Sync Cord

[kye_brown1]

<p>I have seen some photogs use a sync cord for hot shoe mounted flash. What is the benefit of this and if I purchase one do I buy it for the type of flash I use or the camera I have Nikon d70? Thanks</p>

[Alan Marcus]

<p>If you drive or ride in a car at night, likely you have seen animals caught in the headlights. Often the eyes of the animal seem to glow intensely green. What you have witnessed is due to the fact that driver and passenger are on axis with the car’s headlights. What I am saying is you are seated directly over and in line with the headlight beam.<br>

Now certain geometric shapes reflect light directly back at the light source. This is the principle behind the brilliant cut diamond. Modern highway signs utilize the principle by means of paint with imbedded glass beads.<br>

What does this have to do with your question?<br>

Seems animal eyes and human eyes naturally have this shape. They reflect light backwards directly towards the light source. Now if the flash is mounted in close proximity to the camera lens, the momentary flash will be reflected backwards and cause what we call “redeye”.<br>

Seems the light transverses the eye, hits the blood rich retina and returns as a red blaze. A camera with built-in-flash is highly likely to yield redeye because the flash in nearly on axis with the lens. The countermeasure is to add separation between flash and lens.<br>

Experienced photographers hold the flash at arms length. This accomplished two things. 1. Reduces the likelihood of redeye. 2. Flash-lens separation yields a shadow that gives an illusion of depth not present when the flash is on axis.<br>

To accomplish the flash must be remote so a long synchronization cable is needed to interconnect camera to flash.<br>

Other countermeasures: Some cameras pre-flash a split second before the main flash flashes. The idea is to causes the human eye iris to contract (get tiny) as this reduces the likelihood of redeye.<br>

Footnote: Nocturnal animals have a retina colored with a pigment that increases night vision. This pigment is greenish/yellowish. The human eye also has such a pigment called rhodopsin also called visual purple. Our retina generates this dye and the ISO of the human eye increases a thousand fold due to its being there. It takes an hour or so for us to make the dye and fully dark adapt. Condition red on a ship does not signify danger on a ship. Ships go red to allow sailors about to go on watch at night, time to pre-adapt by generating rhodopsin so when they go on deck at night they are pre-dark adapted. Rhodopsin bleaches away when we move into the light. The eye bathed in rhodopsin can be so light sensitive that we experience pain coming out of a darkened picture show into the light.</p>

[andrewg_ny]

<p>In addition to helping manage redeye, moving the flash off camera helps avoid harsh shadows visible just behind the subject and makes the subject look less 'flat' by giving the light a little more directionality. This also allows the light to come from above even if the camera is rotated into portrait orientation.</p>

<p>As for the cord, it depends on the camera, flash, and what protocol they are communicating with. For example, if you're using Nikon body with a nikon dedicated flash, you want to make sure that your sync cable allows full communication between body & flash so that you don't lose full i-TTL automation. Some flashes have a port for a cable, or others require a hotshoe adapter where a shoe for the flash has a socket for the cable.</p>

[hjoseph7]

<p>"What is the benefit of this and if I purchase one do I buy it for the type of flash I use or the camera I have Nikon d70? Thanks"<br>

I think Alan explained the purpose thouroughly enough. If your flash is a dedicated flash, meaning some of the functions such a TTL, Auto aperture, won't work on any other camera than the one it is dedicated too and you want all those functions to keep working while it is connected to a sync cord, then you need a dedicated sync cord(expensive).<br>

If you have a non dedicated flash, or you don't care wether the functions work or not with your sync cord, then you can get a non-dedicated syncord(cheap, can be used as a backup). </p>

[frank_skomial]

<p>For your D70 and Nikon iTTL/CLS compatible flash ( I presume you have one like that ?), you need SC29 flash extension cord that has focus assist light much better than anything else. You could also use SC28 that does not provide separate focus assist light. These 2 cords are Nikon TTL compatible cords, that is compatible with the new iTTL system used by your camera.</p>

<p>Perhaps any other sync cord will loose iTTL flash automation? May be some older TTL Nikon flash extender cord will work too ?</p>

<p>Since your D70 popup built-in flash can act as CLS commander for remote CLS flashes, chances are that you do not need any cord at all ? What flash do you have ?</p>

<p>I believe only SB400 from Nikon line, is not CLS compatible and will not operate as a remote CLS flash. SB600,800,900 - all can be commanded wirelessly from D70 commander flash, no wires needed, subject to CLS system limitations.</p>

<p>And of course, all funstions of your CLS/iTTL flash will operate if you use the Nikon TTL compatible flash extension cord. (e.g SC29).</p>

[craig_shearman1]

<p>There are two types of sync cords. Almost all flashes whether totally manual or super sophisticated can use the standard PC cord that has been around more more than 50 years. This consists of a male PC connector on the camera end, and most higher-end cameras have a matching female PC socket on the camera body. This connector is standardized and does not vary from one camera brand to the next. The flash end of the cord usually has a proprietary connector, so you have to be sure the cord matches your flash. The PC cord is a simple two-wire connection that merely closely an electrical contact to fire the flash when you push the shutter release on the camera. The other type of cord is for dedicated TTL flashes. It has a female hot shoe (just like the shot shoe on top of your camera) on the flash end, and a male hot shoe (just like the hot shoe on the bottom of your flash) on the camera end. The cord is multi-wire and the connectors have multi pins. In addition to firing the flash, it transmits all of the sophisticated exposure information that normally goes through the hot shoe, but allows the flash to be held off to the site in order to get better lighting. If you are only go to use your flash on manual, all you need is the standard PC cord. If you want to use the automated features (TTL etc rather than just simple autoflash) you will need the hotshoe type cord.</p>

[jim_momary]

<p>Curiously, Nikon's recent SB600 does not have a pc synch terminal.<br>

But, I too use the SC29 when not wanting to be wireless and 'off camera".<br>

Jim</p>

[frank_skomial]

<p>... and the D70 does not have a PC sync socket. If you have to use a standard cord, e.g. a 50 years old cord, and give up flash iTTL automation, you need to get Nikon AS-15 for your D70 that provides PC sync socket, but looses iTTL. (AS=Accessory Shoe). AS-15 costs about $15 and is a saviour for D70 for use of other non-Nikon brand flashes. There are generic Hot shoe to PC converter adapters at even lower cost.</p>

<p>If you plug anything into D70 hot shoe, most likely your D70 built-in flash will not swing up to fully vertical position, and possibly the internal camera flash will get disabled, if any external trigger voltage is detected in the camera hot shoe.</p>

<p> </p>

[charlesheckel]

<p>There's also a trick called "feathering." When you have a group with subjects near your flash and others further from it, aiming the flash at the further subjects and putting the near subjects at the edge of the field of illumination can give even illumination to all.</p>