ASI Camera FAQ
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1. Why can't my ASI120MM/MC run up to 30fps at 1280X960?
Firstly make sure the value of “Auto FPS Adjust” value is correct, this is called “USBTraffic”
under Firecapture. 86% corresponds to 30fps, this value of different computers differs slightly,
you can try to turn up slowly by yourself. Fluent images and no broken frame indicate that your
computer have enough bandwidth for current FPS. Most computers can run steadily at 30fps,
some computers can reach to 34-35fps.
Secondly, ensure that the exposure is less than 1/30 second. The exposure time will limit FPS, for
example, the FPS will decrease to 1FPS when exposure time is as long as 1 second.
2. My ASI120MC can preview up to 30fps at 1280X960, but it becomes 15fps when recording. It
drops frames like crazy?
It’s good to hear that your computer can preview up to 30fps, this means your computer’s USB
bandwidth is wide enough to run ASI camera. The fps drops when saving is because the low
speed of your harddisk. It always happens in laptop which usually comes with a low speed
harddisk.
Let’s calculate the data size transferred to hardisk every second. A color video’s each pixel
contains 3 byte which correspond to R, G and B, so 15fps corresponds to disc writing speed of
1.2M*3*15=54M/s. The writing speed of general hard disc is 30-50M/s. We recommend high
speed SSD solid hard disc if you require the fast recording speed, for its writing speed can reach
upwards of 100M/s.
We recommend you can try to record the video data in RAW format which is only 1/3 size of color
video. Then debayer the raw data in stack software like AS!2.
