The scope is very tiny. When I got it, I can see the scope is well made. According to other user report, it should be a very fast scope (F~3.8-4). It is very challenging to make a good fast refracting scope. When it is at 9x-15x, the image is fine and clear. When it is higher than 15x, there is obvious chromatic aberration.Compared with the Nikon ED50 with 13-40x zoom, hummingbird can barely compare with ED50 at 9-15x. However, above 15x image can not match Nikon due to hummingbird severe CA.