User`s manual

Choosing Your Application AXIS 2120 User’s Manual
30
Picture frequency for Networking Applications
When used in a TCP/IP networking environment, the AXIS 2120 delivers up to 25/30
(PAL/NTSC) images/second; where the actual image frequency is typically limited by:
your computer and browser
the chosen image resolution and compression
the lighting conditions at the point of installation
available network bandwidth
the complexity of detail and color variation within the image
Important!
Image Compression Ratios
Although the file size of a JPEG-compressed image depends upon the actual content of the
image, images containing a lot of detail generally generate larger files. Image quality is
largely controlled by the level of compression; where high compression yields small files,
and low compression maintains higher image quality at the expense of larger files. The
table below is derived from real-life tests, and defines the average file sizes for each
supported image resolution:
* Maximum performance for a single viewing client.
** Interlaced image
Note: Using a modern computer will avoid introducing any unnecessary constraints on the imaging fre-
quency.
60Hz and 50Hz variants of the AXIS 2120 are available to accommodate the different power supply fre-
quencies found in the USA and Europe.
The 60Hz variant delivers a resolution of 525 lines at 60 half-frames per second and is suitable for use in
the United States; whereas, the 50Hz variant delivers 625 lines at 50 half-frames per second and is
appropriate for use in Europe.
60Hz (NTSC Countries) 50 Hz (PAL Countries)
Resolution Filesize (kb) Max fps* Resolution Filesize (kb) Max fps*
4CIF (704 x 480) ** 7 - 150 10 4CIF (704 x 576) ** 8.5 - 180 8
CIF (352 x 240) 1.4 - 40 30 CIF (352 x 288) 1.7 - 50 25