i hesitate to buy this white balance gray card for a year now and i wish i could take those time back. i used flash 98% of the time and setting up the white balance according to your flash temperature is a must if you wanna save time on editing and get the result right away when you take photos. this gray card is very useful especially when theirs tons of lights mixing together in your subject because our camera always getting the wrong white balance when it comes to that scenario. highly recommended for beginners and professionals.