Rainbow Nameplate Jupiter 8

[kansalliskala]

No I didn't color it myself, that was combined effort of my Kodak and Sigma 50/2.8 AF Macro (which is otherwise very very good lens).

Does someone know what the proper name of this phenomenon is?
(Ok - "Kodak" is not the right answer )

EDIT: I changed the title, don't want anyone to get offended .. this started as joke but came to be a good thread anyways. This is why I like this forum.

[Spotmatic]

It's lateral chromatic aberration, seen around high-contrast transitions.

[kansalliskala]

It is in the center of the picture ..

Is this the same phenomenon? I saw once the name of it but can't find it again:

[Spotmatic]

Yes, it is the same. A good read about the subject: http://toothwalker.org/optics/chromatic.html

[no-X]

Spotmatic: In this situation I can't agree fully. Maybe there is some chromatic aberration, but 90% of this "effect" is created by the Kodak body.

Let me explain:

Kodak (and almost all digital cameras) use bayer sensor, which captures only one color channel per pixel (red or blue or green). If the sensor captures per-pixel details and esp. details in black&white, problem is on the way. Originally color-neutral (BW) data is captured as chromatic data (as red, or blue, or green).

Canon, Nikon, Pentax, Olympus, Sony, Panasonic... use optical "correction" - so called low pass filter, which is placed in front of the bayer sensor (the low-pass filter blurs per-pixel data to prevent capturing of per-pixel details, which would change into color mess - in camera processor then applies some sharpening to make the image look sharp).

Leica doesn't use low-pass filter - they use special software processing to avoid this problem.

Kodak doesn't use low-pass filter, but (at least their older camera models) don't use any software correction.

Here is 1:1 example of this Kodak phenomenon on black/white situation:




Some time ago I posted here this simulated example:

Example of bayer-based camera system without low-pass filter:



A: real image
B: image taken by bayer sensor (what can the camera "see")
C: image processed (debayering) by the camera - quite sharp, but color artifacts are present

Example of bayer-based camera system with low-pass filter:



A: real image
B: what does the low-pass filter do (fine details are removed as prevention of artifacting)
C: image taken by bayer sensor (what can the camera "see")
D: image processed by the camera (debayering)
E: final processing (sharpening)

image lost some detail, but artifacts aren't there

[kansalliskala]

Thank you No-X, this is actually very good news for me!

Now I just need to hack some software ..
It is way easier than hacking the sensor.

[kansalliskala]

[Spotmatic]

Excellent work, no-X! Thanks for explaining it so thoroughly.

[LucisPictor]

[kansalliskala]

Actually I already downloaded DCRaw source. Program is not very difficult .. but then I should understand the algorithm also ..

Or just change something and see if I get b&w or some caleidoscopic effect.