Sunday, May 11, 2014

Determining Lines, Inches, and Pixels

If we are aware of the size, density, and number of pixels on a sensor and recognize the other variables to a camera's resolution, are we better able to determine the quality of the images a camera can produce? The answer is a resounding no. Pixels are the units of measurement relating to the camera's resolution only, not the image resolution.

Raw camera resolution is shown in pixels, but image resolution is referred to in ppi, or pixels per inch; that is the number of pixels for every square inch of the photo. A 300 ppi image means there are 300 pixels on each square inch of the image.

Because sensors that are the same size can have a different number of pixels, measuring on the ppi scale is unrealistic. An 8" x 10" photo with a 300 ppi actually has more pixels than a 4" x 6" 300 ppi picture.

Another problem arises when you consider that printers are measured in dots per inch or dpi.  Printers use dots of ink to print, not pixels, and different printers use different numbers of dots for each pixel in a picture. The higher the dpi, the higher the quality of the print will be.

Pixels are made of various colors, contrasts, and brightness values; therefore, the more dots of varying colors and quantities, the better the image will be.

Quality photographic prints will require a printer that can print a resolution between 240 and 360 ppi, since this is the resolution required to produce a photo-quality image at a normal viewing distance. What this tells us is that we need to be aware of not only the ppi of the camera, but also the dpi of our printer in order to come up with photographic quality prints.

Sunday, April 27, 2014

Data Storage and File Formats on Digital Cameras

Exif, or Exchangeable image file format, was designed by JEIDA, the Japan Electronic Industry Development Association.

It uses the existing JPEG, TIFF Rev. 6.0, and RIFF Wave file formats, which are the standard methods of compression for digital photography. They additionally use metadata tags which have caused some discussion as to their usefulness. JPEG 2000 and PNG do not support this technology.

TIFF files provide the Exif tags' structure, and there is a great deal of overlap between the standards of the tags in TIFF, Exif, TIFF/EP, and DCF. A broad range of metadata tags appear in the Exif standard:

* Current date and time recorded on the photos are part of this information.

* Information such as the make and model of the camera.

* Orientation, aperture, focal length, film speed, shutter speed, and metering mode are included, even though they vary with each image.

* Thumbnail prints allow immediate viewing of the picture on the LCD screen.

* A few cameras support a GPS receiver.

* Copyright information and descriptions are available on higher-end cameras.

Most of the older programs do not recognize Exif date, which is embedded within the image file, while many of the recent programs recognize it and will retain the majority of it when writing to a modified image. Some recognize it and display it beside the images.

File formats are one way of recording information for storage in digital cameras; it specifies the use of TIFF or JPEG. TIFF is the highest quality, and JPEG is used to save space at the cost of quality. JPEG is the only format available in many of the less expensive digital cameras.

CCD-RAW is another format you may encounter; the data is processed minimally and must be converted to TIFF or JPRG in order to be edited. This format is not standard.

Thursday, April 17, 2014

How To Select Underwater Camera

Buying digital underwater camera can definitely make you envision taking pictures in a much different light (literally and figuratively). Today, even non-waterproof cameras can be transformed into underwater cameras by way of waterproof housing and casing. Additional accessories and peripherals for underwater photography pave the way for inspiring and interesting pictures you can capture and share with friends and family.

Today's digital underwater camera is jam-packed with so much technology and new features that you just may become overwhelmed with what to look for. Consider the type of photography you prefer to do first. If it is something you wish to use to capture more casual images underwater, for example of family and friends swimming at the pool or beach, purchase a camera with face-detection tool. It'll aid you very much in catching the expression on people's faces underwater without having to zoom in on them and missing the moment.
Camera models with the tap technology like the ones from Olympus are also great to use. It enables users to merely tap the side of the camera to shoot the photograph instead of struggling about underwater for buttons to click.

For more casual pictures like family or holidays, a digital camera with face detection and tap technology are great to have. These can prove convenient when you are underwater holding your breath, and attempting to get the expression on your kids' faces when they're swimming underwater. Tap technology, available in waterproof digital cameras similar to some Olympus designs, is when a camera's side can be merely tapped to take photos instead of making you push countless buttons to take a photograph.Your favorite pictures should always matter a lot when you are in the market for the finest digital underwater camera for you personally. Will you be shooting under the surface photographs of your children as they are learning to swim in the pool? Are you a newly certified diver who wants to record your first real foray under the surface? Or do you simply love the notion of a camera that can turn into an underwater one for use during out of town trips?

It should be also essential to read up on the positives and negatives of each model to help narrow down your choices. Some could be affordable but offer fewer features compared to similar cameras. Alternatively, a digital camera could possibly be jam-packed with extras but may be way out of your budget. Learn how to weigh the positive and negative aspects of waterproof digital cameras so you can still get the right possible deal.

