I just starting to create my first panoramas, and I have trouble taking a shot of the sky. The Sigma fisheye lens won't focus, and cannot take the picture of the sky. Do I have to focus the lens manually or? Also, when the sun is shining very strong in the middle of the sky, the picture comes out with problems. Do you have any suggestions from your experience??
Most professional panorama shooters do not use "Auto-Focus". The Sigma 8mm is pretty much in focus on everything when set to "Infinity". So the answer to your question is F/8.0 Manual Focus setting set at Infinity. If you are not shooting RAW (and you should be) make sure you are in Manual Shooting mode and set the White Balance to suit the scene.