Lighting Tip: Neuter Your SC-17

Nikon's SC-17 off-camera TTL flash cord is a great little addition to your kit, and you do not even have to be a Nikon shooter to use it. They are so cheap, I have several. And I recently put one under the knife.

Keep reading for he how and the why.

The SC-17 is basically an extension cord for your hot shoe that carries all of the various TTL connections. A flash, connected to your TTL-enabled Nikon via an SC-17 cord, may as well be connected to your hot shoe as far as the signals are concerned.

But the fact that it is off camera allows you to get better light, of course. I have written about this earlier, when talking about the strobe on a rope technique.

No longer manufactured, the SC-17 cords have since been replaced by the new (longer) SC-28, and the more expensive SC-29, which includes an AF-assist light. I like the SC-17 because you can find them on eBay pretty cheaply now.

You can link up to three SC-17s and still retain all of the TTL functions. Or if you are handy, you can splice a CAT-5 wire in there and run it about 50 feet, still keeping TTL.

But TTL is usually not what I use it for. In fact, I am trying to kill the TTL stuff for a specific reason. When shooting both with my Canon G9 and with the Nikon D70s, the trick to getting high sync speeds is to fool the camera into thinking there is no TTL flash connected.

If the camera senses a TTL flash, it will lock the sync at a max of 1/500th of a sec. Which is not what we want. So, we want a dumb, hot-shot-based sync cord to fool the camera into thinking there is not a fancy, TTL flash attached.

To do this, we will unscrew the little screws at the camera mount end of the cord and snip a few wires. It's easy, really, so don't worry about having to be a surgeon or an electronics wiz.

When you open the case at the camera and, you'll see five wires. The two wires you want to SAVE are:

1. The wire that connects to the big center post in the bottom, and
2. The wire that connects to the fail on the side.

These two wires constitute a "dumb" sync circuit. These are the two you DO NOT want to snip. The other three wires carry TTL info. Snip them and the TTL connection goes away. This also makes the SC-17 into a very good little hot-shoe-based sync cord for any brand of a camera with a hot shoe. No proprietary Nikon circuitry to worry about, either.

And for ultra-high sync stuff, this is better than using a Pocket WIzard. Because the electronics in the PW actually self-limit your sync to about 1/1000th of a sec. Not so a dumbed-down SC-17 (or a straight PC cord, for that matter.)

Some have correctly pointed out that an un-neutered SC-17 will work just fine as a dumb sync cord on a Canon. Bu I prefer to knock out those TTL circuits all the same, just in case there is some weird crosstalk going on that might harm the camera. Also, I use the cord for the Nikon D70s for the same reason. So it needs to be snipped for that reason, too.

If you do not want to ship your cord, you can always tape off the contacts at either the camera or flash connection point. But the cords are so cheap I prefer to just keep a snipped one along with my straight ones.

For multi-light setups, I will cord one hi-speed-sync flash and slave the others for multiple light setups in hi-sync situations.

Another thing: If you keep several SC-17s in your bag, you can chain the TTL ones together for a full TTL cord. But if you introduce one neutered cord into the chain, the whole chain goes non-TTL.

So, I keep three SC-17s in my kit -- two smart and the other one neutered. This gets me the best of both worlds when I am cording an off-camera flash.

Related posts:

:: How-To: Strobe on a Rope ::
:: Search SC-17 on Strobist ::


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Blogger carlos said...

I'm sure you meant that sc-17's were inexpensive...... The strobist effect will take care of that little oversight soon enough....

May 02, 2008 12:13 AM  
Anonymous Craig said...

Good tip. Though wouldn't putting some tape over the unwanted contacts provide the same solution with less work? All we're trying to do is not allow a circuit, no?

May 02, 2008 12:21 AM  
Anonymous Anil said...

I have a SC28 which I opened up to do the snip snip.
There is a small printed board at the bottom of the chamber, and I cannot tell which wire goes to which terminal - except of course the thick black wire which connects to the side plate.
there are 4 other wires: blue, white, yellow and red. Which one connected to the center-post? can anyone assist please? I guess I could check it with a continuity-meter but I don’t have one handy just now.....

May 02, 2008 1:54 AM  
Anonymous Bob said...

