Sunday, 19 September 2010

Sigma DP1s external trigger

The Sigma DP1 & DP1s are great cameras for aerial photography, whether hang gliding or KAP.  With the size and weight of a compact, but  APS-C sized Foveon sensor and excellent Sigma fixed 28mm (equivalent) wide angle lens it hits all the marks while it's shortcomings -  low light noise and s-l-o-w processor - are tolerable for this application.

However, there is one serious shortcoming - no external shutter release.  (Why Sigma)?

Yes, it can be done with a servo but for hang gliding at least this is hardly ideal being fragile,  power hungry and quite an extra lump of drag inducing stuff...

clunky servo release
Never did work that well actually.

HOWEVER...   it turns out that it is possible to hack this camera with an external electronic shutter release.  It's fiddly and requires some experience with surface mount electronics, but does NOT require the camera be extensively dismantled.

So, with the usual disclaimers that this will OF COURSE invalidate your  warranty AND could irreparably wreck your camera even if you do know what you are doing AND could be partially or totally duff information - here's how its done:

 Take out the battery and observe ESD precautions.  6 screws gets the rear cover off cleanly exposing a circuit board.  Top right you see two SMD resistors.  These give you access to the 1/2 press focus lock and full press shutter release switch circuits.  If you can't imagine soldering something that small, STOP and get help.

rear cover off
resistors highlighted

The right resistor connects to 1/2 press switch, the left to full press.   Connecting the bottom end of either resistor to GND via a 50R pull down will trigger the appropriate response from the camera.  (I only need to operate the camera in manual focus mode remotely, so made a connection to the left resistor only).

wiring to connector
The enamalled wire is held in pace with a cyanoacrylate adhesive and brought to a tiny 2 pin connector installed adjacent to the USB socket.  A handy zero-ohm link provides the GND connection.

external trigger connector
The wireless reciever and auto trigger are another couple of hardware hacks...

DP1s with Ricoh DW-6 & external wireless trigger
I haven't really put it through it's paces yet, but here's an early attempt, paired with a Ricoh DW-6 wide angle lens.   A rather odd angle but shows promise I think...

Airborne C2 over Laragne Charbre