Sunday, 21 February 2010

EOS 7D Off Camera Flash Outdoors

There was a pleasant gap in our wonderful English weather over the weekend so I took the opportunity to test the Canon EOS 7D off camera flash control outdoors.

In bright sunlight the effectiveness of the off camera flash control is reduced to around 8 - 10 feet line of sight. And even then, you only have to move slightly for control to be lost. I've found that outdoors the Canon EOS 7D off camera flash control is best early in the day, overcast/cloud, dusk & dark, as you'll see from the following example.


The kit is very straight forward: two Canon 550 EX Speedlites, three Manfrotto 026 tilt and swivel umbrella adaptors, one Manfrotto 035 Super Clamp, heavy duty lighting stand, medium duty lighting stand, three sand bags, electrical or gaffer tape, Rosco Strobist Gels, silver 36" umbrella and a "willing" model.

Why three 026 umbrella adaptors? Simple - a quick way of mounting two Speedlites to shoot into one brolly without buying a special adaptor*. You simply attach two of the umbrella adaptors base to base with a double ended 5/8th inch/16mm spigot; clamp the Super Clamp where the adaptors join and the attach the third umbrella adaptor to the Super Clamp. This allows you to attach the rig to a lighting stand and hold the brolly in place.


I use mini ball and socket heads with hotshoe adaptors to attach the Speedlites. This allows me to direct the Speedlite sensors toward the camera or Speedlite controller. The light from the Speedlites was warmed up by using the 1/2 CTO daylight to tungsten colour correction gel. The uncorrected flash would have looked too cold or blue for these shots.

This shot shows the set-up for the shot below. I kept two sandbags on the base of the stand with the brolly light as there's a greater chance of this imitating a kite should the wind speed increase. For the first shot, one sandbag on each leg of the lighting stand (approx. 30 kg/60lb total) in view of the instability caused by the top heavy weight.

As part of this exercise, I limited myself to two 550 EX Speedlites. For the second shot I separated one from the brolly unit and attached it to a smaller stand, to camera right and behind the model. This time I replaced the 1/2 CTO gel with a much stronger no. 23 orange gel and a black Rosco Photofoil snoot to avoid any flare into the lens. As the light was now fading rapidly, this helped separate the model from the sky and background.

For this whole exercise the canon EOS 7D was set to Av (Aperture Value) and the exposure compensation either -1 or -2 stops. ISO 400 with a 24 - 105 mm f4 IS L Series lens, white balance daylight. The majority of the shots were shot with the lens at 24 mm (38.4mm on APS -C sensor) or 35 mm (56 mm on APS-C sensor). Both Speedlites were receiving their instructions from the camera's in-built Speedlite controller.

The Speedlite for the shot above was moved to Group B so that I could control the power ratio between the main light to camera left (Group A) and the effect light to camera right (Group B). This shot the ratio between the two lights was 4:1 (A:B).

Conclusions
For anyone wanting to begin experimenting with off camera flash, the EOS 7D is a great unit. Personally, I use either an ST-E2 Speedlite controller or some sort of radio trigger as these options offer more flexibility. Most radio triggers require that you use your flash in manual mode, which is more suited to more experienced photographers. Using the EOS 7D or ST-E2 you can use your camera controls and E-TTL flash which makes creating images (slightly) more simple. Much of the time I use the ST-E2 on an extension lead so that I can aim it more accurately at the Speedlites and maintain E-TTL control.

* This is OK providing you have a vast collection of grip gear!

TTFN

Ian



1 comment:

  1. Ian - great post! Would you mind posting some of these in our Rosco Strobist Flickr Pool?

    http://www.flickr.com/groups/1239258@N21/pool

    Joel Svendsen
    Rosco Laboratories
    joel@rosco.com

    ReplyDelete