Nikon cameras do incredible job with moire effect even that nikon cameras do not have anti aliasing filter.And i didn't find moire in any situation with my Nikon d7100

  • Maybe you didn't look close enough, because there is some according to DPReview – xenoid Oct 28 '18 at 9:58

Moire is one form of "aliasing", which is false detail artifacts created by digital sampling at lower resolution than is necessary to accurately and adequately reproduce the smallest level of detail present.

Better lenses have provided a bit finer image detail than the past sensor sampling could resolve accurately, causing this false aliasing (including moire), so anti-aliasing filters were put on the sensors to blur away the smallest detail, to prevent the aliasing. Physics includes the Nyquist Theorem, which says to eliminate aliasing, the digital sampling resolution must be at least twice higher than the data resolution

But sensors have improved (noise has improved) to allow tiny pixels at very high resolution today, providing sufficient sampling resolution to usually eliminate most aliasing without the filter, including most moire.

That anti-moire tool is the higher sensor resolution, actually sufficient now, without the anti-aliasing filter previously used. Probably not without exception, but the general case is very good today.

So even if we will resample the image to a small 600x400 pixel size later, the greater 6000x4000 sensor size already provided much benefit to reduce aliasing (which includes moire).

So our large sensors are not excessive resolution today, today they have finally become nearly adequate. :) Excessive size for our typical usage perhaps, but not excessive to accurately reproduce the lens image.

  • Well stated and I see this in images from my 5DsR v 1DsII. The former, without anti-alias filters has produced less aliasing artifacts than the latter which has a filter. Diffraction, lens imperfection, and slight camera shake reduces, on average aliasing because the sensor pixxels are much closer spaced. – doug Oct 28 '18 at 16:49

In general, it is not possible to reliably remove moire once it has been captured by the sensor. That's why the correct way to handle the problem is the blurring filter placed before the sensor.

In the real life, however, high megapixel cameras can often get rid of the filter because the image is not going to be perfectly sharp anyway. The "technology" here is imperfect lens and diffraction effects limiting the image resolution.

  • There might be an adequately reliable solution in just heuristically detecting moire and retouching it out, though :) – rackandboneman Oct 28 '18 at 22:06

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