Highest resolution, lowest compression is ideal. However, it also eats memory quite quickly.

I therefore often find myself shooting at high resolution with medium compression, or medium resolution with lowest compression. On my Canon S10, these two configurations seem to produce images about the same size (in Kb).

My question is: Which is better? I'm new to digital photography and haven't yet figured it out. My main use is for web pages as well as the occasional print via online photo processor.

My first instinct is to use high resolution and medium compression - this gives me more pixels should I need to crop. On screen I can not tell a difference between high and medium compression - but will 5x7 and 8x10 prints be significantly degraded by the higher compression?

-- Greg Philmon (gphilmon@yahoo.com), June 16, 2000

Answers

Greg, Your first instinct is correct--better to use high resolution and low compression, but you don't mention which camera your're using or which storage medium your're using. At work we use everything from the $40k Canon/Kodaks to the Kodak 290 and the Nikon 950. We archive all of the storeable photographs either to cd or a dvd jukebox as 8x10 300ppi tiff images. From this we can satisfy any customer whether it be a newspaper, a magazine, or a web site. We simply make size and resolution adjustments based on what is required. What image editing software are you using? Do you have a CD writer? This is an ideal format right now for storage. It is inexpensive, and you always have a high resolution image available without having to save to your hard drive.

Fred

Imaging Services NASA Marshall Space Flight Center

fred.deaton@msfc.nasa.gov

-- fred (fdeaton@hiwaay.net), June 16, 2000.

Another cool software which works for even larger format and help save the space is Genuine Fractals at: http://www.adobe.com/products/plugins/photoshop/fracprint.html

Now you can start w/ medium resolution.

-- Tanasit Siriluck (tanasit@flashcom.net), June 18, 2000.

A few days with my Nikon Coolpix 990, I did some testing to find out the best combination of "resolution" and "compression" which Nikon refers to as Size & Quality. My goal is to have the acceptable print quality for me and get the most number of images on the compact flash. I chose 3 resolutions (2048 x 1536, 1024 x 768, and 640 x 480) and 4 compression ratio (none, 1/4, 1/8, and 1/16). Total of 10 shots of the same object with lots of detais and color, then print 2 pictures per one 8.5 x 11 Epson glossy photo paper on Epson 3000 at 1440 dpi. The result: only the 640 x 480 resolution (Nikon called it VGA mode) is unacceptable because the jagged edges and fuzzy details. Next I enlarge only 2.5 % of the images where there are most details to about 4" x 4" and print out side by side. Only the highest resolution ones that hold their ground while the 1024 x 768 start to pixelate. Interestingly, the amount of picture store when setting at 1024 x 768 at 1/4 compression is the same (320 images from 128 Mb CF) as 2048 x 1536 at 1/16 compression ! So the obvious choice for me is to set at highest resolution and lowest compression. Nikon also offers a size of 3 : 2 (2048 x 1360) which give me a 40 more shots with no ill effects.

Note: jpeg compression reduces file size, but has no effect on the number of pixels of the image or on the size of the image when output on a printer or monitor.

-- Tanasit Siriluck (tanasit@flashcom.net), June 20, 2000.