So, last week I gave a quick rundown on how I approach lighting outdoor portraits using ISO, Shutter speed, and Aperture to balance ambient light with flash exposure. I figured talk is cheap so I decided to create a quick (and I’m talking down and dirty!) video to put it in action where you can – hopefully – follow along. Yes, yes, I know it’s a grill and not a person posing or somebody doing a sweet Foot Plant. But, light is light! I actually chose NOT to shoot a person so we don’t concentrate on lighting position and catch-lights and all of those other fun details. I just wanted to look at balancing ambient with flash. So, here it is:
Let’s run through this example really quick (since I was talking at the speed of light!) to give you an idea of how these things all play together:
We’re going to shoot a simple portrait outdoors so we have to balance the available light from the sun with the single light I’m going to be triggering on the subject – in this case my trusty not-so-rusty grill. I know that I want to make the shot dramatic, so I want to drop the exposure of the background 1-2 stops and make it darker (I’m going to drop it 1 stop because that’s the balance I tend to like). So, what are my steps to make this happen?
First, let’s get the background set. In-camera meters on DSLRs make this an easy and awesome process. I’m just going to point my camera at the background, set my ISO to 100 (remember that I want the best quality possible and the least amount of noise), and I’m going to start my shutter at 1/100th of a second. I do this because it is going to give me a little play if I want to drop the background even darker or if I want to make it a little it lighter. I love being able to keep myself as versatile as possible behind the camera so this is my general starting point and – in my eyes – a good overall practice if you’re getting started. Now that I have my ISO and shutter speed set, all I have to do is open or close my aperture until my meter reads 1-stop under exposed. For the lighting conditions in the video, my background exposure is at ISO 100, 1/100th, f/11. Now that my background is set and I have all of my settings in order to make this happen, time to add the light and change the power until I reach a desirable exposure on my subject and have the image I’m looking for.
This part takes some practice (or a light meter). The age-old question of where do I start with my light power? This just takes some practice and learning your lights in order to develop some intuition on where to start. Think about it logically though, if my aperture is really open – I need less light, if it’s really closed like it is here – I need more light. It really varies from light to light and shot to shot. But, I would suggest just starting at half power because you can easily bump the image up or down based on what your in-camera image looks like and where your histogram reads.
There’s our starting point at 1/2 power. From here, I know I need to either raise or drop the the power of the light to get that exposure I’m looking for. As a guide, I’m going to look at the histogram (namely the red channel) and see how I look. It looks like I need to bump up the power of the light about 1 stop. With the Einstein lights, I know that I need to push the up arrow 10 times to reach that desired output.
There’s our exposure with the changed light. Not too bad right (for a goofball shot of my grill in the backyard)? Now I can shoot and compose the shot as much as I want as long as the sun doesn’t change too much and I keep the distance from my light to my subject relatively the same.
Hopefully this quick and dirty look at how ISO, Shutter speed, and Aperture helped shed some light (ha, pun…) on using off-camera lighting and how these different camera settings can be used to affect the exposure of the photograph and balance the affects of a strobe. Next week, we’ll take a look at how we can make this even simpler with a light meter and how positioning a light can make all the difference in how a subject or a photograph appears! So, make sure you subscribe via RSS, Facebook, and Twitter to not miss anything and continue to learn how to light!