Champing, cute I had never heard that before I had to look it up. You've probably by now realized that you take on the ISO is reversed. I don't doubt it was happening we just need to figure out why. Were you shooting in manual mode? How are you triggering the flash? I'm not familiar with the 5100 but I didn't think it has a plug for external flash. You have to be careful if you're using a slave. The camera's preflash will trigger your strobes prematurely. if you were shooting in some kind of auto mode, Lowering your ISO may have extended your shutter speed, and those overexposed photos were the only ones actually taking full advantage of the strobe's output. If your strobes have modeling lights the higher ISO photos may have been made using either those or the overhead lights in the room.

Tonight I set up two umbrella lights for group of 7 and individual portraits. I have a large reflector that I am using to help separate subjects from the backdrop. Did some test shots and I have to go up to 800 ISO and that is scaring me to death. I believe it is called chimping (please correct me if I am wrong) anyway the pictures looked ok on the camera. Any lower ISO it was way to light. I am using a D5100, and did not bring it home with me ugh. Hindsight should have and downloaded those pictures. I may have to go back in very early in the morning and check them out on the computers at work. Please tell me someone that it will be ok and I won't find alot of noise on those pictures. As you can tell it is my first time working with that kind of lighting. Usually I welcome firsts in my life, but this one is troublesome. I have so much to learn and sometimes it is kind of painful. Any suggestions here I will be forever grateful. I will let you all know if I passed or failed tomorrow, but for now would like to hear your thoughts. I know I have read that there are some out there with a D5100 so please share.

Tonight I set up two umbrella lights for group of 7 and individual portraits. I have a large reflector that I am using to help separate subjects from the backdrop. Did some test shots and I have to go up to 800 ISO and that is scaring me to death. I believe it is called chimping (please correct me if I am wrong) anyway the pictures looked ok on the camera. Any lower ISO it was way to light. I am using a D5100, and did not bring it home with me ugh. Hindsight should have and downloaded those pictures. I may have to go back in very early in the morning and check them out on the computers at work. Please tell me someone that it will be ok and I won't find alot of noise on those pictures. As you can tell it is my first time working with that kind of lighting. Usually I welcome firsts in my life, but this one is troublesome. I have so much to learn and sometimes it is kind of painful. Any suggestions here I will be forever grateful. I will let you all know if I passed or failed tomorrow, but for now would like to hear your thoughts. I know I have read that there are some out there with a D5100 so please share.