|Introduction | Anti-aliasing filter: How useful is it? | Nikon D7100 results: ultra high performance | Best prime lenses for the D7100 | Best Zoom models for the D7100 | A decade of evolution in sensor design and image quality|
The resolution of a camera describes the ability of a sensor and lens to resolve fine details but the role of the OLPF is to reduce aliasing by lowering the sampling frequency of the sensor. The trade off is a reduction in sharpness.
Manufacturers have for a long time specified different ‘strengths’ of OLPF in the sensor’s filter-pack from model to model but it’s only recently we, as consumers, have been offered the choice in some models, such as the 36.3Mpix Nikon D800 and D800E. Now we’re only just beginning to see models emerge with no anti-aliasing filter.
The high pixel count of the Nikon D7100 along with the complete removal of the OLPF promises optimal sharpness and resolution. However, it’s worth bearing in mind that some aliasing or color artefacting may be present in both stills and, more importantly, video (as it’s far more difficult to contend with). As far as stills are concerned, moiré removal is included in most good editing apps and is often quite simple to deal with.
While the effects can occasionally be seen with man-made structures, particularly cityscapes for instance, regularly repeating structures aren’t often found in nature. Sometimes the patterning effect of moiré can be seen with bird feathers but it occurs only when the detail, or in fact spatial frequency, exceeds the resolution of the lens and sensor.
Some low cost, lower-performing super zooms will never achieve a high enough resolution for images to exhibit moire, but on the other hand should also allow the lens to achieve its highest potential sharpness.
There are a few other potential performance issues regarding higher resolution capture to be aware of. With good quality lenses, of course, very high sharpness levels are possible but both discipline and good photographic technique are required to achieve decent results. Focus accuracy is crucial of course, while even the slightest camera shake, can lead to substantial image blurring.
Please refer to our glossary for the definitions of sharpness and resolution.