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Lensrentals | all galleries >> photogeek_contest >> distortion_correction > OscilloscopeCorrected.jpg
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07-Nov-2013 Tom Brown


Nikon D800
1/13s f/2.0 at 35.0mm iso100 full exif

other sizes: small medium large original
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Lasse 25-Nov-2013 12:39
What a pity.
Coastal summer lab, eh? Do you have a coastal optics 60mm UV-VIS-IR, too? I'm surrounded by coasts but I don't. :)
Guest 23-Nov-2013 20:00
I apologize - I left my Frequenzrückbiegezange in Spain in my coastal summer laboratory, and my personal jet courier was in Bora Bora retrieving my macro-acoustic collimator that was I had planned to use for a different contest.
Lasse 21-Nov-2013 20:27
Regarding the Sine Wave Distortion: Your correction approach is Digital Signal Processing, and every audiophile knows that this is detrimental to the sound quality! Better use a Frequenzrückbiegezange ;).

Nice work though and Tektronix is very geekish. I only own an old analog Hameg...
Lensrentals15-Nov-2013 14:31
Description: I needed a screen shot of the oscilloscope of the bus signal from a high speed satellite communications FPGA. Unfortunately, each time I used the scope's screen capture function I kept getting a distorted signal. Fortunately, I had my D800 and 35mm f/2 handy, so I took a screen shot with the camera and corrected the following:

Barrel Distortion: inherent in the lens, lightroom
Vignetting: inherent in the lens, lightroom
Perspective: I couldn't get the camera squared up with the scope, but now the grid lines are perpendicular, vertical and horizontal, Photoshop
Skew: I didn't hold the camera level (even though it was on a tripod and the D800 has a level), so I rotated it .2 degrees.
Chromatic aberration: I wanted to show the piece of tin I received as a souvenir from the hat of nice man I met in the hills of the Nevada desert somewhere in his underground compound, but it kept giving off this purple glow, so I used the chromatic aberration slider in lightroom. This helped clear up some of the bright border pixels from the scope, too.
Corner Sharpness: shot at f/2 - a smart sharpen to remove Gaussian blur at ~10 pixels and 90% helped sharpen those corners up quite a bit.
Sine Wave Distortion: The replace color and clone tool were great for this, so now I can go present the data I collected in it's true original format.

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