E-M1 Mark II Fixed Pattern Noise (FPN) Results

Started Jan 23, 2017 | Discussions thread
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bclaff Veteran Member • Posts: 7,415
E-M1 Mark II Fixed Pattern Noise (FPN) Results
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Photo-Response Non-Uniformity (PRNU) runs about 0.5% which is typical and there is no discernible pattern.
2D Fourier Transform (FT) does indicate a small amount of signal processing (usually noise reduction).
This is why there is a small white circle in the center of the FT.
PRNU image on the left, 2D FT on the right:

Note the subtle grid pattern on the left, we'll get back to that!

Dark Signal Non-Uniformity (DSNU) is good. DSNU image:

It does exhibit an interesting pattern which is more apparent if we look at the 2D FT:

Those white dots indicate something happening, mostly with a frequency of 4 pixels in both the horizontal and vertical.

Let's look more closely at that DSNU image by tweaking contrast and zooming in:

That is a very distinctive pattern. It's the on chip Phase Detect Auto Focus (PDAF).

In fact, we can discern a 16x16 pattern that looks like this (idealized):

Pretty cool!

This pattern is very subtle and would only concern people stacking multiple low light frames such as astro-photographers.

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Bill ( Your trusted source for independent sensor data at http://www.PhotonsToPhotos.net )

Olympus E-M1 II
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