DIY Mod: Variable length OC-E3 the cheap and easy way.

This is my DIY guide to making your own cheap and reliable variable length OC-E2 or OC-E3 cable.

Firstly some background: I am not electrically trained beyond taking a few classes in electronics for my school certificate ~10 years ago. This involves nothing more complex than cutting wires and poking a soldering iron at some wires. I make no claims to have done this as well as it could have been done nor as neatly as it could have been done, however... most people who are interested in this I imagine have a level of skill equitable to mine so I think it's a good example of what you can do with nothing more than basic knowledge and skills.

Why would you do it? Allowing you to use your sole flash as an off-camera flash with a 100% reliable connection - including ETTL, if that's your cup of tea. It's not wireless like Poverty Wizards but it'll work every time and with enough slack I don't find the cable inconveniencing, so I know which one I'd rather work with.

With newer cameras like my 1D III and other models (40D onwards? I don't recall precisely) you can control the flash using the camera's controls. Not a big deal if the flash is right there on your hotshoe. However... using a very long OC-E3 you can then put your master flash in your lighting setup while still using it to trigger the other flashes, rather than wasting its light output on top of your camera (assuming you're not using some on-axis light). Given that it's cheaper and offers more control than a ST-E2... you get everything a 580EX can do. Also opens up some possibilities of where you can be and still trigger your flashes using Canon's own triggering system.

Being able to change the length as required is also handy... no point in lugging 10m of cable around for when you only want 2 or 3. Also, Cat5 cable is cheap. Very cheap. You break it on a job, lose it, have your dog eat it, whatever... no big deal to replace.

Items used: Soldering iron (mine cost $10 or so), solder, 1m Cat5 cable which can be had for <$3 in most places... and something to cut with. I used a Swiss Army Knife, anything will do.

Skill required: Essentially none. To be able to do simple soldering... I picked up a soldering iron a few times in high school - 10 years ago now. Not once since until this mod, so if I can do it anyone can.

I'm linking to the photos for now, will come back and embed them in case the source links change.

Onwards to the good bits!


First, take your OC-E3 and take out the screws in the underside of both ends.

What you'll see there is something like this:

Detail shot of the camera end:

Now, take your cat5 cable and cut it wherever you want the joins to be. I like a 1m cable cut in half... means that the joins hang conveniently for me. YMMV.

Inside you'll see eight wires. Since we only need six you can double up the ground and the center pin, which seems to make the most sense to me. The original ground wire is particularly large in comparison to the others and is also shielded differently.

Before you solder anything cut off the rubber grommet bit that sits inside the case on either end:

Flash end soldered - length of time taken depends on how competent you are with a soldering iron. I'm not particularly skilled so it took probably twenty minutes of mucking around. For anyone who actually can solder I apologise in advance for what's probably an offensive image.

Flash end completed and screwed back in:

All soldered in. I found that this end is much easier to do than the other one... more room to work in. You need to cut back much more of the black part of the Cat5 cable to get it to loop through the metal piece.

Using just the two short pieces:

And that's it, really. All in all it takes me a couple of hours to do, anyone with skill ought to knock it over in much less. I've got a cut OC-E2 to do later on but I imagine it's going to be fairly similar...

Any questions, comments, suggestions welcomed...

Jim,

Amazing! The photos couldn't be more self-explanatory. But the cat is still saying, "What the f*%k?!"

I may have to get my dad to try this... I'm not confident enough at all and he's been rewiring a bit of electricals lately so he might be in a bit of form for it

Do you have the Canon OC-E3 or is it an off brand? I've got the YongNuo one off eBay but I can't imagine it being too different to yours if it's a Canon.

tvphotog wrote in post #8016945
Jim,

Amazing! The photos couldn't be more self-explanatory. But the cat is still saying, "What the f*%k?!"

She may not be a DIY fan, perhaps... or maybe she's curious

The Moose wrote in post #8016975
I may have to get my dad to try this... I'm not confident enough at all and he's been rewiring a bit of electricals lately so he might be in a bit of form for it

Do you have the Canon OC-E3 or is it an off brand? I've got the YongNuo one off eBay but I can't imagine it being too different to yours if it's a Canon.

Genuine. If you do give it a go post a photo in the thread or even if you just open it up and take a photo... I'd be interested to see how different they are or aren't inside.

^^^ Good detailed DIY

Look here also

https://photography-on-the.net/forum/showthre​ad.php?t=123662

You should Add yours to that Thread. My DIY is on the Last page of the Original Thread using Cat 5 also .