"Hacking" the remote control

 

Below is how the remote control for this camera (Nikon D700/D800) works. I have no idea how common this design is, so you'll have to open yours to see how it works. There are three metal plates which can be bended by pressing the button.

Situation I: The control is at rest and none of the metal plates make contact with each other.

Situation II: The button is pressed down halfway and the first two contacts touch each other; the camera measures the exposure and focuses.

Situation III: The button is pressed down completely and all three plates make contact with each other; the camera takes the picture.

Situation IV: This is what my "hacked" remote control looks like. I soldered wires to all three plates and the connections will be activated electronically by using a relay (see below).

 

The sensors

 

This system is based on two active IR detectors. The sensors have a high output when they detect the light from the IR-source, and low output when the beam is blocked. The signals from both detectors are connected to a NOR-gate, which in turn will give a high output when both detectors are blocked simultaneously. This high signal from the NOR-gate then activates the relay which will make the camera take a picture. There are also two separate control LEDs for each sensor attached in my system, but they are not included in this scheme.

 

The breadboard with the main electronics.

 

The separate parts and the little box in which they are stored.

 

The lock with two switches, one main switch to the right and one switch to the left to activate the control LEDs. When the control LEDs are switched on, if nothing blocks the sensors both LEDs are on (left), and when both beams are blocked the LEDs are off (right).

 

The set-up

 

All parts are mounted on a metal plate, with the sensors mounted on an aluminum frame. Both the camera and the sensors are mounted on sliders to achieve as much flexibility as possible with regard to magnification.

The camera is mounted on a modified Velbon Super Mag Slider. I made this modification to allow for very small steps when doing focus stacks with microscope lenses (10x enlargement). It is not needed for this purpose though, it's just there because, once attached, it is hard to remove and I am a lazy guy.

 

Front view. The sensors are the black rectangular pieces on the aluminum frame, with the upper ones being the IR-LEDs and the lower ones the detectors ⇛ normal || IR beams drawn.

 

Side view. There is another hole in the frame located under the front end of the Velbon Super Mag Slider, in case I want to move the camera closer to the target. It is also possible to slide the sensors (and thus the target) closer to the camera using the rail on the left. The flash is mounted on a Tether Tools articulating arm, and it is equipped with a diffusor for better lighting.