The Megapixel Race and Pentax's Potential Full-Frame

When is enough resolution enough?

By PF Staff in Articles and Tips on Sep 3, 2012
The Megapixel Race and Pentax's Potential Full-Frame

Canon and Nikon recently upgraded their top full-frame prosumer models. It is quite interesting to see how the two companies followed quite different paths and it does warrant some discussion and speculation about which specifications Pentax should aim for with their full frame camera (should they decide to build one).

Previous model New model

5D Mark II
21.1 MP
ISO 100 - 6,400
(50 - 25,600 exp.)
3.9 fps

5D Mark III
22.3 MP
ISO 100 - 25,600
(50 - 102,400 exp.)
6 fps


12.1 MP
ISO 200 - 6,400
(100 - 25,600 expanded)
8 fps

36.3 MP
ISO 100 - 6,400
(50 - 25,600 expanded)
4 fps

Nikon came from a dismal 12 MP camera and decided to do a big jump and boost resolution to 36 MP (3510 lines) which approaches medium format resolution (the Pentax 645D is a 40 MP camera) whereas Canon basically stood still with resolution unchanged at (about) 22 MP (2750 lines) and instead used the advances in sensor and processor technology to produce a camera with very low noise and faster burst rate.

Camera specifications are always the result of several trade offs and Canon and Nikon with these new prosumer models decided quite differently on the trade offs:

  • Canon placed emphasis on image quality over resolution and as a bonus got a high burst rate of 6 fps and a top ISO speed of 25,600 (102,400 expanded).
  • Nikon placed emphasis on resolution and accepted noisier images, a low burst rate and a two stop lower max. ISO of 6,400 (25,600 expanded).

Neither did much in the area of weather sealing and in-body shake reduction is not available.

Popular Photography reviewed the two cameras in their July issue. Their reviews are summarized on their web site for those who didn't get the magazine. Their key findings can be summarized as follows:

Canon EOS 5D Mark III Nikon D800


2750 lines 3510 lines

Range of excellent
image quality

ISO 50 - 12,800 ISO 50 - 800
Extremely low noise ISO 50 - 400 ISO 100
Very low noise ISO 800 - 3,200 ISO 50, 200 - 400
Low noise ISO 6,400 - 12,800 ISO 800
Moderate noise ISO 25,600 ISO 3,200
Unacceptable noise Above ISO 25,600 Above ISO 3,200

For low-light shooting the Canon shines with excellent image quality all the way to ISO 12,800 where the Nikon drops below the excellent rating above ISO 800.

But then the Nikon has a staggering resolution of 3510 lines where the Canon tops at 2750 lines.

However, in order to benefit from the D800's high resolution you better use a tripod. Without a tripod camera shake will make it hard to impossible to achieve the resolution that the sensor is capable of delivering. The camera thus lends itself more to landscape (or studio) photography than general purpose photography. It is probably also landscape photographers that would benefit in the most from the D800's high resolution in particular in connection with large prints. For this application high ISO performance is not required and the D800's noise is a non-issue.

Our conclusion is that the 5D mark III and D800 address two different needs. The D800 is for landscape photography and competes with the Pentax 645D, and the 5D Mark III is for general purpose "walk around" and action photography, and for available light work like concerts, wedding and night photography without a tripod, and competes with the APS-C format cameras like the Pentax K-5, Sony NEX-5R and NEX-7, Canon 7D and others.

So where should Pentax place their full frame camera (should one be coming)? We think a 24 MP, weather sealed camera with built-in image stabilization would make the most sense. This would cover travel and action photography also in inclement weather, and landscape photographers who need more resolution (we don't!) could look towards the Pentax 645D which is now coming down in price and benefit from the ability to use the 645 lenses on their K-mount DLSR as well.   We would like to hear your thoughts as well!

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