A:AnswerI don't think it will work without an adapter. Your A55 looks like it has the older Minolta style flash mount which is different than everything else. This flash is set up to work with a standard hotshoe even though it does include the Sony Multi Interface contacts.
A:AnswerThis comes with a transmitter that mounts on the Hot Shoe of your camera. as long as the camera has a hot shoe adapter on it, it will be compatible.
A:AnswerIt should work at least in manual mode. It is hard to tell from pictures on the A3000 if it has the other needed contacts to operate in TTL mode. It does look like you have standard hotshoe mounting so at least it will mount up successfully.
