Digital Cameras

By Mark Mayhew

Last Month we talked about scanners in some detail and this month my subject is that actual camera. There has probably been more advancement in digital cameras in the last four years than anything else. If you're a person who has been hooked on digital and likes to keep up with new kit and advance then you will have spent a fortune.

So first lets look at what a digital camera does. It has a lens that focuses the image on to a CCD chip. (Charge Coupled Device that turns an image into a digital picture.) Think of this device like a film. The CCD holds the image and then the electronics write this image in it's digital form to disc. No click of the shutter and no whirr as the film winds on. (It does feel strange at first.)

Yes all digital cameras have a memory card and there seem to be two main types, compact flash and smart media. Both come in a range of sizes from 2Mb up to 64Mb. Obviously the size of memory relates directly to the number of pictures that can be stored in the camera. At the moment most digital cameras are like compact 35mm with zooms built in. There are one or two that have through the lens viewing, but at an affordable price there is none that conform to what you would expect from a good SLR. They all have TTL and AF as standard. The one thing that makes them such fun is the ability to view the picture you have just taken on an LCD screen at the rear. If it was 'Pants' then delete and do it again. You can also have the LCD screen on when framing your shot, which allows you to see exactly what the chip is seeing. This is very battery intensive though.

The ability to take pictures at different resolutions is also a big bonus. Standard 640 X 480 is ideal for snaps and small prints. The detail is low and the colour rendition a little off, but a small copy to Aunty Maude in NZ would look fine. Then there is 1280 x 960. Greater detail is captured and allows a bigger print. Then there is 1600 x 1200. Here are very fine quality pictures.

People have been known to say to me that all the difference is the size of the print. Try not to think about 1280 x 960 as a size. Try to think of it more as measure of quality. The size issue comes in because your computer displays images at 72dpi (usually) so the more pixels the bigger the picture. So try to forget that and think of it more like a carpet. ?????

No seriously imagine a 1 meter square of rug. If it has 1 knotted strand per sq. cm it would be pretty threadbare. At 10 knots its getting thicker, 100 and it's getting expensive and 1000 knots per sq. cm would mean it was pure luxury. The square of carpet never changed size the number of threads did. Try and think of digital pictures that way. The higher the resolution the more detail in the picture. It's a thorny subject and one so many people seem unable to grasp.

Included with the camera will be everything you need to download your pictures to your hard drive and save them. Then you can clear the cameras memory card and start again.



This top Picture was taken at 640 x 480 resolution. The picture below it is a detail X2 to show the quality.	Here the top picture is at slightly higher resolution. The lower picture is X2 to show the quality.	Here the best quality has been used and the difference is obvious. The lower picture at X2 is still better than the other pictures at their standard size!
I have made all the pictures the same size so you can see it has nothing to do with size, but really is to do with quality.

Do you remember the old 110 cameras? They were all the rage for a short while until people realised the quality of enlargements was rubbish. Why? Because of the small negative size. Even 4" X 6" prints were struggling to show detail. Obviously as standard sizes increased to 7" X 5" people lost these cameras in the back of the wardrobe. 35mm then really became the standard as this size negative can produce quality prints up to 10 X 8. Yes I know modern film now with it's amazingly reduced grain size would cope much better with 110 film. I am sure you will all accept that a medium format camera will produce a better negative than 35mm. Yes? Then a 5" x 4" camera will produce still better negatives. Yes? OK so look at the different resolutions like that. It is to do with size, but definitely not the size you see on your computer monitor. It's about the quality of resolution of the image. Phew that's given me a headache trying to explain.

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