In an earlier blog about the three Adimec 25 Megapixel offerings there is a small mistake. The wrong Quantum Efficiency (QE) curve was used which suggested there is a difference in QE between the VITA and PYTHON sensor.
Luckily we have some alert readers who notified us about this mistake and this allows us to correct for it in this blog. The QE for the VITA sensor and the PYTHON sensor is more or less equal, as shown in the figure below.
The VITA sensor is present in our S-25A30 camera link camera and in our S-25A70 CoaXPress camera. The PYTHON is present in our S-25A80 camera.
Interesting to note is that for the PYTHON sensor we also have a camera available which has the NIR variant of this sensor. The QE of this NIR variant is added in the graph below. This NIR variant does have a higher QE in the NIR region compared to both the normal PYTHON and the VITA. This NIR camera has a CoaXPress interface as well.
Can someone explain me why the QE curve has that irregular shape between 500 nm and 800 nm?
Hi Peter,
Thanks for your question.
It is true that the QE shows some oscillatory behavior over wavelength.
A CMOS sensor has a complex structure of thin layers in the optical path. This complex structure causes interference effects in the quantum efficiency over wavelength.
A CCD would have much less of these interference effects.
For CMOS there might also be a difference between front side illuminated (FSI) and back side illuminated (BSI) in how pronounced the effects are.
I hope this answers your question.