Panoramic the how’s and the why’s.

After gathering information from many web sites I have distilled the useful information for shooting panoramas.

Use a digital camera, ideally one which allows you to manually set the exposure and focus. Most automatic camera will want to readjust the exposure as you sweep round in a 360º path, due to the changing light conditioned. As it encounters areas that are well lit or areas that are in shadow it will try to average out the amount of light in the image. As we are using a digital camera you need to set the white balance to a non-auto setting, fixed daylight outside, fixed artificial inside. If you where using a film camera you would use the same type of film through out, daylight or tungsten. A set exposure will help you when it comes to joining adjacent images together as they will tonally similar, left side of one and the right side of the other.

Simulated auto exposure

Fixed exposure

The same is true for autofocus setting. As objects in front of the camera become closer or move further away the camera will try to refocus. This will give you areas of different focus thus making it harder to join areas together.

Combined image

 As you can see in this combined image the focus has changed between shot making it difficult to join the images in the middle.

The next requirement is a stable platform to shoot the images on. A tripod with a built in sprit level so the camera can be level with the horizon and true to the perpendicular. This allows the centre of the lens to travel through the same plane, minimising parallax distortion between frames.

When shooting set the camera in the portrait position (Tall rather than wide) You will have to shoot more frames but you will end up with a better quality pan which has a higher resolution and you may also find it easier to work on. There are charts which list the angle of view of a lens and you could work it out mathematically how many frames you need to shoot. When you are our on location shooting, the chart will be the last thing on your mind. You should work on the principle of 35% to 50% over lap of adjacent images. Look at each frame, visually noting where an object is in the viewfinder and where a 40% movement would put an object so it is at the edge of the next frame. After you shot that frame rotate the camera to the next position and repeat until you return to the position you first started. You will have covered the 360º. I always make the first and last frame the same image. Then you know you have shot everything. This could be at least 20 images per panoramic.  

Visually tracking parts of the image across the frame

A big thank you to the webs sites below for there help.

Pan guide 1 Pan guide 2 Pan guide 3 Pan guide 4