The Necessity and Pitfall of Augmentation in Deep Learning: Observations During a Case Study in Triplet Learning for Coin Images Topics: Advanced Learning Methods; Classification and Clustering; Deep Learning and Neural Networks; Feature Selection and Extraction; Image and Video Analysis and Understanding; Industry Related Applications; Machine Learning Methods In Proceedings of the 9th International Conference on Pattern Recognition Applications and Methods ICPRAM - Volume 1, 387-394, 2020 , Valletta, Malta