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Mandi Goodsett
LIS590UMI
Project II
3/28/12

    As future information professionals working in cultural repositories, many of us will be handling digital cameras, whether to digitize materials, assist in various library functions, or offer technology for patrons to use. Choosing the best camera for the situation requires looking at the camera features available and allowing them to inform the decision. However, while the features of various digital cameras are well advertised, what these features actually mean is not immediately clear. In looking at the available features for most digital cameras today, I found seven features that are common in cameras but that could use some explanation for the non-camera expert. For each of the features I used my own digital camera to demonstrate how they affect the resulting photos.

Resolution
    One of the most commonly compared features in digital cameras is the megapixel count, or the resolution. The word "pixel" is actually short for "picture element," and each one consists of a small unit of information ("Pixel"). A single pixel can only contain information for one color at a time, and it is the combination of pixels that creates the images we see on televisions and in photos ("Pixel"). While a pixel can only be one color at once, the range of colors one could potentially show depends on the number of bits available to represent it, so it is important that a camera's imaging chip has a high enough bit-rate to capture a wide variety of colors ("Pixel"). It's also important that the camera has the ability to capture many pixels, thereby reducing the graininess of photos (because individual pixels are not as visible). Today most cameras have a resolution of ten megapixels or higher, which is more than necessary if the user means to make images smaller than 11 by 14 inches; in general, five megapixels is enough to make a clear 8 by 10 inch photo (Movnihan).

Zoom
    There are two kinds of zoom: optical and digital. With optical zoom, the camera uses the lens to physically extend closer to the object being photographed, which does nothing to deteriorate the resolution. Digital zoom, however, involves a process of cropping the image and enlarging what remains to make the image look bigger, which results in an image with lower resolution ("Digital Camera Features"). If a camera user is hoping to create high resolution photos of things that are far away and still retain clarity, he or she would be better off finding a camera with good optical zoom. If the user is usually taking pictures of things that are very close (such as when digitizing objects), zoom may not be as much of an issue (although other features then become more important).

Red Eye Reduction
    Red-eye in photos is the result of the light from the flash reflecting off of the retina in someone's eye--the red color comes from the blood vessels in the eye off of which the light is reflecting ("Why do people ..."). Most cameras (and photo editing softwares) today have the ability to reduce or correct red-eye in photos, and this can be done in several ways. One way of reducing red eye is to cause the flash to go off twice. This compels the subject's eyes to contract after the first flash, which eliminates exposure of blood vessels (and, consequently, red eye), and takes a red-eye-free picture with the second flash. Another method of reducing red eye that is more useful for professional or very serious photographers, is to move the flash away from the lens by detaching it and holding it as far as possible from the camera. This prevents light from the flash from reflecting off the lens--which is very close to the flash on most digital cameras--and showing up in photos ("Why do people ..."). Most camera users will want to have either the ability to reduce red eye on the camera itself, or a kind of photo editing software that will allow for red eye to be removed from photos.

Focus/Exposure
    Some cameras provide ready-made settings for focus and exposure depending on the situation--what is being photographed, the time of day, the amount of light in the shot, etc. These settings are created by altering the shutter speed and the lens aperture ("Digital Camera Features"). The aperture is a hole in the lens that can be varied to allow more or less light through, and the shutter is the cover that controls the length of time light is exposed to the camera's sensor (Bargh). Together, these camera features can allow a photographer to both improve photos in various situations and make creative alterations to shots; however, many cameras (especially compact ones) only have automatic settings and do not allow for the photographer to override them and make manual adjustments (Bargh). Camera users interested in using shutter speeds to alter photos will want to take a careful look at whether or not that feature is manual or strictly automatic, and if the latter, what kind of automatic settings are available. Some cameras offer a wide variety of exposure settings, so this might be something to consider when choosing a camera if having that variety is important to you.

