If the bright sky is hampering the quality of your images, then use the 150 x 170mm Medium-Edge Graduated Neutral Density 0.3 Filter from LEE Filters that reduces exposure in selective areas. This neutral density filter has dense edges and clear middle that allows you to darken extremely bright areas of the image without affecting the remaining portion. This filter has a medium-edged line of transition that gives a sharp transition between areas of a picture making it useful for images such that rooftops and mountains that are are bulging in the sky. It has up to 2x Filter Factor and provides a 1-stop reduction of light entering the lens.