Help my speedlite fires but my shutter speed is too low

[KKCFamilyman]

I have a canon 5d mkiii and I am testing my new 270ex ii for vacation and in tv mode shutter 1/125 iso 400 wb flash eval metering it tries to use 1/3 sec or best I can get is 1/20 at iso 1600. I thought it was my batteries but I recharged them. I put my 430ex ii on and same results. Any suggestions? I should be able to shoot at iso 400 with a speedlite? I even reset all my settings. Very frustrated 2 days from a trip.

 

[briansquibb]

I have a canon 5d mkiii and I am testing my new 270ex ii for vacation and in tv mode shutter 1/125 iso 400 wb flash eval metering it tries to use 1/3 sec or best I can get is 1/20 at iso 1600. I thought it was my batteries but I recharged them. I put my 430ex ii on and same results. Any suggestions? I should be able to shoot at iso 400 with a speedlite? I even reset all my settings. Very frustrated 2 days from a trip.

In TV mode the camera is setting the speeds based on the ambient light rather than using the flash to light things up.

Try using M at 1/125, iso400, f/5.6 for starters and adjust from there. The more flash light you use the darker the background gets