ISO
    A high ISO setting (3200 or better) can improve shots with low light, especially those at night, so depending on the function the camera will serve the ISO feature could be somewhat important in the decision of which camera would be best ("Digital Camera Features"). ISO (a slightly altered acronym for International Organization for Standardization) settings determine how sensitive the image sensor of a camera is to the light present, and it is often altered in combination with shutter speed and aperture to improve the exposure of a photo ("What is ... ISO"). The ISO setting can be useful in situations when there is not enough light in the scene and flash cannot be used to increase the amount of light (at a concert, for example); in a case like that, the ISO setting could be raised and the camera sensor would capture more light, even the more faint rays ("What is ... ISO"). Unfortunately, while this can improve the exposure of a photo, it also adds noise, so the best image quality comes from taking photos with the lowest ISO setting possible ("What is ... ISO"). While it's often best to leave the ISO setting alone, for photographers taking photos in dark situations often, or those interested in having a lot of control over the exposure of photos taken, examining the size of the image sensor in a camera would help determine if it will allow for sufficient ISO setting options.

Metering Modes

    Most cameras will have an automatic setting for metering, but this feature can be manually changed. The metering mode determines how to expose a shot correctly based on the amount of light available ("Digital Camera Features"). Evaluative metering is usually the default setting, and it automatically adjusts the metering based on the subject of the shot, whereas in spot metering the camera chooses a spot within the center of the shot from which to base the exposure, which can be useful for shots that are backlit (Charon). Center-weighted or average metering combines both of the previous settings: it bases the exposure on whatever is in the center of the shot, but it also takes into account what is happening in the background (Charon). Being able to manually alter metering modes can improve any kind of shot taken in a darker settings or that has elements with drastic differences in lighting.

White Balance

    This feature helps camera users eliminate unnatural lighting from light sources in a shot. This can be especially important when a light source in a shot does not match the overall color characteristics in the rest of the shot--whether there is an incandescent, red, or yellowish cast in the photographed space. The unnatural colors that we capture in photos, but which aren't detectable when we see things with our eyes, is caused by the color (or temperature) of the lighting that is illuminating them (Rowse). Most camera users just leave the white balance at its automatic setting, but digital cameras that allow for manual adjusting give users the ability to get creative with lighting in photos or fix photos that have jarring light contrasts ("Digital Camera Features"). It can help if the camera you have has settings that guide the white balance you want in your photo. Some settings often found on digital cameras include tungsten (best for under incandescent lighting), fluorescent, daylight/sunny, cloudy, shade, and, of course, automatic (Rowse). Examining which white balance features are available in a camera can help librarians decide if it is going to provide them enough options for the functions they'll want to the camera to serve.

    While many of the features outlined above are often left at their automatic settings by the average camera user, knowing whether the camera you are considering buying or using has these features and how to use them can improve a your purchase decision. For librarians, having a basic knowledge of what these different features do can also help them better serve patrons through visual displays, technology available for use, and the digitization of materials in the collection.

Sources
Bargh, Peter. "Introduction To Camera Shutter Speeds." Digital Camera Reviews, Photography Techniques, Photography Gallery and Photography Forums. EPhotozine, 5 Dec. 2011. Web. 21 Mar. 2012. http://www.ephotozine.com/article/introduction-to-camera-shutter-speeds-4794

Charon, Laura. "Metering Modes Explained." Digital Photography Tips. Digital Photography School, 2010. Web. 21 Mar. 2012. http://www.digital-photography-school.com/metering-modes-explained

"Digital Camera Features." Digital Camera Features. Squidoo, 2012. Web. 23 Mar. 2012. http://www.squidoo.com/digital-camera-features

Moynihan, Tim. "How to Buy a Digital Camera." PCWorld. PCWorld, 24 Oct. 2011. Web. 23 Mar. 2012. http://www.pcworld.com/article/125645-3/how_to_buy_a_digital_camera.html

"Pixel." TechTerms. TechTerms, 2012. Web. 21 Mar. 2012. http://www.techterms.com/definition/pixel

Reichmann, Michael. "Understanding Resolution." Understanding Resolution. Luminous Landscape, 2012. Web. 21 Mar. 2012. http://www.luminous-landscape.com/tutorials/understanding-series/und_resolution.html

Rowse, Darren. "Introduction to White Balance." Photography Tips and Tutorials. Digital Photography School, 2010. Web. 21 Mar. 2012. http://www.digital-photography-school.com/introduction-to-white-balance

"What Is... ISO." Digital Photography Tutorial. Photoxels, 2010. Web. 21 Mar. 2012. http://www.photoxels.com/tutorial_iso.html
"Why Do People Have Red Eyes in Flash Photographs?" HowStuffWorks. HowStuffWorks, 2012. Web. 21 Mar. 2012. http://www.howstuffworks.com/question51.htm