Hi everyone. I have been using Canon cameras since the EOS620 came out in 1987ish. I have a 90D which I bought recently. I have acquired a ring flash that works fine in that it flashed when it should. However, I naively assumed that the camera would adjust the exposure/ speed to cope with the flash but when I use the ring flash everything is over exposed. What am I missing here? David
I should mention that I use the set up for photographing scale plastic models. I attach a typical example. The models are in a light box and are typically 6 - 10" long. I use a Manfrotto tripod. This means that the setup is pretty static and consistent from day to day. I take up to 6 images with the focus in various places and use Focus Stacker to put them all together. The lighting in the box is on the roof and the sides. I need something that gives me better exposure to the front, hence the ring flash. Should I be switching to manual and fiddling around to get the exposure right? I thought that TTL exposure would allow for the flash automatically.
Which ring flash do you have? it sounds like you have a TTL flash so it should be doing the exposure for you as you had thought. However you did mention light on roof and sides, are you triggering other flashes they should all be tied into TTL if that is the case, or your ring flash is probably trying to light as if it is the only flash. You would want to dial in exposure com[compensation if you have additional lighting. Maybe there is some exposure compensation dialed in throwing off the exposure. Honestly i you are using multiple lights you should use all TTL or all manual for easiest and most consistent control either works well. I have done some light box photos with multiple 580's on external triggers. You do usually have to fine tune the compensation on each flash if your not setting it manually.
I think you are right. Since posting, I have been playing with ~Manual and that seems to fix the problem. I am now getting OK exposures. Than ks for your response and help. David
