Specifications?K-50 | RICOH IMAGING says: • Operation-confirmed SD/SDHC/SDXC memory cards: [Panasonic/Toshiba/SanDisk] SD card memory capacity: 1GB, 2GB; SDHC card memory capacity: 4GB, 8GB, 16GB, 32GB; SDCX card memory capacity: 64GB. [SanDisk] SDXC card memory capacity: 128GB. [Eye-Fi Japan] SDHC card memory capacity: 4GB (Connect X2), 8GB (Mobile X2/Pro X2),16GB (Pro X2) . Also: Compatible with UHS-I speed class. • U se of a h igh-speed SD memory card is recommended for movie recording, as therecording may terminate during recording if the writing speed is too low. • Operation tests have been conducted by the individual memory card manufacturers.
So, it was tested with 64GB, officially.