Understanding Your Digital Camera-3

You've read about film cameras up till now. You've also probably been thinking about your own digital camera and compared it to the descriptions of the film cameras in the last lesson. It is time to learn how the digitals capture images and then stores them for retrieval later... just like film.

We know that 35mm film cameras used film that actually was 36mm x 24mm imaging area. You probably remember looking at negs and tried to make out what the picture was. Slides we better since they were positive... but still pretty small to figure out if the image was anything worth keeping.

Then before you know it, digital cameras replaced all of that uncertainty almost overnight. No more running to buy film or even looking for the expiration date... in digital, there isn't an expiration. And you almost never run out of film, uh, space on your memory card.

Yes, we have arrived at a new age of digital photography. But how do they actually capture images anyway? Well, there are a number of things that make these cameras different from their predecessors. The first obvious difference is the image sensor that replaced light sensitive film. This sensor has grown in size, speed and ability since the early years of 1.3 and 2.1 megapixel cameras. The interesting thing that really makes a big impact is the physical sensor size. The very earliest sensors were much smaller than a thumbnail. They were testing the market to see if people would flock to these portable imaging systems- and they did! Soon there was more and more demand for higher quality, higher resolution cameras... and so it started.

Earlier, we learned that film was 36mm x 24mm. The
sensors are getting to be that big ...slowly. So if the sensors have a smaller imaging area than film and you are using one of your lens from your film camera on your new
digital SLR, the images are going to have a different millimeter range. You might notice that the wide angle lens isn't as wide but your tele-zoom looks actually more powerful. If you are using a "point and shoot" digital, this may not be the case.

So the image is captured by the sensor... then where does it go? The storage card inside the camera stores the pixel data or image in its memory. Most of these cards have plenty of room currently because the average digital is 6-8 megapixels. The cards didn't have to be as big when the 2-3 megapixel cameras were popular because the file sizes were smaller. More megapixels equals more file size. Actually the imaging market drove the memory producers to make larger capacity cards!

As you know, the images are temporarily stored on the memory card. Then the images are transferred to your computer on its hard drive where you may print, share and store your many pictures. It is extremely important that you do not store your images on your camera's memory card. The longer you store images there or the more images on the card, the better chance there is for your to mistakenly delete them or loose them to static electricity which erases the card! So, make sure you are aware of the importance of off-loading images to your computer whenever you use your camera. Make a back-up of these images often...