The amount of detail that a camera can capture is called the resolution, and it is measured in pixels. The more pixels a camera has, the more detail it can capture and the larger pictures can be without becoming blurry or “grainy.” High-end consumer cameras can capture over 12 million pixels. Some professional cameras support over 16 million pixels (megapixels), or 20 million pixels for large-format cameras. For comparison, it has been estimated that the quality of 35mm film is about 20 million pixels.

Exposure and Focus

Just as with film, a digital camera has to control the amount of light that reaches the sensor. The two components it uses to do this, the aperture and shutter speed, are also present on conventional cameras.

Aperture: The size of the opening in the camera. The aperture is automatic in most digital cameras, but some allow manual adjustment to give professionals and hobbyists more control over the final image.

Shutter speed: The amount of time that light can pass through the aperture. Unlike film, the light sensor in a digital camera can be reset electronically, so digital cameras have a digital shutter rather than a mechanical shutter.

These two aspects work together to capture the amount of light needed to make a good image. In photographic terms, they set the exposure of the sensor.

In addition to controlling the amount of light, the camera has to adjust the lenses to control how the light is focused on the sensor. In general, the lenses on digital cameras are very similar to conventional camera lenses — some digital cameras can even use conventional lenses. Most use automatic focusing techniques.

The focal length, however, is one important difference between the lens of a digital camera and the lens of a 35mm camera. The focal length is the distance between the lens and the surface of the sensor. Sensors from different manufacturers vary widely in size, but in general they’re smaller than a piece of 35mm film. In order to project the image onto a smaller sensor, the focal length is shortened by the same proportion.

Focal length also determines the magnification, or zoom, when you look through the camera. In 35mm cameras, a 50mm lens gives a natural view of the subject. Increasing the focal length increases the magnification, and objects appear to get closer. The reverse happens when decreasing the focal length. A zoom lens is any lens that has an adjustable focal length, and digital cameras can have optical or digital zoom — some have both. Some cameras also have macro focusing capability, meaning that the camera can take pictures from very close to the subject.

Digital cameras have one of four types of lenses:

1) Fixed-focus, fixed-zoom lenses – These are the kinds of lenses on disposable and inexpensive film cameras — inexpensive and great for snapshots, but fairly limited.

2) Optical-zoom lenses with automatic focus – Similar to the lens on a video camcorder, these have “wide” and “telephoto” options and automatic focus. The camera may or may not support manual focus. These actually change the focal length of the lens rather than just magnifying the information that hits the sensor.

3) Digital-zoom lenses – With digital zoom, the camera takes pixels from the center of the image sensor and interpolates (alters) them to make a full-sized image. Depending on the resolution of the image and the sensor, this approach may create a grainy or fuzzy image. You can manually do the same thing with image processing software — simply snap a picture, cut out the center and magnify it.

4) Replaceable lens systems – These are similar to the replaceable lenses on a 35mm camera. Some digital cameras can use 35mm camera lenses.

Storage of Images

Most digital cameras have an LCD screen so you can view your picture right away. This is one of the great advantages of a digital camera — you get immediate feedback on what you capture. Of course, viewing the image on your camera would lose its charm if that’s all you could do. You want to be able to load the picture into your computer or send it directly to a printer. There are several ways to do this.

Although most of today’s cameras are capable of connecting through serial, parallel, SCSI, USB, or FireWire connections, they usually also use some sort of removable storage device. Digital cameras use a number of storage systems. These are like reusable, digital film, and they use a caddy or card reader to transfer the data to a computer. Many involve fixed or removable flash memory. Digital camera manufacturers often develop their own proprietary flash memory devices, including SmartMedia cards, CompactFlash cards and Memory Sticks. Other removable storage device include floppy disks, hard disks (external, or microdrives), and writeable CD’s and DVD’s.

Regardless of what type of storage they use, all digital cameras need lots of room for pictures. They usually store images in one of two formats — TIFF, which is uncompressed, and JPEG, which is compressed. Most cameras use the JPEG file format for storing pictures, and they sometimes offer quality settings (such as medium or high).

To make the most of their storage space, almost all digital cameras use some sort of additional data compression to make the files smaller. One compression routine takes advantage of patterns that repeat. The image can be reconstructed exactly as it was recorded, reducing the file size no more than 50%, often much less. Another compression routine called irrelevancy eliminates some of the more meaningless data, taking advantage of the fact that digital cameras record more information than the human eye can easily detect.

