Resolution and Compression

Resolution | Compression | Optical vs. Digital Zoom

For optimal image quality, select your cameras least compression and highest resolution (highest number of megapixels) settings.

Resolution - Image Size / Pixels
In digital photography, resolution is a measure of how many pixels make up a digital picture. The more pixels a camera has, generally the better the quality of its photographs, though other factors also greatly influence picture quality. Pictures taken at smaller sizes require less memory, making them suited to distribution by email or the web.  Conversely, the larger the image, the larger the size at which it can be printed or displayed without becoming noticeably “grainy”.  (Better to take a large picture, for quality, and if you wish to use it for email, use software to create a new copy of a smaller size.)  (Always keep the original in its original size.

**Camera Settings (Large)
M1 (Medium)
M2 (Medium 2)
S (Small)

Low compression = better image quality

Digital cameras provide a variety of compression levels: Super Fine, Fine, Normal and Basic. The terms vary among manufacturers. The Fine or equivalent setting produces the least compression and best image quality.

Compression

Compression/quality — Sets the compression for recording images typically Fine (best image quality for the file size selected), Normal (very suitable image quality) and Basic (least quality though images may be perfectly suitable for email or posting on a web page).

Compression settings may have other designations such as best, better, good; standard, high, super high.  (Also see digital camera file formats.)

** Example Camera settings
Extra/ Superfine
Fine/ Fine
Norm / Normal
Basic
** Camera Terms  varied with manufacturers however, they all refer to the QUALITY AND SIZE of the picture.

 

 

 

 

 

 

On the left, 10:1 JPEG compression. On the Right 40:1 compression.
Uncompressed the image would look virtually identical to the 10:1 JPEG on the left

Digital Zoom and Optical Zoom
Most cameras have both optical zoom and digital zoom. Optical zoom works just like a zoom lens on a film camera. The lens changes focal length and magnification as it is zoomed. Image quality stays high throughout the zoom range. Digital zoom simply crops the image to a smaller size, then enlarges the cropped portion to fill the frame again. Digital zoom results in a significant loss of quality as is clear from the examples below. It's pretty much a last resort, and if you don't have it in camera, you can do a similar job using almost any image editing program.

Comparison of optical zoom and digital zoom

Other places to find information on Picture Quality.

Kodak offers another great explanation of Picture quality Click here!