Je ne sais pas.
I also notice there is some strange behaviour setting a shift when in analog scan mode, even when above the 1267x minimum mag
N.B. this is also the mag at which there are range-change relays activated (there are 4 ranges and shift is only available in ranges 2-4, I believe).
The following is an unusual set of circumstances, but an oddity nontheless; try this test:
Set instrument mag to minimum using the Cameca software (e.g. FOV ~ 2550), and leave in scanning mode.
Go into PFE analytical conditions, set 'analog scan' and set the magnification to say 4000x with any appropriate shift (e.g. 0.1,0 for Mag Analytical = 400000x; Mag Imaging can be any value) click OK.
on my instrument I hear the mag range relays click to range 2 and Mag is set to 4000x (FOV ~95um) BUT PFE returns:
"cannot set image shift (x,y) when mag is below 1267"
inspection of the shift in the 'Roller' window of peaksite confirms that no shift has been set.
Now, open 'Analytical Conditions' again and click OK (don't change any values).
On my instrument, after this second attempt, the shift is now set and PFE does not generate any warning message.
If you repeat the above test with 4000x but start with the Cameca at high mag (Say 60um FOV) , then no warning is generated and the shift is set correctly, first time of asking.
So it seems there is a predictable yet undesirable behaviour when using analog scan - if the instrument is in 1st mag range then no shift is set; if already in the 2nd mag range the shift is applied. Interestingly however, if the instrument is in scanning 'off' mode, to start with, non of this happens!
So, I ask: is this behaviour consistent on other SX100 instruments? Perhaps this is because of the order you are sending commands?
I know these are little, mundane things, that don't apply to most people in most cases, but they can still catch people out, especially at 2100 when you just want to leave!!!
Cheers, and thanks for all the hard work.
Gareth