Tuesday, June 29, 2010

Flash Memory is a Marvel of Modern Science

The tiny memory cards that store hundreds of images for digital cameras may look insignificant at a glance but they are amazing. Their storage capacity, the speed at which they write, and their low cost make them a modern marvel. These little rectangular Compact Flash (CF) cards and SecureDigital (SD) cards are silent, have no moving parts and can withstand exposure to magnets, intense pressure and temperature extremes. Even if you accidently drop one in the toilet, it will not be damaged.


The person credited with inventing flash memory is Dr. Fujio Masuoka. In 1984 while working at Toshiba he made major developments in his work with cells that hold data and can be erased rapidly then rewritten. Flash was suggested as an appropriate name for the new type of memory because the process of erasing data from the cells was like a camera’s flash. History was made in 1984, when he presented this new technology at the meeting of the Institute of Electrical and Electronics Engineers (IEEE) in San Jose, CA.
Intel and other companes saw that flash memory had great potential. In 1988 Dr. Eli Harari and Sanjay Mehrotra, former coworkers at Intel, formed a company to produce flash memory for consumers. They founded SanDisk, which is now a world leader in digital memory devices. Sandisk’s launch in Silican Valley was perfectly positioned to take advantage of the the arrival of digital photography.
Some early digital cameras like the Sony Mavica stored images on a floppy disk. People liked this because it was easy to take the floppy out of the camera and insert it into a computer to transfer the images. The next generation of Mavica recorded images to a CD. But flash cards ultimately became the prefered media for digital cameras because they were small, had no moving parts and could be erased again and again.

Flash memory, unlike RAM (Random Access Memory) can continue to store information in the absence of a power source. This made flash memory a good choice not only for use in digital cameras, but also PDAs and video games. As consumer demand for flash cards grew Sandisk, Lexar, Kingston, Samsung and other companies offered Memory sticks, xD, SmartMedia and MultiMedia and other removable flash memory products.
As competition heated up, each brand would advertise higher capacity cards: Attention we have 4 Gigabyte cards! Look 8 GB for sale! Introducing 16 GB! Come and get the amazing 32 GB card! 64 GB cards are here! And as the public purchased the newest memory cards they found that the price paid per GB dropped steadily. That is the good news, but there is also bad news.
Unfortunately, counterfeit CF cards that look authentic but are knockoffs of the big name flash memory cards have appeared. These are passed off as the real thing to bargain hunters who later may find their joy of getting a great deal replaced by the sinking feeling that accompanies the realization that their data is lost.
Overall the invention of flash memory has been a great benefit to photography. So next time you are clicking photos take a moment to appreciate the wonders of modern technology.

Friday, June 18, 2010

What is a DSLR Anyway?

Perhaps you have heard someone mention the term DSLR and wondered what they were talking about. The "D" stands for Digital. What about the S, L and R?

The term SLR goes back about 60 years or so to the time when 35 millimeter cameras were gaining popularity. The Single Lens Reflex (aka SLR) was a significant advancement in cameras because it improved on the design of the earliest 35 mm cameras which used a rangefinder method of focusing. That was a very simple focusing system based on the range or distance of the subject to the camera. If the person you wanted to photograph was ten feet away you set the focus lever or dial to ten feet. If they were 30 feet away you set it for 30 feet. This involved a lot of guessing. Also, the viewfinder did not allow the user to look through the lens. Instead, a rather simple viewfinder gave an approximate view. As the focus was set, nothing in the viewfinder changed. Not very helpful is it?

When some engineers came up with a focusing system using a series of mirrors, so that the photographer could see through the lens that takes the photo. This new through-the-lens viewing configuration was dubbed SLR. Photographers liked the SLR cameras because the the accurate preview including the focus of the image. Another feature was that SLR cameras were made for interchangeable lenses. A busy photojournalist could carry a variety of wide angle and telephoto lenses and quickly switch lenses to suit the situation.
Another type of camera from the old days is the Twin Lens Reflex (TLR) such as the Rolleiflex, Yashikamat and Mamiya. These cameras had two lenses - one for taking the photo and one for the viewfinder. The SLR eliminated one lens which meant cameras could be smaller.



When digital photography arrived on the scene the quest for a digital version of the SLR began. Back in the early 1990s Kodak and Nikon collaborated to create the first commercially available digital SLR, the Kodak DCS-100. It was built on the platform of a Nikon F-3 body with the film drive removed. The result was a big heavy 1.3 Megapixel camera that sold for $30,000. But it was a DSLR.

One company tried for years to make a conversion kit that transformed a 35 mm SLR into a digital camera. But this never made it to the marketplace. In the end it was easier to design and build a new camera from the ground up. instead of converting an old camera to a new purpose.

As the 1990s progressed all the camera companies and some computer companies were making and selling digital cameras. Nikon marked a milestone in 1999 with the D1. This was a camera that could deliver image quality just as good as 35 mm film and it accepted the autofocus Nikkor lenses. Newspaper photographers loved it! The demise of film cameras lurked on the horizon.

Canon broke the $1,000 barrier for a DSLR in 2003 with the introduction of the Digital Rebel in 2003. The general public had a feeding frenzy taking ownership of this 6.3 Megapixel DSLR as fast as the factory could turn them out. In the years since, the price for a DSLR has come down several notches with the features have increased. In 2010 Canon is selling the 10 Megapixel Rebel XS for $499 and this includes a zoom lens!

So now we have inexpensive DSLR cameras with an accurate viewfinder and interchangeable lenses. Life is good! The advantage of a DSLR over less expensive digital cameras is the ability to change lenses. Nikon, Canon, Olympus, Sony and the major manufacturers offer all sorts of telephoto, wide angle and macros lenses. Image stabilization systems help the photographer get sharper images than ever.

The disadvantage of a DSLR is that they cost more than fixed lens cameras. But as a person gets more involved in photography they usually trade up to better equipment so that there are less limitations to what they can shoot. The DSLR with roots in the film cameras of the past is a superior product. Professional photographers, serious amateurs and occasional shooters all the enjoy the benefits of the DSLR.