I was wondering if there was an 8 pin arduino chip available
It depends on your needs. Examples: It is very unlikely any given Arduino library will work on a ATtiny processor. If you need a basic core (digitalRead, digitalWrite, etcetera) then you're in luck.
I already have an arduino board to program it with, but what is the smallest chip available?
I like the ATtiny85 processor. It has enough SRAM and Flash to build fairly complex applications but is physically small (8 pin chip).
I only need one digital output (making a camera take a picture every 10 seconds)
An ATtiny13 would certainly be capable of doing something like that. You may have to directly manipulate registers to keep the code and data size small enough to fit.
Would you be able to burn the arduino bootloader onto an attiny13?