If you simply put photos in the Trash, you can recover deleted photos by opening the Trash (left-click on the Trash icon) and drag the photos from the Trash to your Desktop or other desired location.
2. Recover deleted photos with Mac photo recovery freeware
If you emptied the deleted photos from Trash, you need a professional data recovery program.
Mac photo recovery software: M3 Mac Data Recovery Free is a professional and free Mac data recovery software which can recover deleted photos, pictures, songs, movies, and other multimedia files Mac-based hard drive as well as external hard drive, iPod, USB drive, SD card, digital camera, CF card XD Card, MMC card, memory stick, memory card, MP3/MP4 player, etc. in macOS 10.12 and Mac OSX 10.11/10.10/10.9/10.8/10.7/10.6.
Tutorial to recover deleted photos with Mac photo recovery freeware in Mac OSX
Step 1: Download, install and launch Mac photo recovery freeware: M3 Mac Data Recovery on your Mac OSX computer.
Step 2: Select the location where you want to recover deleted photos and start scan.
Step 3: M3 Mac Data Recovery is scanning the deleted photos
Step 4: Select the found photos you expect to recover and then click Recover to save them.
Besides recovering deleted photos, M3 Mac Data Recovery Free can also recover photos from formatted, deleted or lost drive, etc.