The operation of AF can be tested by taking images of objects at different distances. Good distances are 20
cm, 60 cm and infinity (>3 m). Any LED or xenon flashes should not be used while taking the images.
The taken images should be analysed on PC screen at 100% scaling simultaneously with a reference image.
Pay attention to the computer display settings; at least 65000 colors (16 bit) have to be used. 256 (8-bit)
color setting is not sufficient; true color (24 bit, 16 million colors) or 32 bit (full color) setting is recommended.
If the differences are noticeable at a glance and also if the one under investigation is significantly inferior,
the module might have a faulty lens. In this case, the module should be changed. Always re-check the
resolution after changing the camera module. If a different module produces a clearly noticeable quality gap,
the fault is probably in the camera window. Check the window by looking carefully through it when replacing
the module. As references Figure "Good image taken indoors" and Figure "Good image taken outdoors" can
be used. Another possibility is to use a service point comparison phone, if available.
Effects of dirty or defective camera lens protection window
The following series of images demonstrates the effects of fingerprints on the camera protection window.
Note:
The effects of any dirt in images can vary very much; it may be difficult to judge if the window
has been dirty when some image has been taken or if something else has been wrong. That is why
the cleanness of the protection window should always be checked and the window should be wiped
clean with a suitable cloth.
Figure 53 Image taken with clear protection window
Figure 54 Image taken with greasy protection window
RM-701
Camera Module Troubleshooting
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COMPANY CONFIDENTIAL
Issue 1
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