D800 Resolution Chart Comparison
(JPEG and Raw)
Images on this page are of our standard resolution chart which provides for measurement of resolution up to 4000 LPH (Lines Per Picture Height). A value of 20 equates to 2000 lines per picture height. For each camera we use the relevant prime lens (the same one we use for all the other tests in a particular review). The chart is shot at a full range of apertures and the sharpest image selected. Studio light, cameras set to aperture priority (optimum aperture selected), image parameters default. Exposure compensation set to deliver approximately 80% luminance in the white areas.
What we want to show here is how well the camera is able to resolve the detail in our standard test chart compared to the theoretical maximum resolution of the sensor, which for the charts we shoot is easy to work out - it's simply the number of vertical pixels (the chart shows the number of single lines per picture height, the theoretical limit is 1 line per pixel). Beyond this limit (which when talking about line pairs is usually referred to as the Nyquist frequency) the sensor cannot faithfully record image detail and aliasing occurs.
This limit is rarely attained, because the majority of sensors are fitted with anti-aliasing filters. Anti-aliasing filters are designed to reduce unpleasant moiré effects, but in doing so, they also reduce resolution (the relative strength and quality of these filters varies from camera to camera). In theory though, a sensor without an AA filter, when coupled with a 'perfect' lens, will deliver resolution equal to its Nyquist limit. Therefore, even though it may be effectively unattainable with normal equipment in normal shooting situations, an understanding of a sensor's theoretical limit provides a useful benchmark for best possible performance.
On this page we're looking at both JPEG and Raw resolution. For a (more) level playing field we convert the latter using Adobe Camera Raw. Because Adobe Camera Raw applies different levels of sharpening to different cameras (this confirmed) we use the following workflow for these conversions:
- Load raw file into Adobe Camera Raw (Auto mode disabled)
- Set Sharpness to 0 (all other settings default)
- Open file to Photoshop
- Apply a Unsharp mask tuned to the camera, usually 100%, Radius 0.6, Threshold 0
- Save as a TIFF (for cropping) and as a JPEG quality 11 for download
|JPEG (7360 x 4912)||Raw (7360 x 4912)|
In the samples below, we typically include a Nyquist 'marker' indicating the theoretical limit of a given sensor's resolving capability. The D800, however has a theoretical maximum of 4,912 lines per picture height while our current chart 'only' measures up to 4,000 lines per picture height. Note that the crops below are too tight to include the lines per picture height figures on the chart, so we have overlaid the numbers for convenience.
|JPEG 100% crop|
|Raw 100% crop|
|JPEG 100% crop||Raw 100% crop|
With its 36MP sensor, the D800 is among the highest resolution cameras we've put before our test chart. And as you'd expect,t its performance here puts it at the head of the class among its DSLR peers.
We should note, however, that we had to work quite hard to get this amount of resolution. We used flash to eliminate any risk of blurring due to vibration, we focus-bracketed in extremely fine increments, and we used an excellent lens (the Nikkor AF-S 50mm f/1.4 G) at an aperture optimal for central sharpness of F4.5. Even with the inevitable softening that results from using an anti-aliasing filter, this methodology allowed us to tease resolution out of the camera as high as 3200 LPH, which, for practical purposes is about the maximum we'd have expected to see.
The fact that we had to go to these lengths, though, simply reinforces the fact that the D800 really does demand a 'medium-format mindset' to get the best results.