I have a suggestion for anyone who has extended an SC-17 with connectors in the middle, as I did. Make up a length of cable with only two contacts so you kill the TTL only when the extension is in place and you don't have to lose TTL on the SC-17 all the time.

You could also put a switch in the cable to select the neutered mode.

May 02, 2008 2:46 AM  
Blogger Ron ( Southern Wedding Photography ) said...

Can you elaborate on the extension cord wiring? Do you have pics?

May 02, 2008 5:27 AM  
Blogger Matt said...

Is it possible to just us a Nikon AS-15 Hot Shoe-PC adapter (or similar) and the PC cords from the lighting 101 tutorials? No surgery would be required for this solutions and the cable could be whatever length you want to make it.

May 02, 2008 7:23 AM  
Anonymous Anonymous said...

Well they WERE inexpensive! You wouldn't be putting a few SB-17's on Ebay any time soon, would you? ;)

May 02, 2008 8:07 AM  
Blogger nick.flick said...

what about a normal pc sync cord and 2 hotshoe adaptors,It's exactly the same thing.

May 02, 2008 8:07 AM  
Anonymous Anonymous said...

I lengthened an SC-17 by putting the coils in hot water (just below boiling - be careful). Take the coils out of the water and pull them straight - voila a straight cord that's about 3 times the length of the coiled one. Repeat the soak in hot water process until it lays completely straight.
Don't scald yourself and don't put the connector ends in the water!

This way there's no soldering required.

May 02, 2008 8:09 AM  
Blogger Ken said...

DH said:
"Because the electronics in the PW actually self-limit your sync to about 1/1000th of a sec."

My testing (which could be flawed) shows otherwise.

Using a Nikon D200 (Auto FP on), SB800 (manual mode, 1/128 power), Pocket Wizard Plus II and Hensel Integra 500 strobes, I was able to sync at 1/8000. Smooth clean light top to bottom. EXIF data confirms 1/8000 sec.

Certainly, there may be a delay, but with the Hensels, there was no effective limitation. It worked at all power settings. This suggests that the Hensel has a long flash duration and is unaffected by any PW delay.

Perhaps the newer Pocket Wizards are quicker, or I have have that lucky combination of gear that works. Is anyone else able to sync this fast?

May 02, 2008 9:44 AM  
Anonymous Thomas Boydston said...

Just thought I'd post my (bad) experience with this.

I opted for this a DAY before this post came out so I just googled up a diagram/chart/schematic of the SC-17 and found out which wires and terminals contributed to the TTL nonsense.

Opening the two chambers can be a bit difficult since the screws were probably what made the threads so it's a bit snug. I SEVERLY stripped one screw and the others gave me a nasty blister (cheap screwdriver made of all metal, my fault).

Once I got them open I had to leave the office and head home so I put it in my camera bag. When it's all together the cord is fairly impervious to harm, but once (for some reason) when the bottom casings come off, a butterfly landing on a piece will cause it to bend and snap in places. I have one casing top that's really, really, really bent and the piece that screws into my hotshoe has a corner tearing off. I'll just remove it and force them to screw back together and hope for the best.

Also, the ground wire (the one wire that goes to the side that you shouldn't snip) is attached to a metal, 3-sided piece that for the life of me I can't figure out how to set back into the rig.

So now my "neutered" SC-17 is in warped, broken pieces on my dorm desk waiting for a bit more TLC.

So just make sure you do it all in one sitting and have the right tools and you should be good.


May 02, 2008 11:17 AM  
Anonymous Ben Roberts said...

So without having cut up an SC-17 myself it sounds as though for the neutered version you could snip the two wires in question, put a male mini monoplug on one end and a female on the other and have a cord that could have extensions inserted into the middle as needed.

Don't want a long cord? Just plug the two ends into one another. Add a few mono cords of varying lengths to your kit (or use the ones you already have) and get instant extension. Sans PC plug hatefulness.

Intelligent use of velcro at the plug connections could stop them unplugging from one another in use.

May 02, 2008 11:48 AM  
Blogger Chuck said...

My two cents on the need to hack or trick the G9.
My experience is that i don't need to trick the camera at all, whether I have the flash on the hotshoe, off camera via canon off camera cord or via pocket wizard.
I can synch at the high end (F8 @ 1/2500) with a 550EX or an SB26 on the hotshoe or cord.
I have also synched around 1/1000 with my pocket wizards without needing to "trick" the camera.
I added a couple pics to my G9 flickr set as examples.

