Hi, so I'm currently sitting on my floor say hi to my plants Anyways, maybe you've gotten yourself a reusable plastic film camera and you're wondering to yourself when should you use the flash? So I would suggest every time when you're indoors and low-light situations Always always use the flash when you're outdoors in sunny situations You don't really need to use the flash However, I would suggest using the flash when your subject isn't shadow or if your subject is backlit Unless of course you want to get silhouettes then you don't need to use the flash However, most of the time if the light source is behind your subject then you should use the flash Also when you're outside and you're in low-light situations like say it's cloudy or it's sunset Then by all means use the flash It also really depends on your own artistic intent So I would suggest playing with your settings use the flash don't use the flash and Get a feel of when it works for you or not. Anyways, just have fun. Cheers