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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. Nyquist is indicated in these crops with a red line.

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 (4608 x 3072) 3.7MB RAW (4608 x 3072) 3.7MB

Vertical resolution

JPEG
RAW

Horizontal resolution

JPEG RAW

In stereotypical Nikon fashion, the D3100's conservatively-sharpened JPEGs show slightly lower resolution than can be extracted from RAW. They struggle to render the nine lines of our resolution chart in well-separated fashion much beyond 2200 LPH, as opposed to the 2400 LPH or better visible in the raw conversion. The raw conversion also shows distinct line patterns beyond Nyquist; this is false detail, which can often enhance the impression of resolution in 'real' images. The penalty for this, though, is a bit of additional colour moire.

Overall what this means is that the D3100 lags slightly behind other recent 14Mp APS-C cameras (such as the Sony NEX-5) in terms of JPEG resolution, but if you switch to raw it can certainly hold its own.

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Comments

Total comments: 3
sarath cp
By sarath cp (1 month ago)

nikon d3100 is an intermediate dslr? right? i saw a post about guides for buying a dslr on www.know4u.com
actually they says that there is too much to investigate before buying one... is that true always..? the link is http://know4u.com/dslr%20photography/How%20to%20Choose%20a%20DSLR%20Camera/How%20to%20Choose%20a%20DSLR%20Camera.html

0 upvotes
whodat101
By whodat101 (5 months ago)

Looking at the comparison, it appears to my novice mind that the d3100 has in most areas slightly better specs than the d5000. Since I am looking at both of these cameras, would appreciate comments. The 3100 is on sale at the local camera shop; the 5000 is available on Craiglist at a considerably lower price, but is of course used.

Also; packed away I have two nikon entry level cameras from the early 1980's with quite a few E series lenses. The E series lens was standard on the two cameras. Will these work on the 3100 and 5000, and if so, are there problems in compatibility such as auto-focus, etc.

0 upvotes
Flight815
By Flight815 (3 months ago)

D3100 is a great camera. i bought another one recently new from Target..dont need anything newer or more $$$ this thing is just perfect.I think it only auto focuses with Nikon AF-S..you'll have to read up on 3rd party lenses for af.

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Total comments: 3