Flash use for macro - Canon

JeffreySipress · #1 07-04-2003, 09:03 PM

I've got a 550 EX, but have rarely used it with my 1Ds. I have been shooting outdoor closeups, some macro, and have used existing light. I need to add the strobe to my setup. A typical example:

While shooting a group of moving ladybugs with a 100mm macro in low natural light, I needed to stop down to f18 or more for DOF, but that put the shutter at 1/3 to 1/2 second, which blurred the bug motion terribly (tripod was being used). The solution seemed to be to use flash (like THicks and all those guys) so I can get the shutter back up to 1/250 or so to stop the action. Well, I'm not at that great location anymore, but I put the flash on and tried a few similar things in the backyard today. I use Av mode and set it at f18. I found a low light subject and shot it without flash at about 1/2 sec. I turned the flash on and made the same shot. The flash fired, but the shutterspeed remained the same. Why? I got NO advantage. Shouldn't the camera have automaticaly compensated for the additional light and shortened the shutter speed? Perhaps I don't yet understand the relationship between flash and camera. I read that this flash will high speed sync to the camera down to 1/250 sec. I sure can use an explanation...Thanks...

Daniel_Frois · #2 07-04-2003, 10:29 PM

Hi,

Well, I don`t know about the 1Ds (unfortunately...), but, on my DCS3c (EOS1n based), with 430EZ, I have to go to manual mode to get the shutter speed to 1/250. In Program mode, the camera will use settings for fill-in flash, balancing available light with flash, which is why the shutter speeds remains at 1/2 or 1/3.

My suggestion is that you use manual mode, and put the shutter at 1/250 and aperture at 16 or whatever you want. With the flash in TTL mode, you should get near-perfect exposures every time, even if you may want to flash-bracket when there are big black or white areas in the frame.

It works for me...

DFrois

JeffreySipress · #3 07-07-2003, 08:48 PM

Thanks, D.

I played around with it all weekend and discovered what you are saying to be true. Other kind RG forum people emailed me, too. With a tripod and static subjects, it's OK to use a longer shutter speed, although the only important point within that time is the moment of flash. So, in manual mode, any shutter speed from 1/250 to 1/5 will work. The difference will be how much ambient light will affect the image, and the blur factor, if handheld or a moving subject. Knowing all this will dictate how I approach each shot. I'm having fun now...