The type and format of the backup storage medium used effects the future growth, investment protection and performance of the company. The restore & backup strategy are dependent on the format of the tape medium being used. According to the findings, more than five hundred thousand drives of SLR are installed in Servers of iSeries around the world. The SLR tape format is best suited for the “iSeries” and it protects the high volumes of data with fast recovery and backup performance. The SLR is the abbreviation of “Scalable Linear Recording” and Tandberg Data introduced the first generation SLR-1 tape in the year 1987.

Tandberg is one of the major manufacturer and supplier of the backup tape media products. The major tape formats of Tandberg are the Linear Tape Open (LTO), Digital Linear Tape (DLT) and the Scalable Linear Recording (SLR).

The product line of the Tandberg includes the backup tape libraries, tape autoloaders, media and backup data tape drives.

At first the SLR backup tape was based on the technology of QIC (Quarter Inch Cartridge). Afterwards the technology used was the SLR (Single Channel Linear Recording). Then new technology MLR (Multi Channel Linear Recording) was added and then to its present form of the SLR tape format. The SLR tape media products are highly scalable, reliable. They are also compatible both forward and backward with the other generations of SLR format.

In the SLR-7 tape the recording of the data is done on 2 tracks and is recording is done in parallel. While in SLR-60 & SLR-100, the recording is done on 4 tracks. The data is recorded on the media in such a form that incase of degrading of media, the data could be read in the operation of restoring. The attributes and technologies that enhance the speed of the SLR tape are the “auto sense function”, “inline compression”. The data buffers are also large in the SLR technology. The SLR-1 tape format gives the tape solution for entry level and at a low cost. Since the year of the introduction of SLR, about 2 million drives of SLR have been installed by the companies worldwide.

The cost of ownership for the SLR tape format is very low because it has low rate of failure which is about 1.5 percent. The SLR is best for those enterprises where the field maintenance is low.

The SLR-60 has 30 GB native capacity and 60GB of compressed recording capacity. The data transfer rate is 4MB/sec with 8MB/sec of compressed rate. The transfer rate per hour is 15GB/hour with compressed rate of 30GB/hour.

The SLR-100 has 50 GB native capacity and 100GB of compressed recording capacity. The data transfer rate is 5MB/sec with 10MB/sec of compressed rate. The transfer rate per hour is 18GB/hour with compressed rate of 36GB/hour.

The reliable and robust backup tape format choices for the small & medium business enterprises are the SLR-60, SLR-100 and the SLR-140 backup tapes.

The SLR technology has the capacity, technology and the features to fulfill the future’s data backup demands and requirements of the companies in efficient and cost effective manner. The roadmap of the SLR tape format has the ability to meet future demands for backup data storage. The roadmaps do tend to change with the passage of time and when the future generations come close to the existing and the present generations.

For more details and online order, please visit www.tape4backup.com

Unlike the 35mm film camera which differed only in the
number of shots and manufacturers, different digital
cameras use different storage media.

This is usually the case for different camera manufacturers
as some brands prefer to have a proprietary storage medium
for their cameras.

Aside from the different types of storage media, they also
differ in the amount of memory they can handle. Today’s
cameras eat up more memory which is why bigger memory is
the order of the day especially for professionals.

Here are some of the most popular storage media used by
digital cameras today:

1. Compact flash

- this is perhaps the most common storage device for
digital cameras, especially high-end ones like digital
SLRs.

Compact flash memory comes in two flavors: Type I and II.
Most cameras accept Type I although the Type II varieties
have a higher capacity.

2. Memory Stick

- this is a proprietary storage media produced and
developed by Sony not only for their digital cameras but
also on their other products.

Early Memory Sticks were able to store only up to 256MB
although Sony has already come up with the Memory Stick Pro
which has capacities up to 1GB.

3. Secure Digital (SD) and MultiMedia Cards

- are yet other varieties of storage media. Aside from
digital cameras, they can also be used on a host of devices
such as mobile phones.

These varieties are the smallest among storage media
especially when the micro SD memory was introduced to the
public. The SD card and the MMC (MultiMedia Card) are
basically the same except for the fact that SD cards have a
write-protect switch to protect the data that is stored
inside.