Start with the highest to end up with the best
While shooting:
use the highest MP camera you can afford (I've just ordered the Oly C5050)
use the best image FORMAT possible - TIFF is great but not often practical. JPEG is the most common. The new cameras even do RAW now.
If using JPEG use the highest setting possible i.e. LEAST COMPRESSION. Digicams generally use the term HQ or SHQ.
Shoot in the largest size or DIMENSION - this varies from camera to camera - Sony's like the computer format dimensions ie the P5 uses 2,048 x 1,536, the Oly 5050 2,560 x 1,920 and even has a 3/2 size of 2,560 x 1,696
Post: Once the pic is on the computer
use an image editing program like Photoshop to change the RESOLUTION of your pic. Most cameras will give you picture by default of W x H and resolution of 72dots per inch (dpi) - this is screen resolution - great for emails lousy for printing, not print resolution. Optimum print resolution is 300 dpi. Most glossy dive magazines use about 200 dpi.
When you change resolution to 300dpi make sure you keep the dimensions the same as the original. For example if the original was 2,560 x 1,920 @ 72dpi and you change the res to 300dpi Photoshop will by default increase the dimensions or number of pixels horizontally and vertically to match. In this case simply put the original values back again ie 2,560 x 1,920. You will notice the PRINTABLE SIZE change to a smaller one - in this case from a massive 90.31 cms (35.556 inchs) x 67.73 cms (26.667 inchs) to 21.67 cms (8.533 inchs) x 16.26 cms (6.4 inchs). So a 5MP image can print at 300 dpi a true size of about 8 x 6 inchs.
Change the COLOUR MODE from RGB (again screen mode - great for emails) to CMYK - the native printing colour system. You'll need to do this especially if you're sending your award winning photos to be printed in a dive mag.
Next save this in a file format that is uncompressed - like TIFF or Photoshop (PSD). Each time you save a JPEG, contrary to popular belief, it re-interprets the image with the compression algorithm which can cause noticable artifacts.
Do all your colour correction, touch-up, contrast and adding the fish that wasn't there using this file.
Try not to enlarge (zoom in) the picture to avoid softening. It's the computer adding picture information that is not there by interpolating the information from around it. You can't get something out of nothing. This is what the gimmicky 'Digital Zoom' in digicams do. Except I'd rather use the more sophisticated algorithm of Photoshop and number crunching capability of a 2GHz Pentium4 do that than a camera - if at all I need to.
Now if you print your image you should get the best quality possible
