Cameras lacking anti-aliasing filters tend to suffer from color aliasing and moiré. Usually this is not an issue, but it can all but ruin some images. But there is a workaround that is easy and practical for many purposes, with a “balancing point” of best results (sharpness and contrast versus mitigating aliasing).
Effects of Diffraction Blur on Color Aliasing (with Leica S2)
The example presented is with the Leica S2, but it applies to any camera with any size sensor. The discussion includes a full size image as well as three large apertures series from f/2.8 - f/11 that illustrate the effects.
The Nikon D810 and D800E have no anti-aliasing filter; the new Canon 5DS has such a filter, but the 5DS R does not. Similar considerations apply to other models and brands.