I’ve had a few people ask how I line up my panoramas, so I thought it was about time I shared my processing technique.
Currently I am using PTGui, its a pretty cool program and works really well. The only proviso is that you have a panoramic head that is correctly aligned for your camera and lens. Without this its likly that the software will have a hard time getting straight lines properly aligned. It took me quite a bit of time to get this nailed, but the pain was worth it.
Firstly I batch process my images in Photomatix for HDR. This is obviously optional.
Select the images in Bridge or Explorer. Here you can see that I have a full set of ‘up down and straight’ shots.
Fire up PTGui and you are presented with the screen below
Drag your images into the window and they will appear in the top portion of the window. PTGui does a good job of setting them up in the same orientation.
There are a couple of things to note here:
- Enter the correct focal length of the lens and crop factor. I use a 8-16mm Sigma and find the 7.98 works better than a straight 8mm. The crop factor is also slightly different from the exact x1.6.
- Make sure that you have the correct type of lens selected – either fisheye or rectiliniar.
- Click on the ‘Advanced’ button on the right to reveal more tweaking tabs.
Click on the ‘Align Images’ button and the application will do its thing, another window will pop up displaying the image stitched together. The initial result may or may not be good, this comes down to having a fair amount of overlap in the shots themselves and a well aligned head.
The next step is to use the control points table to get rid of any way out alignment. Click on the green grid icon fourth from the right in the main window.
Delete any control points that are above 50 in the distance range check the full image paying particular attention to the verticals and horizontals. To do this simply click the top control point and scroll down . Holding the shift key select the range, click and press delete on the keyboard.
This can be further tuned by deleting points that are further apart. To get a ‘very good’ all control points have to be below 10 I believe.
To view or add the control points themselves use the ‘Control points tab on the main application window.
- Images that are linked are shown in bold on the tabs.
- If no points are visible on a particular image these can be added manually to adjacent images.
- If verticals are not vertical, select the same image in both panes, place the cross-hairs on the vertical point in one pane, then the other. When the flashing number appears right click and select vertical. This will appear at the foot of the window in the table under the ‘Type’ column.
- The same can be done for horizontal lines.
Another neat feature in the latest versions of the software is the mask tab. This enables the user to mask in or out parts of an image. This is especially useful if the image has a lot of movement, particularly cars or people.
Simply paint green to keep, red to remove. Be careful though, this can only be done on the overlaps.
Select the Optimize tab and simply click on the ‘Run Optimizer’ button.
Minimize Lens Distortion can make a difference, however I generally leave this at ‘Medium’
The next step is optional. Select the Exposure / HDR tab and click ‘Optimize Now’ this will tweak the vignette that may occur on very wide angle lenses.
The final step in the process is to create the panorama itself.
- Select the file size and output format.
- Decide where the image is to be saved.
- Click ‘Create Panorama’.
Depending upon how much bending of the image is required will make a huge difference to how long this takes. Sometimes its a good idea to get a cuppa or do the washing up, others its over very quickly indeed.
Here’s the image itself just before being stitched.
You can see the full zoomable 360 in THIS POST