What are calibration groups good for?
A calibration group is a set of calibration frames taken under the same conditions.
In general, images with the same body/optics are registered easier. To give you a use-case example, using calibration groups can be useful for cameras with fixed optics (like GoPro), objects with a weak texture or when you want to constrain a set of cameras to have the same focal length. Grouping camera parameters is useful for tangential distortion caused by physical elements in lens not being perfectly aligned.
How do I create a calibration group?
These groups can be generated automatically and so all files with matching characteristics grouped together. Alternatively, a user can create groups manually.
RC is able to group camera parameters automatically, when images are added, using EXIF data. To enable/disable this option, either go to the WORKFLOW tab / Settings / Import Settings and set "Group calibration by Exif" to True/False, or click Group/Ungroup in the Inputs panel which shows up when clicking once on the Images root in the 1Ds panel. When you disable calibration, each camera calibration will be optimized independently.
You can also set constant calibration to all of the images included in your project at once (manually) by clicking Constant in the Images panel / Inputs. This often helps when some images have been misaligned. However, user-defined changes in these parameters usually lead to not very realistic changes in model alignations.
A calibration group is a set of calibration frames taken under the same conditions.
In general, images with the same body/optics are registered easier. To give you a use-case example, using calibration groups can be useful for cameras with fixed optics (like GoPro), objects with a weak texture or when you want to constrain a set of cameras to have the same focal length. Grouping camera parameters is useful for tangential distortion caused by physical elements in lens not being perfectly aligned.
How do I create a calibration group?
These groups can be generated automatically and so all files with matching characteristics grouped together. Alternatively, a user can create groups manually.
RC is able to group camera parameters automatically, when images are added, using EXIF data. To enable/disable this option, either go to the WORKFLOW tab / Settings / Import Settings and set "Group calibration by Exif" to True/False, or click Group/Ungroup in the Inputs panel which shows up when clicking once on the Images root in the 1Ds panel. When you disable calibration, each camera calibration will be optimized independently.
You can also set constant calibration to all of the images included in your project at once (manually) by clicking Constant in the Images panel / Inputs. This often helps when some images have been misaligned. However, user-defined changes in these parameters usually lead to not very realistic changes in model alignations.

There is also a possibility to group images individually: select one or more images in the 1Ds panel and re-set the parameters in the panel which appears after selecting images. In Calibration group and Lens group use "-1" if you do not want to group the parameters. Any other number in these fields means to group the parameters. Further, to group camera parameters, set the same number to both of them.

NOTE: Calibration is processed with alignment.
For more information have a look at the Camera Settings in the Help section built in your RC.
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