Yeah, that definitely works better than taking a photo, but it adds a huge amount of time to your reading time. I just leave the camera on my phone on, and press the volume button whenever I want to take a picture, and continue reading. It may not be absorbed as much, but you have a clear reference, very quickly, and you can save as much of the book as you want.If you read something that you want to remember, I recommend writing it down. There's something about writing that stimulates the brain. Even if you don't look at your notes, you'll be able to recall the item later.
To really commit the idea to memory, play with it once you've written it down. If it's a theory, try to debunk it. If it's a concept, describe how it applies to your process.
It works for me. Maybe it'll work for you.