Macro photography with a ring flash

Question

Being relatively new to photography I want to try some macro photography of flowers in my garden. I've bought a set of macro extension tubes and a ring flash (both unbranded and cheap to start with). I'm using a Canon 50D camera, the few test pictures I've taken so far have all been totally burnt out (white).

I assume the issue is that the camera is metering on ambient light, is there a way to calculate the correct exposure settings so that the exposure is correct or do I just have to use trial and error? I have been using the macro setting on the camera, but think I may have to use manual. The flash unit instructions are externally brief and poorly translated from Chinese but include guide number but no units.

Answer 1

First step: Practice macro without the ring and get used to the extension tubes.

Second step: Your camera will not be aware there is a flash fired, so it does not calculate this into the exposure settings. You have a couple of options (and probably more):

• You need to correct the metering manually, either by using the camera in manual mode (M) and do it all yourself
• or by using the exposure correction when in AV (TV would not make sense normally).
• For the case you have a LED macro ring, there might be an option to enable a permanent light. When this is on, the camera will do the metering correct