Good advice and good writing. But the title is misleading: this is photography for aspiring photographers, not esp. geeks. I was expecting more geeky things.
For example, I have recently been toying with making a kind of photobooth / selfies machine for parties by connecting a DSLR with a Raspberry Pi; people take pictures of themselves with a remote (the excellent Yongnuo RF-603 which is radio, not infrared); the Pi downloads the images (with gphoto2), resizes them, prints the date, and uploads to a server.
People can see their images on their phones less than a minute after it was taken. It's a lot of fun.
Around 2012 I was asked to make a photo booth for a friend's wedding. I ended up managing to rig an old-fashioned doorbell to an Arduino to give me a 3-second countdown, attached to a DSLR for the photo, an eye-fi card for the wireless connectivity because I think the camera didn't have on-board WiFi, and an iPad attached outside the both that always showed the last photo and let you scroll back.
I think I'd have to recreate it from scratch if I had to do it again because I have no idea now.
Yeah, Eye-Fi (the company) doesn't exist anymore, probably because newer cameras all have wifi. But for a photobooth at a party that needs to run unattended, it's better to use an old camera you don't care about too much ;-)
Having gphoto monitor the camera constantly (my first attempt) is not a good solution, because if for whatever reason the connection to the camera is lost, gphoto just dies.
In my current setup, gphoto downloads new files at regular intervals (via cron), puts them in a directory on the pi, which is then rsynced to a server. This is very resilient: it survives rebooting the pi, turning the camera off or on, etc., with zero intervention. All it needs is a network connection to the Pi (wifi or ethernet) and nothing else. No app, no phone nearby, no bluetooth, no nothing ;-)
I use an old Pi 3 for this that's plenty fast; it would probably work on a zero (but I've never been able to buy one) or other single boards. Ideally it could be put in a small box that could be mounted on the flash shoe and that would also act as a remote...
For example, I have recently been toying with making a kind of photobooth / selfies machine for parties by connecting a DSLR with a Raspberry Pi; people take pictures of themselves with a remote (the excellent Yongnuo RF-603 which is radio, not infrared); the Pi downloads the images (with gphoto2), resizes them, prints the date, and uploads to a server.
People can see their images on their phones less than a minute after it was taken. It's a lot of fun.