Hoping someone can help. I am attempting to use some studio flash lights in my setup.
I have a Canon EOS 1DS MKII, with a Speedlight 420EX attached to the hotshoe. When firing with just the 420EX, the photo exposes correctly. When I then turn on the 2 x Studio lights (Prolinca 250), the 420EX fires, the 2 x studio lights fire, but the image is underexposed (as if all the flashes had NOT fired).
I haven't changed any settings between firing the 420EX only (and correct exposure), to taking the 2nd, underepxosed image, with the Studio lights on.
I don't understand why the 2nd image wouldn't be correctly exposed as the Speedlight fires normally (this is what triggers the 2 x Studio lights), even if the studio lights were having no effect!
I have tried this with various shutter speeds, from 1/30 to 1/200. This has made no difference.
I have set the 420EX to slave mode and slave mode off. Again, no difference.
I have cleared all custom and personal functions on the camera.
Any help appreciated.