Specialist Equipment
Creating large panoramic images requires some specialist equipment and a fair amount of time and patience both in the field and later when processing the images. However, the results can be very rewarding !
|
|
Firstly, it is essential to use a panoramic tripod head to rotate the camera and lens through what is called the 'nodal' point. This is the point about which a lens is rotated where close and distant subjects focused on the film plane maintain their relative positions to one another. If this is not done, foreground and background subjects change their relative positions when the camera pans, causing misalignments between shots.
I use a Manfrotto MN303 head which provides a way of determining the nodal point of variety of large SLR cameras and lenses. It also has a series of click-stop adjustments so that the camera can be rotated to provide images that consistently overlap. As you can see it is a sturdy beast !
Secondly, some image stitching software is required to combine these images together prior to normal Photoshop processing. This software uses complex algorithms to warp the images into a cylindrical projection and blend them together where they overlap.
|
|
Making Panoramas
To make a panorama, I follow the procedure below :
- I mount the camera on the panoramic tripod head in portrait mode to capture the maximum image height. The head is levelled to ensure that the horizon is kept constant. I may also use a remote switch which allows very long exposures to be taken - useful for low level light conditions such as night scenes or for the inside of buildings.
The click-stops are adjusted so that the images will overlap by approximately 30%.
- The camera is put into manual mode so that all automatic exposure settings are turned off. When rotating the camera the exposure for each image will no longer be re-adjusted to the different lighting conditions between the start and end frames - especially if shooting towards the sun.
- A series of images are taken and the camera is rotated clockwise between frames.
- The images are then processed on my PC to stitch them together. I create the resulting panorama as a Photoshop .PSD file, where each composite image is rendered onto its own layer. These layers combine together to give the complete panorama.
- Using Photoshop, adjustments are made to the individual layers to remove any ghosting or other artefacts that may result from the stitching process and to fine-tune the exposure and blending. This step is the most time consuming since vary rarely do images blend seamlessly together without the need for adjustment. Finally, the layers are all flattened to form the completed panorama which is then cropped to its final size.
- The panorama can now be processed in Photoshop just like any other image to adjust levels, colour, sharpness etc. Please see the Processing Images page for more information.
Typically a large panorama can be printed several feet long at 300 dpi and without up-sampling - the detail is incredible! It takes a very long time to generate images of this size, since they are made up of several 12.8MP frames. Some of my favourite panoramas can be seen in my Showcase Gallery.
By joining even more images together, a complete 360° view can be taken. A selection of these can be seen as mini movies in the 360° Virtual Tours gallery, or indeed as printable images throughout my web galleries.
|
