I tried the Tokina 17mm F4 on my Sony A700 and was pleasantly surprised that it performed very nicely! It has been lying for many years unused in the cabinet since I stopped using film. Perhaps due to the sweet spot of the A700 1.5X crop factor A700, the images that came out of the camera were sharp for a wide angle lens. The colours and saturation were beautiful and I do wonder if it were to be used on a full frame camera(A900?), will it unleash its full frame wide angle glory!