Studio Comparison

Our latest test scene is designed to simulate both daylight and low-light shooting. Pressing the 'lighting' buttons at the top of the widget allows you to switch between the two. The daylight scene is shot with manually set white balance aimed at achieving neutral grays, but the camera is left in its Auto setting for the low-light tests (except Raw, which is manually corrected during conversion). We also offer three different viewing sizes: 'Full', 'Print', and 'Web', with the latter two offering 'normalized' comparisons to more fairly compare cameras of differing resolutions by ensuring equivalent viewing sizes.

Resolution

The Nikon D5500 carries over the same anti-aliasing (AA) filter-less APS-C sensor found in the D5300. This means it holds up well in terms of resolution compared to its competition. The crucial differences between the three different sensors shown here are resolution and anti-aliasing strength. The Canon Rebel T5i has the lowest resolution and appears to have the strongest AA filter, so the most intricate details of the monotone etching in the studio scene are not necessarily lost, just blurred when compared to the Nikon and the Sony a6000. The advantage is the Canon has virtually no color moiré, while the Nikon and Sony have waves of magenta, cyan, and yellow happening in the higher-frequency details of the etching. The Sony still has an AA filter, albeit a very gentle one. The differences between it and the D5500 are almost none, but this probably has more to do with the lenses than the sensors of these cameras.

The Sony is equipped with one of the sharpest lenses being made, the Zeiss 55mm f/1.8, and the Nikon was shot with the aging Nikkor 50mm f/1.4. We considered replacing our on-brand 50mm primes with the venerable Sigma 50mm Art lens, but ran into some issues.* However, had the Sigma 50 Art been used, the D5500 would have yielded sharper results, possibly on par with the Sony a6000 results here.

Shutter Shock

One issue with using a sensor design without an anti-aliasing filter is the camera's sensitivity to vibrations increases. The AA filter-less Sony a7R is infamous for its "shutter shock" issues that hinder it from getting the most resolution possible in certain circumstances. We found a similar issue with the D5500. We shot our scene with Exposure Delay, and a 2 sec timer triggered via an infrared remote. Focus is set at the beginning and does not change throughout the progression. ISO 200, which was shot at a shutter speed of 1/80s, is already not quite as sharp as ISO 100, shot at 1/40s. Blur gets worse at ISO 400 and 800, which required shutter speeds of 1/160s and 1/320s, respectively, in our studio scene. By ISO 1600, which is shot at 1/640s, the image is back to being as sharp as it should be. This suggests that some sort of vibration, most likely from the shutter since the mirror completes its movement 1 sec before the exposure begins in Exposure Delay mode, is happening inside the camera that either (1) lasts short enough to not affect slightly longer exposures (1/40 sec for ISO 100), or (2) short exposures 'freeze' any motion from vibration or shake (1/640 for ISO 1600). The vibration, however, becomes a significant fraction of the exposure for shutter speeds between 1/80 and 1/320 and, so, causes visible blur.

The D5500 is not the first camera we've seen with this issue, as the D5300 also shows a similar progression of critical sharpness. This isn't so serious that it will ruin photographs, but it's something to be aware of with higher resolution cameras. This issue will affect micro-contrast and sharpness in limited situations, and may be exacerbated with long focal lengths. It does not render the camera useless, but in some circumstances it can prohibit you from maximizing the potential of the higher resolution, AA-filterless sensor.

ISO Performance

The Nikon D5500 shows very similar Raw high ISO performance to the D5300, all the way up to ISO 25,600, indicating that the cameras are likely using the same or similar sensor. This is mostly a good thing when it comes to low-light performance, as the D5300 was a top performer that made it outperform cameras like the Sony a6000 and Canon 70D. In fact, the D5500 and D5300 have the least noise compared to their immediate competitors, the Canon Rebel T5i and Sony a6000, at ISO 25,600. We'll take this opportunity to note, however, that there is a new class-leader in terms of high ISO performance amongst APS-C cameras: the Samsung NX1 which, with its highly efficient BSI-CMOS sensor, outperforms every other camera in its class. The NX1 is a camera that will need to be taken very seriously while developing next generation cameras, and does a nice job of showing the benefits of backside-illuminated technology in even larger-sized sensors.

JPEG Processing

Between the D5300 and 5500 there are differences in JPEG processing. Noise reduction appears to be more aggressive at higher ISOs, although chroma noise reduction seems reduced. There's less bleeding of the magenta patch into its black borders, and note how green colors are more preserved at ISO 25,600 in the D5500 shot compared to the D5300 shot. The D5500's more aggressive noise reduction is also evident in the ISO 25,600 Dead Leaves patterns. These patterns also show, in the ISO 100 shots, the impact of Nikon adding 'Clarity' (large radius sharpening) to its JPEG processing engine.


*We originally shot the scene with the Sigma 50mm f/1.4 Art as part of an attempt to introduce that lens as the standard across systems, but we ran into an issue whereby images from the D5500 were coming out noticeably noisier than the D5300. We found that at f/5.6 the native Nikon 50mm was giving consistent exposures shot-to-shot, while the Sigma was underexposing and yielding somewhat inconsistent exposures. Further testing is required and we'll keep looking into it.