Monday, November 23, 2009

7D Hannah

Having previous posted a series on portraits and depth of field based on my G9, I decided to repeat one shot using the 7D. Fortunately, Hannah was still available. The 7D was fitted with a Canon 85mm f1.8 and set in Av mode for f1.8 at ISO 100. The setup and distances were roughly the same as previously posted with the G9.

It was a nice clear day outside and even at ISO 100, the shutter speed was 1/8000 second! Incredible as this seems, it actually is almost exactly the “Sunny Sixteen” exposure albeit shifted quite a bit. The combination of sunlight and concrete made for very harsh lighting and I give full credit to Hannah for not squinting. But, getting back to the point, notice the blurred background. In fact, notice the slight blur of the front tire!

With the setup and a patience model, I just had to try a few shots using the 7D as a trigger for a 580EX flash outdoors. The 7D flash system is very intriguing and I’ll be learning more about it. In fact, I learned something today.

I first attempted to place the 580EX slightly behind Hannah to provide a bit of back lighting and separation from the background. The 580EX simply would not flash. Hand-holding the 7D, I was about 20 feet away. It turns out that you have to remember to turn it on! But even then it would not fire until the 7D was about 4 feet away. I could see the red light blinking on the 580EX but finally realized that the 580EX was seeing a tiny little pop-up flash and a huge bright sun. With the 580EX facing away from the sun, the 7D will easily trigger it from 20 feet away. Lesson learned.

Taking another approach to lighting Hannah, I decided to underexpose the background and use the 580EX to light Hannah from camera right. Accomplishing this was made complicated because the sync speed of the 7D is limited to 1/250 second and at 1/250 second, the ambient exposure was f11. Giving it a try, I switched to manual mode and set 1/250 second and f22 – about two stops underexposed for the background. The 7D flash system was set to an 8:1 ratio for the external flash. The result – first attempt! – is below.

Not too bad for a first try and definitely better than most of my first guesses with fully manual exposure and manual flash.

I like the ability to blur the background and the opportunity to use my 85mm lens with the 7D. As a flash trigger, the 7D seems OK outdoors with a range of 20 to 25 feet provided the auxiliary flash can see the 7D without also seeing the sun.

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