Camera Labs

I've had my Nikon D90 for nearly two years now, and I wanted to try and experiment with flash a little more.

Reading up on the Nikon TTL system I just can't understand how the on camera flash which needs to trigger the off camera flash would interact with the photo.

I've watched videos of people demonstrating the system, but not discussing the effect of this extra light source. I'm guessing that the off camera flash somehow makes the on camera flash redundant?

If you had triggers (like Pocket Wizards) , it wouldn't be a concern - but what are considerations with the TTL system?

Chris

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Nikon D90 18-105mm
Nikon 50mm 1.8D
My Photos

I am not quite sure how you intend to run this. You can have the on camera flash set so it fires or so it doesn't. You will have to use Nikon flash guns for this to work.

Both the Nikon infra red system and the Pocketwizard are expensive, and just for the sake of TTL, you have to ask yourself whether it is really worth it or not.

I have one Canon flash (430ex Mk2) and two Yongnuo's, which are far cheaper. I haven't used them much yet. I trigger them with a fairly inexpensive basic wireless kit. This will not transmit TTL, it only syncronises.

For advanced (eg studio) setups, you will usually want full manual control anyway, especially for running multiple flash units.

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Canon EOS 500D
Lenses: EFS 18-55mm IS, EF 50mm F/1.8 II

Thanks

That is what I didn't understand - I thought the on camera flash had to fire to trigger the off camera flash. That's how the system works. If it doesn't then it answers my question.

Chris

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Nikon D90 18-105mm
Nikon 50mm 1.8D
My Photos

chrissyb

The on camera flash does fire to control the off camera flash using the Creative Lighting System set up.

It's firing to tell the off camera flash to fire and meter the scene using TTL. This all happens before the actual exposure so does not affect the lighting of the image you take. Due to the speed, you cannot tell that it happens before the exposure.

It's up to you, using the camera menus, whether the on camera flash is used in the exposure or not. If you want it, it will fire again during the actual exposure to apply some fill light.

And where wireless triggers come in is when you need to hide the off camera flash and there is no reliable line of sight for this pre exposure communication, or when you're outside in bright sunlight. In bright sunlight the on camera flash can struggle with sufficient output to communicate with the off camera flash.

That's where your triggers come in. Cheap models are available and quoted working distances can vary greatly from actual. It all depends on how much you're willing to spend and how much usage you'll get out of them.

I only use my pocketwizards rarely, but in situations where I want things to work reliably and unobtrusively. TTL is a real bonus if you're shooting an event and can't easily control your off camera lighting position, or the subject distance to the flash changes continually. TTL really helps out then and comes up with the goods.

If you are a Canon or Nikon user and own the Pocketwizard Mini and Flex, you can of course get the Zone controller, which is an add on device that Mark Wallace has demonstrated before.

Depending on the Speedlite setup that you have, sometimes the settings can be controlled from the Master flash or from the camera.

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Canon EOS 500D
Lenses: EFS 18-55mm IS, EF 50mm F/1.8 II