Friday, February 17, 2012

Exposing for Your Vision

Greetings, volks. Welcome to Hohenfels Volks, THE place for our place! Welcome to another delayed post.

Lots of things going on have delayed posting for several days. So today, we’re going to get back to basics a little. We’re going to look at several concepts of exposure and how to use our settings to get our photo as close as possible to our vision in camera. Our next post will deal with bringing that image into our application and bringing to what we envisioned.

First, as you know, exposure is a combination of things, ISO, shutter speed, aperture, and light. You can read more about it here, in our intro to photography. Changing any one of these things will change your exposure. Usually when we’re shooting travel, landscape, and other photos, light cannot be changed for various reasons, so we’ll stick with the basics of the exposure triangle, and metering for our intent and vision.

The first thing to decide is what shooting mode we’ll use. If you’re shooting AV, set your f/stop accordingly. Then we need to know what we’re metering from. Knowing that what we meter gives us a flat neutral 18% gray reading, we know that we’ll be shooting that as our mid tone. Using spot metering in your camera gives you about 7 degrees of coverage, which allows us to meter several areas of our scene. Once we’ve decided what our subject will be and what level we want it placed at, we meter from that. Should we want our subject to be 2 stops under middle gray, we take our meter reading and set our camera 2 stops below that. For instance, your meter tells you that at ISO 200, f/8, your shutter speed should be 1/50, then set your shutter speed to 1/200. That’s 2 stops down from your meter. Remember, that lower values are accordingly decreased, as are brighter values. It’s often useful to take a shot at 1 stop and 1 at 2 stops, or even going by third stops, to get your image values where you want them. It may not look perfect, but when it’s as close as you can get it, it’s time to work your settings through various combinations, adjusting your aperture for DOF effects and your shutter for exposure and creative effects.

It’s often useful to take your readings from several points, your deepest shadow value where detail is to be retained, and your brightest highlight where detail and textures need retention. Going back to f/8 at ISO 200, we find that the lowest value with texture and detail is 3 stops down from middle gray and that may be too dark for your vision. We can make up for some of that in our software, but shadows pushed into higher exposures, introduce noise. That’s why we meter for our vision and not for an average. If we know the darkest part we need to keep detail in, we can build up from there. The same is true of highlights, only building down from there.

Give it a try, shoot RAW, and save your files. When you open them, unedited in your conversion program, that will be called N, or Normal development. We’ll refer to that in our next post.

Hohenfels Volks: Country village at N development
ISO 400, f/16, 1/500, 115mm
A country village along the way, near Hohenfels. This is processed for normal, or N, development in RAW conversion.It's not bad, but can use some help!

Take your favorite shot, metered for your intent. It can be a test shot, in color or monochrome. The point here is learning to use your vision, the light, and your camera to make something you like. After you feel comfortable with metering that way and get some shots that you like, try it on your next shoot. Then we can learn how to get that look you visualized and worked so hard to come up with. It may not be an exact replica of the scene, but it should be what you wanted to see and show us all!

Don’t forget to post any of your images you’d like to see here at the Hohenfels Volks Facebook page. Of course, commenting on both Facebook and here is always appreciated, too! Don't forget, we're on Google+, too!

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