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. <EOS>