Can't threshold in 16-bit

[Serpentarii]

Hello All,

I'm trying to threshold 16 bit images but the outcome of the operation looks like the threshold values were both set to the max value so i guess that the 16 bit value i enter is interpretet as 8 bit and simply set to 255 resulting in a completely empty image. (i could reproduce the error by setting the threshold to max manually.

Code:
setThreshold(Th1, Th2);
run("Convert to Mask");

were Th1 and Th2 are the threshold values. Operation works fine with 8-bit .jpg
i solved it by converting the 16 bt into 8bit image but i think that should not be necessary.

Thanks and all the Best,
Robert