Device for observing an object, present in a sample, comprising: - a holder, able to receive the sample; - a light source, able to emit a light beam, called the incident light beam, in order to illuminate the object; - an image sensor, configured to acquire an image representative of radiation back-scattered by the object under the effect of an illumination by the incident light beam; - a screen, lying facing the holder, so as to be exposed to radiation back-scattered by the object when the latter is illuminated by the incident light beam, so as to form, on the screen, an image (I 20), called a scattergram, representative of said back-scattered radiation; - the screen comprising a first face (20 1) exposed to the back-scattered radiation; - the screen lying between the light source and the object, and comprising an aperture, through which the incident light beam propagates before reaching the object, the screen comprising a second face (20 2), so that the scattergram formed on the first face (20 1) appears on the second face; - the image sensor being configured to acquire an image (I 30) of the scattergram (I 20) formed on the screen, the screen being placed between the image sensor and the object, the image sensor being coupled to the second face of the screen by a focusing optic; the device being characterized in that it comprises a reflective element, able to direct the light beam emitted by the light source toward the object, through the aperture, the reflective element being placed between the object and the image sensor, and in that: - the reflective element absorbs at least 30% of the back-scattered radiation emitted by the object; - and/or the reflective element is fastened to a holder, the holder absorbing at least 30% of the back-scattered radiation emitted by the object. - a holder, able to receive the sample; - a light source, able to emit a light beam, called the incident light beam, in order to illuminate the object; - an image sensor, configured to acquire an image representative of radiation back-scattered by the object under the effect of an illumination by the incident light beam; - a screen, lying facing the holder, so as to be exposed to radiation back-scattered by the object when the latter is illuminated by the incident light beam, so as to form, on the screen, an image (I 20), called a scattergram, representative of said back-scattered radiation; - the screen comprising a first face (20 1) exposed to the back-scattered radiation; - the screen lying between the light source and the object, and comprising an aperture, through which the incident light beam propagates before reaching the object, the screen comprising a second face (20 2), so that the scattergram formed on the first face (20 1) appears on the second face; - the image sensor being configured to acquire an image (I 30) of the scattergram (I 20) formed on the screen, the screen being placed between the image sensor and the object, the image sensor being coupled to the second face of the screen by a focusing optic; - the reflective element absorbs at least 30% of the back-scattered radiation emitted by the object; - and/or the reflective element is fastened to a holder, the holder absorbing at least 30% of the back-scattered radiation emitted by the object.