If you are looking for something like Fraps for Linux you can try:
Because ffmpeg is no screen recording tool...it just also can do it. But the main purpose of ffmpeg is video encoding. So that is what it's commands are optimized for, making it easy to give the exact details how you want your video encoded. If you want something simple have a look at frontends like recordmydesktop
When I was using Windows I typically used CamStudio which is free and open source and always worked okay.
On Linux I use gtk-recordMyDesktop.
Oh, ok! In that case, I used to use recordMyDesktop in the past. Looks like some new options have appeared since then.
The camera is a 5MP Omax A3550U 5mm microscope camera. The Linux version of the camera software, ToupLite is pretty basic, though the exposure, contrast, brightness, etc. settings are great. However, the video capture is terrible despite the live view frame rate being good enough not to notice lag in most cases.
Looking for a solution to the bad frame rate with video capture in ToupLite, I came across RecordMyDesktop which works like a dream!