jerryc41 Loc: Catskill Mts of NY

If I understand correctly, this unit will fire a flash that is connected to it when it sees the light from the flash that is set off by the camera.

The description says it will be triggered by the Master flash. Would the pop-up flash on the camera be the master?

Robert Graybeal Loc: Myrtle Beach

What camera are you using?
Some of the Canons have all that built into their system.

jerryc41 Loc: Catskill Mts of NY

D7000, D70

Frank T Loc: New York, NY

The slave unit you showed will trigger the flash with the pop up flash as long as you have line of site. It will not however communicate with the camera so you'll have to shoot in manual.

MT Shooter Loc: Montana

Your D7000 has flash "Commander" mode which will trip several remote flashes, I have tripped up to 4 at once with mine. And Nikon CLS system flashes will operate as remote slaves in iTTL mode even.

jerryc41 Loc: Catskill Mts of NY

I'll probably have to set up the camera's flash to be the master.

jerryc41 Loc: Catskill Mts of NY

OK. I'll have to take a look at the manual.

GoofyNewfie Loc: Kansas City

Jerry,
What flash do you intend to use on the slave sensor?

Pepper Loc: Planet Earth Country USA

What are you using for a slave?

CaptainC Loc: Colorado, south of Denver

This will not work with the Nikon CLS/TTL system. The preflash will fire this and not the flash used for exposure. If you use your popup in Commander Mode and set to "M" for manual, it has a good chance of working.

Rumaweigh Loc: Richmond VA USA

Perhaps. Depends on the characteristics of the pop up. Some camera pop-ups do a quick pre-flash to get exposure which would trigger the slave. I have found radio triggers to be more reliable than the optical slaves.

jerryc41 Loc: Catskill Mts of NY

SB-400 and Sunpak 555

bobmcculloch Loc: NYC, NY

I think it is supposed to, I've never had much luck with that kind of slave though, best I used was a borrowed radio wave sync unit. Bob.

jerryc41 Loc: Catskill Mts of NY

I've used extension cords, but I thought wireless might be worth a try.

dpullum Loc: Tampa Florida

JerryC41: I think that these people have been confused by Nikon Flashes shot from Canons!! or have inhaled the smoke from Blitzlichtpulver (flash powder, 1884 like in old movies.)

The unit you show is a simple minded slave unit, and does not think ahead and confuses the camera by firing at a preflash, either, red-eye, available-light reader (a preflash to see how much exposure or power of flash to adjust). The slave flash will actually darken the exposure, because the camera will think the slave is the constant "bright-sun" shining.

What you need is flash like the one that actually is controlled by "radio" via your camera my Sony calls it "wirele$$", Note the $$. OR a time delay unit looking much like the one above... Seagull SYK-5 Wireless Remote Flash Slave Trigger with Red Eye Reduction ... or a flash like my Zeikos now sold under a different name...
http://www.neewer.com/slave-flash-for-sony-canon-nikon-pentax-olympus-cameras.html
the unit costs $10 and has a rating of perhaps g=40 atISO 100, of course g in feet.

While the power is low, so is the price. I bought 4 which allows me to distribute the light and the g values are additive. With a few simple calculations or some experimental tries you can set up a standard for your units for particular situations.

Note that in the photo, there is a swithch to tell the unit to ignore pre flashes and to sync with the "real" camera flash that is reflected from the subject and recorded on the camera sensor. While I realize that sophistication is nice, like TTL flash and specialized systems for Canon, Nikon, Sony etc... There are times when $$ and KISS (keep it simple shooter) prevail by necessity and ease of use and perhaps even versatility.

NEEWER FLASH WITH DELAY SWITCH