Yoshizen's Blog

Camera Hack — or Lens Hack (by a Hacksaw !)

I’ve been kept saying that the Canon DSLR system is the most versatile, flexible

camera system known to us —– though, there is a funny contradiction within their

own system. — Among their DSLR lenses  there is the EF-S series which was

designed to be used on clopped format camera body such as a cheap EOS Kiss.

 As the EF-S lens’ image circle was smaller, lens could be made smaller, lighter 

 therefore cheaper = in theory, if such lens was used on the full frame body, the

image will be somewhat a rounded smaller image though in practice, it wouldn’t 

be happened because the protruded bottom of the EF-S lens was blocked by the

camera’s mirror box. 


Yet still, with an “intention”, I got a discarded EF-S 18~55mm II lens.  

—– My intention was to modify the lens to create “Soft image by Focus-shift” = 

Drive the AF motor during the exposure.  

With a Hacker like hack, it should be hacked into the 5D camera’s OS and hi-jack

the AF motor’s control though, the risk is, completely spoil the £3000 camera

of which the Canon will only laugh at me and refuse to repair the poor camera.

(We can find the code to hack in the camera’s OS in the Net though, the matter is 

not just drive the motor.  There will be a feedback from Encoder, position sensor etc, 

= With a conflict, soon camera tend to stop work with an Error signal.) 

What so ever, I need to mount this lens to my 5D body to test the feasibility.

EFS F'Shift-1-322-001

So, simply, I cut the protruding part of the lens mount. (Photo above)  

Now the lens could be mounted on the 5D body (anyhow, everything is in the

manual mode) = (This is THE most Canon hated kind of the practice ! ) =

the test shot of the EF-S 18~55mm on my 5D body was like those.

EFS F'Shift-2-323-001

= (Photo above Left) On 18mm setting, the bottom of the lens which was 

protruding as well was hit by the mirror and only a top part (in the Camera, 

it was a bottom part) of the image was recorded,  then an Error message 

was appeared and the camera stopped working.  🙂    

Still, somewhere 20mm position, as the lens doesn’t penetrate too deep,

 the captured image was like this. (Photo above Right)  

EFS F'Shift-3-324-001

And on the 24mm (25mm would be better), no cut-off of the corners.

(Photo above Left)  (Photo above Right was at 55mm)

= It’s mean, this lens could work as a 24mm~55mm zoom lens on full frame

body though, what was a point to have such a hassle while not so expensive

proper lens is widely available (not mention secondhand) is a good question. 

Yet still, to test “Focus-shift” experiment, this is the perfect lens for me

 —– which costed almost nothing.  🙂

(Another more expensive lens is using more complexed motor, such as an

Ultrasonic Motor, but this lens’ DC motor is the easiest to modify.)

EFS F'Shift-4-325-001

The circuit is taking a signal of the Shutter Open from the Flash Synchro Socket,

then start the AF motor, hence the “Focus-Shift”.

— So far this analog approach is working —> Make it to a compact package 

and to have a field test would be a next step.  

Then, whether worthwhile picture could be created or not is a different story.

(Never mind, it took 6 years for the photos of my “Yoshi-Handy” were recognized.)


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