Important first step. Do not take any more photos on the stick - they may over-write the files. The files are still there and there is free software to retrieve them which is said to be quite effective. Type 'retrieve deleted files' into Google and you will find some software options you can try. There are also some programs you have to pay for. If you are worried about making things worse, take some photos on another stick, delete them and try out some of the software to see which you think works best.
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Important first step. Do not take any more photos on the stick - they may over-write the files. The files are still there and there is free software to retrieve them which is said to be quite effective. Type 'retrieve deleted files' into Google and you will find some software options you can try. There are also some programs you have to pay for. If you are worried about making things worse, take some photos on another stick, delete them and try out some of the software to see which you think works best.