[HOW TO]Remove motion blur on the camera by forcing a low exposure time

As anyone who has setup the AXIS Camera knows, there is no way to set the exposure time explicitly from the setup web page. I needed to force the exposure time down in order to keep tracking this years target while moving, so I looked around on the file system and figured it out.

There are three values that have an available settings of “Hold Current” that are saved between power cycles. These values are simply stored on the file system under /dynamic/image.conf (it may be slightly different, but I don’t have the camera with me at the moment). It is a text file with three lines:

HOLD1=x.xxxx
HOLD2=y.yyy
HOLD3=zzz

The third line is the exposure and is a number between 0 and 1000 (I don’t know if that’s inclusive or not). I don’t know what the number represents, but I believe it to be milliseconds (lower is a lower exposure time).

To force the exposure low:

  1. Set the exposure to Hold Current.
  2. Go to the script editor (I forget where it is right now, but it’s near the same place you create backups).
  3. Find /dynamic/image.conf
  4. Set HOLD3 to the desired value (150 was a good value for me).
  5. Save the file.
  6. Power cycle the camera.

This doesn’t work every time, and seems kind of random, but once it works, it will stay between power cycles. Once you get it working I recommend backing up the settings and not changing the exposure programmatically.

With this change I was able to get tracking working at 8fps even while wildly flailing the camera around :P.

Great tip Michael!

We’ve been looking for a solution for this for quite some time.

Thanks for sharing!

Michael-

I can’t find this file. Is it on my PC? On my cRIO?

If it is on my cRIO, how do I access the file system on that computer? Is there a tool for connecting to it’s operating system directly?

This was for last years camera. The new 2011 camera seems to work fine without this change.

And… we have last year’s camera! If anyone can help here, this would be much appreciated.

I got the impression that they were discussing files which reside on the camera itself. I’m not sure how to go about accessing them, it might be possible to ftp into the cameras ip address? I don’t recall seeing a file explorer accessible through the web based config. page.

These files are on the camera. You should be able to ftp into the camera. Be very careful not to change or delete other files.

Greg McKaskle

I was able to FTP to the camera. I spent a lot of time poking around, but I did not find /dynamic/image.conf

Does anybody have a more precise location for this file? We really need to turn the gain down on our camera.

Thanks,
Geoff Nunes

I’ve never done the file change either. If I want to shorten the exposure, I point the camera at a bright light source with it set to auto, count to five, then set to hold and point at the field. This is not a very repeatable calibration, but you can use the same principle.

If you are doing this, keep in mind that the exposure calculation is probably based on area. A single spot of bright light will likely not cause the exposure to change. A big spot of bright light probably will. If I have time, I’ll look on the cameras for the file mentioned earlier and give a more precise path.

Greg McKaskle