6. One side of the image is out of
focus.
II. Mechanical Section:
1.The coarse focus knob is hard
to turn.
2.The focus is unstable.
III. Electric section
1. The LED doesn't turn on.
2. The brightness is not enough
3. The light blinks
IV. Viewing tube assembly
3. The field of view of the two
eyes is different
V. Microphotography and video
1. The image is unfocused
2. The edge of the image is
unfocussed
3. Bright patches appear on the
image
The nosepiece is not in the
center of the light path
The specimen is out of place
(tilted)
The optical performance of
the sample cover glass is
poor
The tension adjustment col-
lar is too tight
The tension adjustment col-
lar is too loose
No power supply
The brightness adjustment
is low
The power cord is poorly
connected
The interpupillar distance is
not correct
The dioptric correction is not
right
The viewing technique is not
correct, and the operator is
straining the eyesight
Incorrect focussing
To some degree, it is inher-
ent to the nature of achro-
matic objectives
Stray light is entering the
microscope through the
eyepieces and through the
camera viewfinder
15
Turn the nosepiece to a click stop
Place the specimen flat on the stage.
Use a cover glass of better quality
Loosen the tension adjustment collar
Tighten the tension adjustment collar
Check the power cord connection
Adjust the brightness
Check the power cord
Adjust the interpupillar distance
Adjust the dioptric correction
When look into the objective, do not
stare at the specimen but look at the
whole field of view. Periodically, move
the eyes away to look at a distant ob-
ject, then back into the objective
Adjusting the focus system as in the
present manual
The problem can be minimized by a
correct setting of the aperture dia-
phragm
Cover the eyepieces and the viewfind-
er with a dark cloth