May 02, 2008 12:02 PM  
Blogger Barnacle said...

i am going to test this right now with my D100 and a paramount cord. seems like the same thing to me?
i won't be snipping my SC17 as i like the TTL feature, but if i did, i like what BOB sais about adding a couple switches in the middle allowing for both dumb and TTL!

May 02, 2008 12:05 PM  
Anonymous Anonymous said...

Im using sony slr with minolta flash (2 5600 hsd's) and as most know this has a non standard hot shoe and the flash has no pc sync, but otherwise excellent flash units. the wireless control is line of sight only and in bright light wont work.

I dont have a schematic and the 5 ft extension cable from sony is $60 per cable (Sony doesnt recommend daisy chaining them together, but cat 5 isnt $12 a foot either and another benjamin for the hot shoe adaptor to use two flashes this way...

Do you know of a link to anyone that has hacked the minolta cable in a simular manner like you described with some cat 5 cable? i really couldnt find anything on the web as far as an "instructable" or something specific for the minolta hot shoe setup, specifically the pin diagram.. hope someone can help..


May 02, 2008 12:32 PM  
Anonymous Anonymous said...

Set the sb800 to manual so there is no feedback to the g9 -- no wire snipping and you can use ttl on your nikons.

May 02, 2008 12:57 PM  
Blogger Geoffrey said...

I can confirm what Ken posted. I've been aware of the this hack but just tried it. D200 (Auto FP on), SB800 (manual mode, 1/128 power), Pocket Wizard Plus II, and Lumedyne @ 50, 100 or 200 ws, no banding! Woo Hoo, goodbye Mr. Sun.

May 02, 2008 1:24 PM  
Anonymous Anonymous said...

Yeah.....but um I am trying to visualize it but its not working so please please post a pic. showing how because I am the "Stereotypical" women when it comes to cuting wires. thanks

May 02, 2008 2:12 PM  
Blogger Admin said...

As probably said, you can simply place a small piece of electrical tape over the 4 pin plates on the cameras shoe, bobs your uncle!

May 02, 2008 2:25 PM  
OpenID apartmentseven said...

I was also going to mention either tape or nail polish to cover the unused contacts, to keep all the connections in tact in case TTL is necessary later. If nail polish is used, 70% rubbing alcohol will take it off without fading the plastics of the unit.

May 02, 2008 3:09 PM  
Anonymous Andrew C said...

I have linked up to 5 sc17 cords in the past, on a f90x Nikon camera with a 300mm lens. I used an external baterie pack with the flash for quick recharging.I don't know if this allowed me to use more than three cords togeather.Speaking with a Nikon rep on the phone at therr 1 800 number, he was quit surprised and had never herd of doin this. Were talking a few years back now. You need to be sure the linked cables are all fully conected. The ttl allows you to shoot while the cloud cover changes.

May 02, 2008 3:46 PM  
Anonymous The Dude said...

I'm with Matt on this one. All this Dr Kildare stuff is just a little too much for me. My motto. Keep it simple, with a Nikon AS-15 Hot Shoe-PC adapter and everyday PC cords. The humble PC cords were born dumb in the first place. They are cheap as chips and no brain surgery required. Better still, they work!

Today I was quoted £100 for a second hand Nikon SB-28 to go with my newly acquired Canon G7. The credit crunch strikes again.

May 02, 2008 4:32 PM  
Blogger LP said...

O.K. So you have 3 SC-17's in your bag, two full TTL. What "coding" method do YOU use to know which one is neutered?

May 02, 2008 7:24 PM  
Anonymous Anonymous said...

And for us Canon users...?

Would be really helpful to either show us a comparable fix on these posts or to say it can't be done/doesn't relate.

May 02, 2008 8:58 PM  
Blogger Steve Hebert said...

Any ideas on how to synch a vivitar 283 and a sony cybershot h7?
Steve Hebert

May 02, 2008 11:14 PM  
Blogger Patrick said...

Yeah it's pretty crazy that you can do this FP hack where you fool the camera into thinking it's in FP mode and then simply blasting another off camera flash at full power.

I just shot an SB800 up to 1/2500th of a second using this method. Would have been really handy when I was shooting outside in bright sun a few days ago.

May 03, 2008 3:07 AM  
Blogger jlc said...

