Don't send a picture the size of a poster to show at the size of a stamp!

The photo gnomes are still churning out new cameras and camera phones with ever mightier megapixel counts. Wonderful of course. But more megapixels doesn't necessarily mean better pictures, and it certainly means huge files.

If you try to send multi-megapixel pictures directly from your camera phone, or even from your desktop, your mailbox will probably resize or refuse them. Even if you succeed in sending a large image file, your recipient may not thank you. The pictures will take ages to arrive, and may clog up their mailbox.

Beware of overweight pictures even if you're posting to a gallery, blog or website.

If you can't make your pictures small in the first place, slim them down. For multimedia messaging direct from a camera phone, your photo will doubtless be automatically sized for sending. For email or website graphics, an inexpensive desktop art editor like Photoshop Elements makes image reducing easy.

Here are two very common misconceptions that could cost you money - or friends!

WRONG IDEA 1

"The size of my picture is the size I can see on my screen."

Actually a digital image can be three kinds of 'small'.

Your picture can be small in dots, inches or bytes.

1. DOTS. The image contains a limited number of computer screen pixels or printer dots. For instance, a one megapixel photo is made of a million pixels. A megapixel isn't exactly small, but the dots can be squeezed together to look small, as they do on your phone screen. Alternatively they can spread out wide to display at a larger size, as they would if you printed the same photo at poster size.

2. INCHES. The picture is displayed at small size - as measured in inches on a screen or on paper.

3. BYTES. Thirdly, an image can make a small computer file - as measured in bytes. This is something different again. Of course the more pixels you have, the bigger your file. But various compression techniques, plus the content of your picture can make a big difference to your file size.

Result. In a desktop art editor, there are more ways than one to slim down a photo for the post. 'Reduce image size' will shrink your picture only by reducing the number of pixels it contains.

TWO WARNINGS
when you reduce an image size

Save the result with a new name, or else it will replace your original and you'll lose it.

Conserve the aspect ratio (relationship of the sides) or else your portraits could look like reflections in a fairground mirror!

Start the reduction process by viewing your original at 100%. That's the size it will look on most computer screens. See if you can crop it first.

Cropping is a vital step if you want to create an image with impact. Automatic processing will only reduce the whole scene. Only you can home in on the most important part of your picture. Cropping to that not only adds emphasis and reduces size. One bold simple shape makes the image easy to recognise at very small sizes, for instance, as a mini-portrait for an address list icon.

...Now rush out and buy Photoshop or its cheaper but still excellent cousin Photoshop Elements! Both have a marvellous menu item called 'Save for Web'. This will not only reduce the image dimensions in pixels. There are several options for differing degrees of compression, plus all kinds of other aids.