Sometime our photos are chance encounters, when we happen to have our camera or possibly “prepared” chance encounters, when we go out looking for photos and chance brings us all the right elements.
Another type of photo is an assigned photo. The assigner may be you or someone else.
You can (and may well) assign yourself photos all the time. Maybe you are shooting an event or doing a special photo for someone.
“Someone else” could be a client, friend or relative. It’s a gig. You are assigned to create an image. There’s a bit more pressure.
The right kind of pressure ain’t so bad though. When you know you need to deliver, you are more attentive, more focused on getting the shot or creating a decent collection of images. You are also quite aware that other people are going to expect to see your work, so there may even be more incentive to do your best work and maybe push your own limits a bit. Pushing your limits expands them.