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Resolution Chart Comparison (JPEG)

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 (when talking about line pairs 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.

Note that while we usually compare both JPEG and Raw on the same page, here we've put just JPEG from both the K-5 II and K-5 IIS to compare the results with and without a low-pass filter. Look to the next page to compare Raw images from both cameras.

JPEG

K-5 II (4928 x 3264) 9.1MB K-5 IIS (4928 x 3264) 8.7MB

Vertical resolution

K-5 II
K-5 IIS

Horizontal resolution

K-5 II K-5 IIS

To find the two cameras' optimal resolutions, we shot with the 50mm F2.8 Macro lens and judged F5.6 to be sharper than other settings. Compared JPEG to JPEG, there's a slight difference between the K-5 II and K-5 IIS, with the former offering more apparent resolution across the range of possible interpretations - though we'd call maximum 'real' resolution at about 2100LPH - but the K-5 IIS delivers crisper results, resolving nearer to 2200LPH . Color error or moiré appear in the K-5 IIS's rendering more than the K-5 II, however, which is an important factor to consider, as it joins the extra sharpness along the way to 1900LPH, while the low-pass filter of the K-5 II avoids the effect by 2100 lines.

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Comments

Total comments: 6
Lucas1981r
By Lucas1981r (3 weeks ago)

Ok - K-5II have better AF and... and... but why only 80%/ s-81%? If old version K-5 have 83%?
and Nikon D7100 have 85% - but everybody knows - who used this dslr's that Pentax is better...??

1 upvote
Derma pro
By Derma pro (2 weeks ago)

I heard and read alot about this pentax. and I believe it is a very good camera. what I know is that pentax k-5II is better regarding the details of the photo. and D7100 is better regarding the colors and the auto white balance. do you think the pentax is better is other situations?

0 upvotes
KZMike
By KZMike (3 weeks ago)

The S has everything I need [Time Lapse too], EXCEPT a LCD that moves/articulates. . . ughhh!!!!

0 upvotes
Kfrog
By Kfrog (2 months ago)

The auto focus in low light is better and the redesign of the rear LCD has been change for better viewing in bright light. Not much else as far as I know. I purchased the K-5II because I often take photos in low light situations and can use all the help I can get!

0 upvotes
dousanmiaography
By dousanmiaography (2 months ago)

Seriously, what is the difference between K-5 and K-5II? Every single specification are the same.

0 upvotes
Rutterbutter
By Rutterbutter (1 month ago)

The removal of an anti-aliasing filter. this allows for sharper images in the II but sacrifices the tendency to produce moire.

0 upvotes
Total comments: 6