I own a Fujifilm Finepix s2980 and I can't find the long exposure. I would like to know if I have this feature or not in my camera.
According to these specifications published by Fuji, the longest shutter speed possible in Auto Mode is 1/4 second. In all other modes the longest possible shutter speed setting is 8 seconds.
The instructions for manually selecting the shutter speed using Shutter Priority Mode can be found on page 27 of the S2900 Series Owner's Manual. Instructions for controlling both shutter speed and aperture in Manual Mode are found on page 29.
Many similar cameras limit exposure times due to the smaller sensor size. The longer the exposure, the warmer the sensor heats up. This causes increase noise in the image. All other things being equal smaller sensors are inherently noisier than larger ones because they collect less light than the larger sensors can. Since image noise is a result of a low signal-to-noise ratio, the less light (signal) that is collected, the lower the SNR will be.