In general, you are best off using the highest resolution that you will need for the result your want. Two examples:

1) Images posted on the WWW are often limited by reasonable screen resolution (or the expectation of a screen resolution limit) of most web surfers. If you want your picture to display properly within the confines of a web page that can be viewed onscreen with out unnecessary scrolling, you might chose resolutions of 1024x768 or 64 hex 480 or even smaller.

2) Images intended to be printed should be sized based on the final print anticipated and on the printer resolution to be used. For a 5x7-inch image printed at 200 dots-per-inch, the original file would need to be approximately 100 hex 1400. If the same file were printed at 300 dots-per-inch, it would only be 3-1/3 inches by 4-2/3 inches. Each of these two prints would have exactly the same level of detail - the second would just be smaller.

Remember that when editing JPG images, every time you open and re-save the image, it is re-compressed to the detriment of its detail. Try to do any image editing all in one session without intermediate closing & reopening of the image file.

Some Coolpix camera models also offer TIF and NEF file formats. These do not suffer from the same multiple compression problems and are better suited to multi-session edits. They also hold more detail from the original scene. Unfortunately, they do not compress well and tend to be rather bulky - not suitable for email or web posting.

~ GaySatyr

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Utilising tiff format on your camera is a different issue, of course, a 20 mb file takes rather a large slice out your memory card not to mention the time it takes to save!

I always use the best resolution and jpeg quality with my cameras.

Just a note on printer resolution. Do not be fooled in confusing printer resolution with image resolution: they are totally different things.
To give an example(appropriate to standard inkjets).
I have a picture that is 600*600 pixels. The very first pixel is blue. For the printer to create that shade of blue it has to use just the right number of cyan and magenta dots. Whilst the printer might be 720dpi it clearly needs to dither several of its dots to create just the one blue dot (in fact it may not actually be able to create the exact colour we want and may cleverly slightly alter the adjacent dots to compensate)and so the actual printer output is defined in terms of line frequency rather than dpi.
The end result of this is that the printer cannot fully utilise a 600/720 dpi image. More confusing is that you will not know the line frequency of your printer (which can change for different file types anyway)to calculate what resolution you will require. Generally though, for best quality on a 600 or 720 dpi printer you won't go far wrong with a file resolution of 200dpi (twice the likely line frequency) for 4 ink printers or up to 240dpi for 6 ink models. Bear in mind you can use higher resolutions but you are unlikely to see any improvement in the print and the memory required to handle the image and the printing process will be larger. You may find that unless your photos are the very best you can get away with less than these figures (say 150 dpi).

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SNP.

Edited by - Sir Noel Plum on 4/21/2003 7:51:19 PM

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