TTL on a canon.....how does it work...

[Robbo]

.... How does the ttl work on the 430 speedlight when the head is swiveled pointing upwards?

As the sensor is at the front? Or is there a sensor inside the light bit?

Have I missunderstood how it works?

Reason asking is my macro set up has the light run along side the camera in it's 'straight' position. So being in that position how will it sense the light is still only poining 20cm from the subject and not up at the ceiling

 

[wontolla]

.... How does the ttl work on the 430 speedlight when the head is swiveled pointing upwards?

As the sensor is at the front? Or is there a sensor inside the light bit?

Have I missunderstood how it works?

Have a look at this it will answer most of your questions hopefuly!

 

[CT]

TTl flash metering is a function of the camera. The flash bounces off your subject - comes back through the camera lens (TTL), and is metered by a flash sensor inside the camera. So it doesn't really matter whether you use flash directly or bounce it.

 

[Robbo]

Ah ok, I was worried that my speedlite sensor is facing the camera and might throw off any readings? That not the case?

So the speedlite still sends a pre flash etc same as the built in one before taking the pic?

 

[Jayst84]

Yep, as CT says, the metering is done in camera. (TTL = Through The Lens) The sensor on the flash is for IR triggering of the flash.

Some older flashes had thyristors, that's when it mattered if the flash body could 'see' the flash on the subject.

EDIT: Yep, sends a pre-flash for ttl metering.

 

[Robbo]

Thank you new gun for me tomorrow then lol