Smallest organism possible

Hello, I would like to know the size of smallest organism that Zooscan and Zooimage can separate (vignetes) and identify. I am using Zooimage for Macrophotography, and I don't know how can I change the "threshold": there are only 2 options for the range...
Thanks

Dear Marc and Zooscan users
As a follow-up to Masami's query -- we are interested to learn how "small" Zooprocess can go, i.e., what is smaller size range of particles the software can handle. We have been working with preserved samples collected with 150 or 200 micron mesh nets, meaning that most organisms are bigger than 250-300 microns. What about small-sized mesh zooplankton? Has somebody ever tried to scan microzooplankton? Also -- can somebody guide us on how to decrease the size threshold for particle segmentation? I could not find any detailed info on the Zooprocess manual.
Thanks,
Rubens Lopes

hello,
please disregard my previous question -- Sabine Schultes has already adviced me! Here I go to the microzooplankton trial.
Rubens

Dear Rubens, Eduardo,
I am just back from a cruise. The smallest size depends on the ESD min setting of Zooprocess. You can adjust it in the "Edit configuration file" menu of the software. We have scanned stained and unstained ceratiums and got very good results with 2400 dpi images and ESD min set to 150 µm. The major problem is the contamination from particulate matter and detritus. Another concern comes from the few pixels of these small organisms limiting the details.
Best regards
Marc P.