blackest wrote:
Hi i've been asked to produce some portraits and i'm thinking about the lighting ratios needed. If i light from the right what sort of level should i be looking for the shadow side would it be enough to use a reflector to bounce back or do i need a second lower powered light?
I do have a flash meter to help work some of this out.
I look forward to any tips you have.
thank you
I usually set at least a 2:1 ratio between the main light and the fill light. It's possible to do it with a reflector, but a lot easier to set up with multiple lights.
These were shot with two monolights bounced out of a big umbrella on one side (Main) and one light out of a second umbrella on the opposite side (fill). All three lights were set to 50% power, primarily to speed up recycling.
As you can see, 2:1 light ratio makes for relatively flat and uniform lighting with minimal shadows.... especially when it's bounced out of an umbrella in this way. (Try to ignore the problems with shiny, reflective paint on the backdrop! Had to retouch that in post processing... these are just small proofs with minimal adjustment and retouching in Lightroom. Finished images got more work.)
This is what happens when the fill light doesn't fire, so the only source of light is the main light...
The reason that light failed was because I was using a PC cable to trip the main light and having to use an optical trigger for the fill. Someone else set off a flash nearby and caused the fill light to fire early... an instant before I took the shot. Probably someone taking a snapshot over my shoulder... there was a lot of that spoiling my lighting setup at this particular event... radio triggers would have solved the problem!
But sometimes for dramatic effect, a single light source can work (in this case, a very large softbox off to one side with a low powered light and with virtually no light being bounced from the right)...
If I had to guess, I'd say the above is a 16:1 or 24:1 light ratio!
In between these extremes are other ratios... 4:1, 6:1.
When closer I tend to use higher ratios... I rarely use my macro flash at less than 8:1.
Keep in mind that you can greatly vary ratios both by the power settings of the lighting and by the distances from the lights to the subject.
I'd recommend you experiment in advance with your particular light(s), modifiers and reflectors. Once you have what you want, make careful notes of the distances, settings and all... draw a diagram like those above... and it will be pretty easy to replicate when you go to the actual shoot, so you can get down to business quickly and be confident in your setup.