What is metadata and how to use it?

Metadata is a set of information stored when an image is captured by a digital camera. The word itself simply means 'data about data'. Every file format like the JPEG, RAW or TIFF has it own set of data stored either onto itself or in a separate file. Since metadata consists of all the data, such as filename, copy name, file path, rating, text label, and all EXIF and IPTC metadata. There are various standards defined for metadata such as EXIF, IPTC or XMP. The most famous among the professional photographers is the XMP made by Adobe.

EXIF stands for Exchangeable Image File Format; stored into the image; used for JPEG, TIFF and RIFF; stores date, time, camera model, exposure, focal settings, brightness value, exposure bias, suject distance, ISO speed rating, flash firing, metering mode and image dimensions.

IPTC stands for International Press Telecommunications Council and was originally a standard for news exchange between all the news agencies in the world. The IPTC image metadata standard is defined for information interchange and is based on XML.

XMP stands for Extensible Metadata Platform and combines, processes and stores all the metadata available from the camera. It is, in simple terms, a combination of all the metadata formats. It was created by Adobe is now employed in Lightroom.

Professional photographers require all the information captured by the image sensor in the digital camera, to sort out the photographs and for advanced editing and thus they used the RAW file format. It stores the whole set of information that defines the metadata of the image into a file called the sidecar files. While capturing images in JPEG or TIFF format the camera's compressing algorithm writes the metadata onto the files rather than into some sidecar file. Most of the cameras now use a standard metadata definition like XMP. Windows Vista displays the metadata in its Image Viewer.

Metadata is very important for photographers as it helps them keep a track of their image collection.

Adobe Lightroom

Few articles ago we came across RAW formats and its importance for perfect photographs. But which software do we use for editing RAW format photographs? There is a wide range of softwares to choose from the market, for RAW photo processing. Lightroom is one of the softwares which help a photographer, whether professional or amateur, in editing his photographs. It’s a very simple tool to use for amateur photographers.

According to Adobe, “Adobe Lightroom is a new, exciting image handler built from the ground up for professional photographers.” It supports a wide range of proprietary image formats like JPEG, TIFF, PNG and open formats like DNG and XMP. Lightroom is certainly not for photographers who would like detailed pixel editing like Photoshop. But this software offers the best processing options from capture to print and presentation.

The window is neatly organized with all the options. Lightroom window gives us: module picker, panels and filmstrip

Module Picker - It consist of Library, Develop, Slideshow, Print and Web. The name suggests each of the functions and the module picker options are arranged in the order of processing.

Panels - Panels consist of tools used during the process module like histogram, advanced photograph settings, navigator, presets and a history of actions. The panels are distributed to left and right of the window. Most of the processing tools are towards the right and it doesn't take much time once you know what each tool does. Each setting uses a slider or the settings can be edited directly in the histogram and the tone curve.

Filmstrip - Like analog photography filmstrips, digital filmstrip is shown to the bottom of the window. It shows all photographs from the selected folder or the complete library. A photograph can be selected for editing.

Lightroom entertains the Undo (Ctrl + Z) and Redo (Ctrl + Y) key strokes. For the list of commands press Ctrl + /. It also has preset key commands for most important features like hide/show panels or show before/after photos. The best part about Lightroom is a feature called Dim light (L). It dims the light only to show the photo and nothing else on the display just like in a film negative processing room. The software also has impressive metadata editing options. All the photographs, with any format, are tagged with all the metadata information imported from the sensor of the camera. Finally after editing the RAW photos and exporting them, the software adds a customized watermark for a copyright.

Adobe Lightroom is the best software one can use for processing of raw formats and professional digital photography. My favorite Lightroom features are: Easy key commands for faster processing, Size Ratios for precise editing, Before/After (Y) photos side by side for comparison, Full screen, Histogram and Tone curve.

Motion Blur

Photographers despise any kind of errors in the pictures they click and process. Photos with errors immediately find their place in the recycle bin. But did you know that some photographers purposely create errors for magnificent effects? One of these errors is called as the Motion blur effect. Of course, this procedure occurs due to manual setting errors or camera usage errors but one has to know how to eliminate it in order to reproduce it.

A motion blur occurs as a continuous streaking of a moving object when captured as still images. Various causes lead to production of motion blur: Shutter, Aperture and Camera motion.

How does a shutter work and what is shutter in a lay man's language?
A camera shutter is very similar to the eye lid of a human. The shutter operates like the battling of your eyes. Now try this. Keep staring at an object and close your eyes. After a constant period of time of staring, no matter how much you try to shake it off you can see the outline of the object. This is exactly how your camera shutter works. Every click of the picture closes and opens the shutter and thus allows the digital sensor of the camera to capture light. A camera shutter has its own timing to capture the light which is then stored as data into the camera's digital sensor. A blur is caused when the camera shutter is open for a longer time and it captures the image without refreshing or erasing the changes in light. Hence, for the purposeful blur effect the camera should be tuned such that the shutter is open for a longer time! This is done using the Shutter Mode of the digital camera.

