# Canon EOS

## Hacks

Hand-made trigger for 350D & other Canon models (look for "C6" here:
File:Declencheur.jpg
The external trigger is composed of a jack 2.5mm, three wires, an on/off switch and a push button
Shortcut of ground and right (the middle ring) is equivalent to half-press, here wired to a simple on/off switch which provides the housing
Shortcut of ground and left (the tip) is equivalent to full press, here wired to a simple red push button

### AV to stereo cable for 5D Mark II

The 5D has an AV output connector accepting a TRRS 3.5mm jack.
With Magic Lantern you can use it to plug a headphone and get the sound feedback directly while recording a movie, nice!
But you can't just plug the headphone into the camera, you would get only sound on the left ear and, worse, you would be busy short-cutting Ground and Right signals!

On the Canon side, the AV port is a female 3.5mm TRRS jack, TRRS means it has 4 connectors where T=tip, R=ring (so two rings), S=sleeve.
On the headphone side, it's a simple stereo 3.5mm TRS jack.

We have:

canon               stereo jack
=====               ===========
T left              T left
R video             R right
R common            S common
S right             S common


I've shown the TRS as TRSS to show that physically the second ring of a TRRS meets the sleeve of a TRS.

To build an adapter, I bought a cheap 50cm 3.5mm jack TRRS cable (so a TRRS male at one end and a TRRS female at the other end). I didn't want any adapter cable because there is a high chance it's not properly wired. Even the popular TRRS to RCA have a great chance to have the ground on the TRRS sleeve which means you'll get the Right signal on all three cinches instead of the Ground. If you use a TRRS-RCA make sure to use the one provided with your EOS!! But that solution is bulky and we need an additional RCA(male)-TRS(female) to hook a headphone. With a TRRS extension cable, we've full control.

Cut the cable somewhere and check its color code. Here also electrically check it, don't make any assumption on the color codes! Mine was like this (with color conventions, to show you it's arbitrary and you can't trust it):

T naked cable  (usually naked=ground)
R white cable  (usually white=left)
R red cable    (usually red=right)
S yellow cable (usually yellow=video)


We want to wire left-left, right-right and common-common. We'll leave the video signal from EOS disconnected. As common on the TRS is wide, we'll connect both R&S of the female connector of the cable to the common.

So it will look like this:

canon       cable           stereo jack
=====       ============    ===========
T left      T----------T    T left

R video     R     +----R    R right
/
R common    R---/--+---R    S common
/    \
S right     S-+      +-S


My cable just before soldering, with the thermo retractile tubes ready: (colors of your cable may be different, beware!!)

With this cable you can also use a mobile headset with TRRS & Mic, it won't hurt (and obviously the Mic won't be used by the camera). It would look like this:

canon       cable           OMTP jack
=====       ============    =========
T left      T----------T    T left

R video     R     +----R    R right
/
R common    R---/--+---R    R mic
/    \
S right     S-+      +-S    S common


Even an iPhone headset should work:

canon       cable           CTIA jack
=====       ============    =========
T left      T----------T    T left

R video     R     +----R    R right
/
R common    R---/--+---R    R common
/    \
S right     S-+      +-S    S mic


## Notes

I was wondering why in bulk mode over 30s the camera was busy after the shot for about the same time.