An alternate source is KEH - which has them in the $30 range. Amazon has them used every now and then - picked one up for $25.00

May 03, 2008 4:06 PM  
Anonymous The Dude said...

For us based here in the UK, Photomart in Walthamstow, East London are selling these dumb extension leads for £9.45p. each.

May 04, 2008 9:48 AM  
Anonymous bill said...

can you neuter your SC-17 (or use the AS15 PC adapter) and still use the SB800 as a Master in the CLS / AWL configuration?

May 04, 2008 7:42 PM  
Anonymous drh said...

Am I wrong in assuming that this high speed sync works best with only 3 Nikon DSLR models. Only the D70, D70s, and D40 (not D40x) have the combination electronic/mechanical shutter. Comments anyone?

May 04, 2008 10:20 PM  
Blogger jacob said...

lotsa usefull hot shoe cords from paramount cords co.

May 05, 2008 1:36 PM  
Anonymous Noah said...

I tried my D200 and D3 and it was still cutting off most of my frame at anything over 1/400 of a second. Am I doing something wrong?

May 06, 2008 11:24 PM  
Blogger jacob said...

to noah most likely you are going beyond the flash synch speed of the camera

you might be able to get high speed shutter synch with the sb-800 flash .. but the symptom you mention sounds like too high of a synch speed

May 07, 2008 7:31 AM  
Blogger mtreinik said...

If you want to keep your SC-17 intact, the TTL cord can be dumbed down by putting a Hama Univeral hot shoe adapter between the hot shoe of the camera and the SC-17. That will only conduct the signal from the center pin on the camera to the center pin of the cord.

That saves some room in the camera bag, since instead of an extra cord you only need to carry a small adapter.

May 09, 2008 2:19 AM  
Blogger Antonio said...

The FP function on my sb600 will not communicate with My D200 using a neutered sc17.

May 09, 2008 5:07 PM  
Blogger Antonio said...

Noah the neutered cord will not allow the FP function to work on the D200,
if you solder the wires back, and set your flash sync on the D200 to (250 auto FP) you will be able to set the flash to manual and fully expose in
high shutter speeds. This is assuming you have a SB600 or SB800.

May 09, 2008 5:23 PM  
Anonymous Graham said...

Nice quick hack, works a treat - I used an Ebay SC-28 (longer, better hotshoe lock and now cheaper than an SC-17 thanks to Strobist lol) 30 seconds work and I can get sync at 1/8000 on the D70 and 1/2000 on the G9 - thanks David!

May 14, 2008 6:42 PM  
Anonymous AlexJB said...

wow, some of those hot shoe extender cables are over $150 !!

for those who were (like me) thinking of using this hack to split the SC-17 to run two flashes, and then realized that they would still need two SC-17s to cannibalize ($50+ each), consider this cable:

a hot shoe TTL splitter. i'm planning to get one and then extend each one...

keep in mind that the nikon SB-600 doesn't have any cable connectors (PC or nikon) other than the hotshoe, so PC sync options are out without yet another adapter.

May 22, 2008 10:14 AM  
Blogger Troy said...

OK, i am going on record right here and copyrighting the following idea, anybody out there making money off this, just send it straight to me ;)

Instead of just snipping your ttl wires, simple run them through a toggle switch. this requires a little soldering but no biggy. now you have a supersync cord(© 2008 Troy Mamer) that, not only can you run in full manual "dumb" mode, but, at the flip of a switch, still benefit from all the ttl you can handle.

June 06, 2008 1:29 PM  
Anonymous Alexander said...

If you have an older SB-24 or SB-28 (that don't do TTL with the newer cameras), as many strobist do, you can sync these units with a D40 up to 1/4000s. On camera or off camera on a TTL cord - without any snipping. This way, you can use your TTL-flash via cable and do high speed sync with the non-TTL flash in M or A flash mode with the same unaltered cable.

June 23, 2008 10:06 AM  
Blogger Robert said...

My Rebel D manual sais that Canon E series speedlights wont work w/ it in manual mode. mine only has automatic mode so If i disable the ttl w/ one of these tricks does that meen that it will now work?

February 26, 2010 1:23 PM  
Blogger rodrigov said...

Hi, could you tell me what is the right place of each TTL wire if i want to put them back one day?

March 02, 2010 9:56 PM  

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