1. Download free Picture Information Extractor here.
https://www.picmeta.com/download.htm
2. Install PIE (Picture Information Extractor) on your PC (32/64bit Windows )
3. Take a photo from your Sony cameras. It could be JPG or .ARW.
4. Open the software and go to your photo and look for the parameter on your right panel called “IMAGE COUNT” under “SONY”