What is a camera aperture and how does the aperture work?
A camera aperture is simply the hole through which light enters the camera. This is very much analogous to the pupil of your eye. When you look at yourself in the mirror, notice how your pupils open wide. This is what happens in the Program Mode of your camera. The aperture automatically changes size to allow suitable light into the camera. Photographers often try to adjust the shutter speed to compensate light for the motion blur effect, but sometimes you really don't get the perfect shot. This is when you try by adjusting the aperture. Motion blur is practiced mostly on illuminated objects and sometimes when there is too much of light, the effect is not captured properly. Aperture can use as a fine tune knob for the perfect exposure.

How does camera motion affect motion blur photography?
Motion blur effects are also created using camera motion. This is done when the object is still.

This image on the left is the motion blur created by simply moving the camera to make a 'P'. Remember, everything the camera sees is inverted. The object, candle was in single position while the camera moved creating this alphabet through the wonderful effect.

The image on the right is not very different from the one on the left. The camera was being shook more violently in a random manner so create these sine waves. In both cases the subject was a candle in still position.

Almost all cameras now have the option in Aperture mode which can be used to change the aperture or the size of the opening through which light passes onto the sensor. There is no default or fixed aperture and shutter setting for the motion blur effect. Every lighting condition has a different combination setting. Try venturing by changing and clicking at random.

RAW and JPEG

A perfect setting in a camera is how you get the perfect picture. Almost all DSLRs have a recording mode called RAW.

A RAW file format is the digital negative of a digital photo. It contains unprocessed information that is stored in the digital camera's sensor when the picture is clicked. It stores the file header that contains white-balance information, changes made to contrast, saturation, and color with the Digital Effects Control, any image processing applied in a subject program setting, and changes to sharpness. Hence the name RAW. Different companies use different file extensions: Minolta(.mrw), Canon (.crw), Nikon (.nef), Olympus (.orf), Sony (.arw) and Casio (.bay).

Most DSLRs in the modern times employ better post-processing algorithms to convert RAW to JPEG with lesser losses. So JPEG can be preferred for photographs which are not for exhibit purposes. The writing time is faster, bracketing mode can be employed and memory occupied is lesser. These formats involve no post-processing as it is already done by the camera according to the setting and then stored onto the storage drive.

RAW formats are used for advanced photography and can be edited to any setting like sepia or black & white. Photo editing softwares like Adobe Photoshop with a raw-file plugin is used to get the perfect print for exhibit purposes. In few cameras like the Minolta DiMAGE 7i, delays of thirty seconds can occur as the image is save onto the CompactFlash Card or the Microdrive. It is preferable to use such formats only for still photography. RAW format mode also disables the usage of continous or UHS advance bracketing modes. But in any case, RAW formats are only used for still photographs which have to be post processed using a software.

Professional photographers usually spend a lot of time processing the RAW files using softwares like Adobe Lightroom or Apple Aperture. Amateur photographers can prefer the JPEG format for faster clicks while professional photographers should use the RAW format.

Point and Shoot

Hitech city ©kvprashant and pixelbugs

One of my first photos, I realised the best way to click it is just point and shoot. I found ambient lighting and a perfect structure! I obviously did not have to use any manual settings.

The secret to any photo lies in capturing a perfect subject from a perfect angle in the perfect light. And voila! Most of the times, its the subject that makes perfect photographs. All it takes is a little bit of imagination and photographers can do away with manual settings. But manual settings will help improve the subject and most often photographers use it for better exposure or any kind of effects.

If you are a newbie try to depend on surrounding lighting for perfect click rather than tweaking your camera. Once you are familiar with the camera after refering to the instructional manual you are ready to click away using manual settings!

This photo called, The Cyber Towers - Architectural advent was selected for the Linz Texas architectural centre exhibition's catalogue called LINZ TEXAS A City Relates in Vienna, Austria. The topic was software and technology parks.

Photo details:
Camera maker: Vivitar Syntax-Brillian
Camera model : Vivicam 3746
F-stop : Unknown
Exposure time : Unknown
ISO speed : 100
Exposure bias : Unknown
Focal length: Unknown
Max Aperture : Unknown
Metering mode : Unknown
Color presentation : sRGB
Resolution unit : Unknown
Bit depth : 24
Dimensions : 1583 x 1501 pixels
White Balance : Sunlight
Brightness : Auto
Saturation : Normal
Sharpness : Normal
Contrast : Normal
Horizontal resolution: 300 dpi
Vertical resolution : 300 dpi