Page 1 of 1

Nikon CLS questions

PostPosted: Sun Jan 15, 2012 1:53 am
by Trevor Harris
Hello all,

I've got a few technical questions about the Nikon CLS. I've contacted Nikon, but with no response, so I'm posting here to see if anyone can help me out.

So my setup is a D200 with an SB-600 and I rented an SB-700 for this weeknd. I can control them both remotely, different groups and channels, yadda yadda yadda… I'm using my pop up flash as my master to control the both. I realize that the 700 can be master, and thus control the 600, but I'm not getting in to that at this point. My question is, if the signal to power both flashes is an IR-signal. IR is invisible to the naked eye, so why does the popup flash appear to illuminate?

Secondly, from what I understand, there is a pre flash that occurs (presumably after the ir signal is set) for TTL purposes. The second flash on all speedlights is the actual exposure based on metering from the first flash. So if both flashes are set to manual, then would this pre flash occur? When a photo is taken, there seems to be a dizzying array of flashes that occur, albeit it's pretty fast, but it could cause some to have their eyes closed in some photos.

That's all I have for now, but I'm sure I'll have more questions later. Thanking you in advance,

Trevor

PostPosted: Sun Jan 15, 2012 12:38 pm
by Citruspers
CLS is indeed controlled by an IR signal, but the flash bulb actually emits both visible and non-visible (IR) light. You can get an attachment which is basically an IR pass filter that only allows non-visible light to pass through it, but I've found that it doesn't affect my exposures that much.

PostPosted: Fri Feb 24, 2012 6:25 am
by palakaboy
tell them to close their eyes and to open once they hear three.

if you're taking portraits, I'd suggest you take multiple exposures to ensure no-blinkies.

there's no way around this but to purchase an SU-800.

the reason why it flashes is because you're using a flash, If i decided to use a chainsaw to cut a watermelon, it's still going to create the buzzing chainsaws make.