Disassembly of 5D mark III and reconfiguring
It’s pretty difficult process to perform any modification on commercially available cameras due to its tightly designed body with its specific parts design.
Canon’s 5D Mark III has quite huge M/B (Main Board) which is located very close to CMOS sensor with little spaces to do any modification so we have concluded that it will be impossible to install onboard sensor cooling modules within the existing camera housing. However, we noticed that the cable from M/B to CMOS is long enough to accommodate re-locating CMOS to outside of the camera body and by this way, installing cooling module could be possible.
Re-arrangement of the parts are eventually finalized to slimmer squared outer design housing with front mounted lens adopter and cooling module on the back of the body.
A shutter function was removed due to the motor, solenoid, gearbox, shutter blade and circuit boards, etc. that were quite big in size so it was not possible to accommodate the one-touch type 2-inch Drop-in filter holder on the front of CMOS.
A shutter module was re-located to the left side empty space of CMOS after a shutter blade unite removal. The shutter is still there functioning but not capable to control the amount of the light that reaches the image sensor.
The shutter speed of the camera is controlled only through the Bulb mode and the exposure time is controlled per second unit via PC software like Timer Release or EOS Utility.
The camera’s main board is designed to constantly monitor the main components’ functionality using the various sensors. It will immediately display an error code and terminate its operation if any mal-functioning area is detected.
These main components are still expecting the mirror box operating motor and the shutter, therefore, even when the mirror box is removed and the shutter functionality is not in use they should be included to the camera to ensure the normal operation of the camera.
But other parts including the top cover, LCD display, CF memory card, pent prism, AF sensor, etc. got removed as they do not affect the Bulb mode and the image saving.