Analyze Metadata to Improve Your Photography Shots

In the days of film cameras, I seldom recorded exposure settings that would have helped me better analyze my pictures. Now, digital cameras handle all that work for me, and I can use that information to figure out what went right or what went wrong.

 

Every time you click the shutter, your digital camera records valuable picture data that describes the image you just captured. Data such as time, shutter speed, aperture, focal length, and ISO are written to the file header in the Exchangeable Image File (EXIF) format. This information becomes part of the total image file and can be displayed with applications such as Photoshop.

 

In essence, each picture file contains a complete photographic history of the decisive moment, which can be analyzed to help you understand why the image was successful or give you clues as to what went wrong. In this hack, I'll show you how to retrieve this data and use it to perfect your photography portfolio skills.

 

What Is EXIF?

The EXIF format is an international specification, first established in 1995, that enables digital cameras (and other imaging devices) to write data to the file header of the image. EXIF files use the JPEG DCT format specified in ISO/IEC 10918-1. The picture portion of the file can be read by any application supporting JPEG, including web browsers and image editors. The metadata can be accessed by applications designed to extract that information out of the header and display it. The most common imaging applications have no problem displaying at least some of the EXIF data.

 

However, the picture file usually contains more information than what's typically displayed by a given application, unless that application is designed specifically to output EXIF information. For example, iPhoto on the Mac provides the basic time, date, file size, and camera information when you click on the Photo tab of the Show Info window. If you click on the Exposure tab, you get more data, such as shutter speed, aperture, focal length, exposure compensation, metering pattern, and flash status.

 

But iPhoto doesn't provide you with other data sitting there in the file header, such as whit balance. If you need that information, you have to open the file with another application designed to grab that data. The point is that the EXIF specification dictates what goes in to the picture file, but image editors typically give you only a portion of that information. So, if you get serious about reading this stuff, you might need to add a couple tools to your imaging bag of tricks.

 

Why Would I Want to Read EXIF Data?

When you take pictures, some turn out better than others. Why is that? Beyond good composition and subject matter, there are many factors that contribute to powerful images. These include time of day, depth of field, proper shutter speed, and exposure compensation as needed.

 

If you look at a picture of running water, for example, and you like the way it's rendered, wouldn't it be nice to know the settings that you used, so you could duplicate the effect? Before digital cameras were available, I would take handwritten notes to help me remember the settings for particular shots. I hated that! Now, the camera records all that information for me, and I'm free to concentrate on taking good pictures.

 

I know that I can control the way water appears by adjusting the shutter speed. The 1/250-of-a-second exposure "stopped the action" to some degree and the 1-second exposure created a soft look. Now, the next time I shoot running water, I can capture the exact effect I want by adjusting the shutter speed.

 

Source: O’Reiley | Website for Photographers |   Portfolio website for students

Learn Photography: Create the Maximum Depth of Field

Imagine the kind of pictures you could take if everything were in focus from one foot to infinity? Here's the inside scoop on one of the oldest secrets in photography.

Galen Rowell, one of my favorite photographers, used to create landscape compositions in which both foreground objects and distant elements appeared in perfect focus. The effect is stunning. The viewer can both study a delicate pattern of petals in a foreground flower and marvel at the beauty of outlying mountains. How did he do that?

Galen found a way to capture tremendous depth of field in his images. In other words, he could have everything in focus, from inches away to infinity. You can employ this same technique in your photography; you just have to know the hack. Three important factors come into play on these types of shots:

The focal length of your lens: The wider the better

The lens aperture: The smaller the better (f-16, f-22, etc.)

The object on which you focus in the composition: Contrary to expectation, it's not the thing closest to you.

Once you've properly set these adjustments, you can create depth of field that spans from a foot in front of you to the puffy clouds drifting by.

 

2.12.1 Focal Length: The Wider the Better

Wide-angle lenses, or zoom lenses set to wide angle, are a key factor in depth-of-field photography. They help create the illusion that more things are in focus. Galen Rowell usually shot with 35mm film cameras, and often he would use a 24mm wide-angle lens for this type of landscape image. For this hack, I recommend you find a digital lens that provides a film-camera equivalent of a 28mm lens. You can go wider if you want (such as 24mm), but as you'll see, that's easier said than done in the digital world.

For example, if you're shooting with an SLR, such as a Nikon D70, then you would need to use Nikon's 17-55mm zoom lens to get roughly the same angle of view as Galen's 24mm lens on his 35mm SLR.

Why? Well, the D70 and many other digital SLRs have image sensors that are smaller than 35mm film. That changes the relationship between lens and camera, and the result is that you often have to multiply the focal length of the lens by a factor of 1.5 to get the same angle of coverage that you would with the lens mounted on a film camera.

If you multiply the Nikon 17-55mm zoom lens by 1.5, you get the 35mm equivalent of a

25.5-82.5mm lens. You may or may not care about all of this. But what you do need to know is that you have to find a lens with a film-camera equivalent of at least a 28mm lens for this type of photography. The Nikon 17-55mm zoom on a D70 should work nicely.

If you're shooting with a digital point and shoot, such as a Canon PowerShot A80, then your built-in zoom lens (7.8-23.4mm) has the film-camera equivalent of a 38-114mm zoom lens? not quite as wide as we'd like for this type of shooting. The good news is that Canon offers a wide converter (WC-DC52) for this camera that attaches over the built-in zoom lens. It extends your field of view to a healthy film-camera equivalent 24mm lens. Cool! In fact, many digital point and shoots accept wide-angle lens attachments. If you're interested in this type of shooting, then you'll want to make sure your next camera has this.

Source: O’Reiley | Portfolio Websites for Photographers