I have an 11x56 Oberwerk binocular, which is pretty good in low light condition.However, it is quite big and cannot carry it often while going out for a tour.Therefore, identified this monocular for small size. I went through many reviews on 'amazon.com'and elsewhere and found most people have commented positively on it.So, I ordered it. However, while using it, my opinion changed quite a lot on this.I find the contrast of objects seen through it is quite low compared to a CelestronNature porro prism binocular. Given the exit pupil of 5 mm for this monocular, one expectsquite a bright view through it in the evening time. However, the view is significantly dimmerthan a typical porro prism binocular with an exit pupil of 5 mm.The reason for it seems to be due to use of Roof prism. Given its price, Celestronmost likely is not using Phase coating for the Roof prism, which is causing loss of light andconsequent lack of contrast.However, given its price, size and the details one can see using it in daytime as compared to naked eyes, I consider buying it is not a loss.