availability. Contact us for suitable replacements.

Does it have a manufacturer warranty? What does it cover?

We offer 2 years of manufacturer warranty on our terms of use and warranty. Please consult our sales terms for details.

How much power does Relio² draw?

1A at 5V DC. Since it integrates a step-down buck converter capable of up to 15V DC, power consumption at higher voltages will be less.

Can I power it up with a car battery or other sources of electricity?

Yes. Every source ranging from 4 to 15V DC is suitable. Input lines are protected from overvoltage and reverse bias. For more info, please consult the manual or our technical specifications.

Is it water resistant?

Yes, moderately up to IP53. For more info, please consult the manual or our technical specifications.

How many units can be operated through the smartphone App?

On iOS, we successfully tested up to 16 devices. On Android, it varies depending on the platform (around 5 units). Please note that aggregate brightness control function is still in development.

Can I develop a custom Bluetooth BLE application?

Yes. You can refer to our BLE API documentation. Please note that developing commercial applications is not permitted unless an explicit consent is received by us. Please contact us for more info.

I need assistance and documentation on how to operate Relio² via an external, wired microcontroller like the Arduino®.

We will provide you with full documentation on how to operate Relio² through logic-level signals. Please contact us for more info.

I need assistance in determining how many Relio² kits I need for my work.

We can do digital simulations tailored to your environment. Drop us a message via the contact form.

Do you ship worldwide?

Yes, with some limitations in some remote areas. If you don't see your Country listed in the shipping form, please contact us.

You said that the LED will be upgradeable. How will you handle that?

This is a commitment and we will honour it in case the technology advances. All the future LED upgrades will be backwards-compatible, so you'll be able to ship your Relio² kits back to us for the upgrade, for a minimal servicing fee.

Can I disassemble the LED and eletronics by myself?

Yes, and it's rather easy to do, but the warranty will be voided.

I accidentally damaged something in my unit. Are spare parts available for sale?

Yes, depending on stock availability. Please contact us and we will help you.

Do you sell physical versions of your 3D-printable accessories?

Currently no, but we partnered with some local and international suppliers that will be able to 3D-print and ship them to you. Please contact us for more info.

I want to sell your 3D-printable accessories.

Yes, why not? We release all our accessories under the Creative Commons CC-BY-4.0 license, so you are free to do that. Please remember that you have to mention us on your sales page. Also, please note that we may also link to 3rd-party items, and they may not share the same license terms of our own accessories. Always check the license bundled with each accessory that you download.

I want to be a reseller of your product.

Sure. Drop us a message via the contact form.

I want to be the exclusive distributor of your product.

Maybe. Drop us a message via the contact form.

Let’s know each-other!

We’re a super-small company that listens to its users.
You can help us make a difference.

Send us a message to unlock all our free accessories.

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Let’s know each-other!

We’re a super-small company that listens to its users.
You can help us make a difference.

Send us a message to unlock all our technical documentation.

The download links will appear immediately.

Let’s know each-other!

We’re a super-small company that listens to its users.
You can help us make a difference.

Send us a message to unlock all our technical documentation.

The download links will appear immediately.

Relio² 2020+ Editions. Now Available!

We engineered some majestic Editions of Relio².

After our successful Kickstarter® campaign, they are ready to be delivered. Click here below to discover more!

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