if I photograph a portret (2 x lamp) against a white background and I also put a lamp (1 x lamp) on the background then I get a blue spot on the portrait.... can you help me to solve this.
Much thanks.

Thijs

lens flare ?

An example

Lens flare. Make sure you're using a lens hood that blocks any direct light path between your flashes and the front of your lens.

Much thanks.

I will buy a new larger lens cap and a put down a couple off flag's..

Regards

Thijs