Individually these imperfections do not amount too much, but when they occur at the same time imagery becomes unusable.
Alignment & Accuracy
Alignment and accuracy go hand in hand. Depending on the project you may need something that prioritizing being visually appealing, but less accurate.
The cause of these varies between aircraft, cameras, flying conditions, and the processing methods used.
Often this occurs around the image seamlines over features above ground level which is more common among airplane imagery than drone imagery.
When you take images of dynamic scenes such as a road with moving cars or tall buildings, ghosting can occur.
These features will have duplicates and look semi-transparent.
When taking imagery of tall objects, buildings, trees, telephone poles, etc. if there is not adequate coverage you will get artifact lines around the features.