All filters affect significantly the focus accuracy and for shooting at maximum aperture, close to the minimum focusing distance almost unsuitable ...
The UV filter and the ND filters do good service, but again, you see the "cheap" multi-layer coating in image quality ...
The Circ. Polarizer is my biggest disappointment as this, depending on the position, proper streaking runs through the image (especially in direct sunlight).
For herrantasten okay, as lens protection perhaps even suitable in the case of UV filters, but useless for better than halfway decent pictures ...