You'll notice lots of waterproof cameras and lenses to pick from these days. The bottom line is, you should do some reading before choosing one for yourself. In the end, the digital underwater camera that can work best for you is the one which will conform to your way of life, preferences, and price range. While you are at it, also consider useful features similar to fast shutter response, longer battery life, and lighting in low marine light especially if you want to shoot sea flora and fauna after the sun has set.

Owning a digital underwater camera can drastically change the way you are taking photos. Many think this is a tool merely intended for divers and marine life fanatics.

Visit for Waterproof Camera reviews

Wednesday, April 16, 2014

Counting Pixels

Smaller is not always better, especially when you are dealing with pixels.

Varying in size from one manufacturer to another and even from one camera to another, pixels are the little critters found on your imaging sensor, which are the components that record light on most digital cameras. It therefore makes sense that a larger pixel can record more light if they are larger.

Two sensors with the same number of pixels would be compared as follows: The one with the larger pixels would take a higher quality image than the sensor with the smaller pixels. Scientists have gone crazy reducing things to digital size; a smaller sensor with the same number of pixels would, of course, require smaller pixels.

The smaller sensor may be more efficient because of its size, but it won't usually produce the same quality images as the larger sensor with larger pixels will. Miniaturization isn't always the better way to go.

Digital single lens reflex cameras (SLRs) have a better quality of image than compact or point-and-shoot cameras because they have an imaging sensor close to the size of those found on a 35mm film camera. Even the high-end compact cameras costing up to $1,000.00 use a sensor about 1/1.8" or 5.5mm x 4.1mm. Even with a 3-, 4-, or even 5-megapixel sensor, they can't create photos comparable to the 3-megapixel SLR.

Because the technology is relatively new, many customers are confused by pixel numbers, and manufacturers aren't completely upfront when the talk about pixels either.  A camera with 4.3 million pixels may only use 4 megapixels to actually record light information for the image. These are described as the "effective" pixels, and you have to look really hard to find where the manufacturer discusses these in your manual.

However, this is the number you want to use when deciding on the camera's pixel size. If a camera has 3.1 effective megapixels, yet is advertised as a 3.3-megapixel camera, it is still only a 3.1-megapixel camera.

The law requires that the effective pixel count be advertised along with the pixel count, but this isn't always true, so look for it in your cameras manual.

Monday, March 31, 2014

Connecting to a Computer

Connecting directly to a computer for data transfer is available with many digital cameras; this creates the ability for the photographer to choose only the best images for printing. It also allows the photographer to print and store hundreds of images, which would require many rolls of film and necessitate extensive storage for negatives.

These are some of the methods of connecting:

* Early in production they used a PC (personal computer) serial port.

* USB is the most widely used method now; a universal serial bus is now a standard interface device.

* FireWire ports; this is a copyrighted name of Apple Inc for the IEEE 1394 interface.

* USB PTP (picture transfer protocol) may be used as a mode of connection rather than the USB MSC (mass storage device); some computers offer both methods.

* Some cameras use wireless connections.

* A card reader is a standard alternative. It is capable of reading many different types of storage media, and it allows high speed transfer of data.

A card reader also eliminates draining the battery in the camera during the process of downloading data. The power is taken from the USB port, not the camera.  This can be inconvenient if only one reader card is used to directly access the images to several storage media, which requires moving the card back and forth between media.

Many cameras are now set up to transfer data directly to the printer without the use of a computer. There are several devices that have digital cameras built in, due to limited storage and with the emphasis on convenience; the quality of the images is usually poor, cell phones are the most common of these items. PDAs, laptops and Blackberries are others in this class; even some camcorders have digital cameras built in.

Thursday, March 13, 2014

Compromises Made by Your Digital Camera

The means your camera uses to take images and translate them from the image sensor to the computer or printer may not be hindered by the compromises it makes during the process.  You will only know this when the photos are being viewed at the time of transfer.

Storage is one of these compromises; digital images take a great deal of space for storage. They need to be managed in a way that ensures enough images can be stored before they need to be downloaded from the camera.

Cameras use different levels of compression to downsize the images for storing them in memory. JPEG is the most widely used standard, it removes information that can't be seen by the human eye anyway. The higher the level of compression, the more information is deleted.

At the higher compression setting, blocks start to appear in the images. This begins to degrade the image quality, making the resulting file size extremely small.  If quality is the most important consideration, avoid JPEG compression. 

The mid- to high-end digital cameras offer different forms of compression, which don't delete any information, by using mathematical algorithms. They compress the file and save it either in TIFF format or as RAW files, which contain only the information the sensor captured with no in camera processing.

Larger file sizes are the result of this lossless file compression format. However, the higher image quality and post processing flexibility makes up for the loss in image storage space.

Another compromise made in digital cameras is the in-camera processing; these create predefined results. Some cameras have sharpening filters which restore the contrast that is lost in edge details when the image goes through the various optical filters.

This process of sharpening in the camera reduces the ability to sharpen the image once it has been downloaded to the computer. Oversharpening can create unnatural and harsh edges and may even cause shifts in color.