We're Here to Help

Everything you need to help you with your Diffuser & Cosine Corrector accessory.

Measurement Accuracy

This cannot be expressed with a simple number or percentage because there are various factors in which the diffuser accessory is superior:
  1. A paper consists of a non-homogeneous structure which is why it allows different amounts of light to pass through depending on how precisely it is placed over the camera. The material in the diffuser accessory, on the other hand, transmits light very evenly.
  2. The paper lies flat on the camera. As a result, light from different directions is not optimally deflected and measured correctly. This is particularly important when measuring in a confined space (e.g. grow tent) with reflective walls. The diffuser accessory is cosine corrected and does not have this problem.
  3. Each paper is different in terms of light transmission depending on weight, manufacturer and lot number. The app uses an average value to calculate the light intensity, but this may differ from the paper you are using. However, the diffuser accessory has a known transmission and is manufactured by us in a special process in such a way that the differences between two different accessories are negligible.
How much the measurement with the diffuser accessory differs from the measurement with the paper diffuser depends on the light source to be measured, your environment, and your paper.
The most common cause of this is, that the app’s settings have not been adjusted. Make sure you’ve configured the app to adapt for a paper diffuser or the diffuser accessory, depending on what you’re currently using (see here). Unfortunately, it’s impossible to detect this automatically.

The second common issue is that you are not using the exact paper weight as advised in the app which is 80 g/m² or 22 lbs.

And lastly, even if you got the settings right and chose the right paper you can still see differences in your measurements. This is because paper isn’t a perfect diffuser for many reasons. Firstly, it can not be manufactured as precisely as required and will still vary in translucency depending on the manufacturer and production batch. Secondly, paper has a grainy structure, meaning its light transmission will vary depending on how you place it over the camera. Thirdly, the paper diffuser cannot properly correct for light hitting from different directions.

These uncertainties when using a paper diffuser are exactly why we’ve invested a lot of effort in engineering the diffuser accessory that fixes all the measurement errors described above (and more). You can trust measurements taken with the diffuser accessory.


Hold your device under bright light and look through the darkened glass to find the front camera lens.
If unclear, run the app and slowly slide a pen over the top of your device. The background will become dark as soon as the pen is over the front camera. Lightray Diffuser & Cosine Corrector
Yes, unless the case doesn't allow the accessory to fit tightly — there should be no gap between display and accessory. If so, we recommend removing the case for proper fitting.


Please check our full device compatibility overview here.
Your order will leave the warehouse within one business day after a successful payment.
Shipping is handled with the fastest method available to us using DHL Warenpost International Premium, which also includes parcel tracking. Typically, your local postal service (e.g. USPS, Correos, …) will handle the final delivery.

Your order will be shipped from Germany by our logistics partner Omnitrade e-commerce GmbH.
Expected delivery times vary by region:

  • North America: 6–10 days
  • Europe: 1–5 days
  • Asia: 6–12 days
  • Africa: 6–18 days
  • Oceania: 12–18 days
  • South America: 16–20 days
The white surface of the diffuser may show slight irregularities due to the specialized material and production process. This does not negatively affect the measurement quality and is not a cause for concern. Each manufactured part is checked by our quality control before it is installed.

Help Needed?

In case you need any more support, our team is here to help.

Contact Us