18
LS720 Microscope Manual 2021
3.
The Max focus time will be set to the default of 15 sec. This can be reduced as performance of the
autofocus is confirmed. The Max focus time should be at least that required for successful
autofocus but optimally only a few seconds longer. Autofocus of 3 seconds should be possible in
flat labware with 2D samples.
4.
Click OK and autofocus will occur. The Focus Z level in Manual XYZ will now be updated to the
new autofocused Z level. The actual time taken to reach autofocus, i.e., the Auto focus time (sec),
will also be shown.
5.
If autofocus did not result in a sharp live image, make sure the Center position transferred was
correct. In general, if autofocus consistently uses the full Max focus time, the range is too great for
the time entered or the time is insufficient. It may be necessary to decrease the Focus range
and/or increase the Max focus time.
6.
Upon successful autofocus, move to other locations distant from the initial location. Click Select
Labware in Manual XYZ and the appropriate Labware Map will open (see Section II.E.3. above).
Select a location and repeat Steps 1-4 above.
7.
Continue to move to other locations far away from the initial ones and repeat autofocus. It may be
necessary to re-enter the Center position and/or adjust the range. To determine the final
parameters, review the upper and lower Z levels obtained and use the approximate mean for the
Center position. For the range, determine the spread between the highest and lowest expected Z
values and make sure the Range contains those values comfortably.
Magnifi-
cation
Numerical
Aperture
Depth of
Field
(µm)
AutoFocus
Minimum Step
Size (µm)
AutoFocus
Maximum
Step Size
(µm)
Minimum
Range
(µm)
Recommended
Z-Slice Step Size
(½ DoF) (µm)
4x
0.10
55.5
20
72
100
27.75
10x
0.25
8.5
8
36
50
4.25
20x
0.40
5.8
2
18
25
2.9
40x
0.65
1.0
1
9
15
0.5
60x
0.85
0.40
0.5
6
10
0.2
100x
0.95
0.19
0.2
4
10
0.11
