I don't think that's correct old chap.
With Toupview and an attached Toupcam the method is as follows,
To Calibrate an objective:-
1) Attach the Toupcam and 'get the live image up on screen' within Tview.
2) Place a calibration slide under your 'scope and focus on it in Tview - this gives
a (focused) set of lines that are a known distance apart and are therefore your reference
for calibration.
3) Set the image view in Tview to 100% (this is
VITAL) then select the calibration
option - this brings up a line that may be stretched to exactly from one of the
calibration lines to another - this will of course be a known distance.
4) Set the line to exactly from one line to another and tell Tview the actual
length of the line - e.g. 12 lines of a 0.05mm (between lines) calibration scale will be a line of
actual length of 0.6mm or 600µ...
5) Enter a new name for this calibration (a separate calibration is needed for each objective and
camera combination used) for example if you're calibrating your x4 objective then you may save it
as 'myx4'..
6) You are now ready to measure with the x4 (i.e. the just calibrated) objective.
To measure using the x4 objective:-
1) Place your slide under your 'scope and focus (in Tview) as usual (with the x4 objective in this case).
The picture view size no longer needs to be at 100% (this is only necessary during calibration) - view at
whatever size you like.
2) Select your new (x4) setting in the drop-down that started with 'NA' displayed - so select the setting
(i.e. the new calibration) you previously called 'myx4'. Use the measurement tool (I usually use the
'horizontal line' or the 'arbitrary line' tool to draw a line on the live-vies image between two points to measure,
e.g. across a cell or perhaps along a leg etc...
3) The distance will appear next to the line - choose whatever unit you prefer (any unit will work from the calibration,
it doesn't need to be the same unit used when calibrating, each unit is just another way to express the same value
(distance) after all.
At this point you have the live-view with a measurement layer superimposed upon it.
To save this image (i.e. take the picture) you can now use F8 to save with separate layers for the measurement line
and the image itself.
If you save this now as a TIFF file as a consequence of the F8 press, the measurement and image layers will remain discreet - i.e. not 'flattened' to use a PSE term.
Now, using F2 will save as a jpg and the layers will merge (flatten) into a single image - the finished article you may say..
There's more....... Tview is able to measure images from other cameras too, even though it can't connect to them as it
does to a Toupcam - the image itself from for example my EOS 1200D may still be measured using Tview!
I may make a short video of this process as the above is a little long-winded and may even have a mistake - I've just typed it straight in from memory and haven't checked the procedure over yet - but I think it's correct - please let me kknow if you need clarification or correction and I'll make a 'proper job' of the instructions. I hope this helps a bit.