The « Optical Group » is dedicated to spectroscopy studies with diffraction gratings secondary lenses mountable on cameras.

Set up of an optic bench

February 13th, 2012

Bringing into operation our spectroscopic test bench allows calibrating and studying the optical quality of various imaging devices available on the market, as well as a comparing the different existing diffraction gratings. The goal is to determine the optimal characteristics of operating conditions.

Along with our analysis soft wares, this system allows a very precise identification of spectral lines.

Compact fluorescent bulb spectrum

Neon lamp Spectrum

Characteristics comparison of 3 different diffraction grating types

Spectral lines identification sharpness.

V.I.G.I.E Project

September 14th, 2011

During the last days, many tests done with the software Théodolite, for IPhone and IPad, associated to some works of our own on GoogleMap application, have shown that a large number of technical solutions can be found to allow large scale management of spectrum data potentially acquired from UFO observations.

Toward a centralized and automated processing of photographic data

In order to set up a structure able to centralize technical and spectral data, we here announce the launch of the project : V.I.G.I.E : “Visual Integrated Geolocalisation for Identification Experiment“.
See the dedicated page.

Diffraction gratings Geolocation

September 12th, 2011

carte_bonnettesSince 2007, many diffraction gratings have been distributed worlwide, in more than 25 countries. Two models of diffraction gratings are circulating: one as a slide frame, the other one as an adhesive cap for mobile phone. To better visualize the distribution of them, each grating has been geolocalized from the zip code used for sending. View the map.

Bonnettes à réseau adhésives disponibles

November 4th, 2010

The adhesive diffraction grating for Cellular, are now on sale at a price of 10 € plus shipping of 3.25 €.

Visit the dedicated page for more information.

To satisfy the greatest number of requests, one item per order will be recorded.

First approach to spectroscopy usage for UFO phenomenon study

October 25th, 2009 (update December 13th ,2010)

A summary paper of essential knowledge on diffraction gratings.


Dec 13th, 2010
Using spectroscopy for the study of Unidentified Flying Objects


How to build a diffraction grating kit for a mobile phone imaging device

October 18th, 2009

This document outlines a step by step method to build a small device allowing adapting a diffraction grating on your mobile phone lens.


Oct 18th, 2009
How to make a diffraction grating kit for a mobile phone imaging device


First real-life conditions spectrum shots

March 24th, 2009

A paper about real condition night shots of a bright object aloft using an optical diffraction grating, and the analysis of the captured spectrum. Read more.



Quick guide to diffraction gratings

September 30th, 2007

Quick guide (3 PDF pages) to optical diffraction gratings and spectroscopic caps for cameras and imaging devices : where to get them, how to mount and use them (soon in english).


Sept 30th, 2007
Information sur les réseaux de diffraction


Optical diffraction grating

June 19th, 2007

Here is the first explanatory work about diffraction gratings caps for photo cameras :


June 19th, 2007
Using spectroscopy for the study of Unidentified Flying Objects (UFOs)


Some spectral emissions

September 30th, 2007

Some videos explaining experiences allowing revealing spectral emissions from various typical light sources :


CRAS 1975
30 sept 2007
Sodium spectrum of a flame
CRAS 1975
30 sept 2007
HF plasmoïd high resolution spectrum
CRAS 1975
30 sept 2007
HF plasmoïd high resolution spectrum


How to make a high precision spectroscope device

September 30th, 2007

Video showing the construction of a spectroscope :


CRAS 1975
30 sept 2007
Construction and use of a high precision spectroscope