A Viewfinder Darkly

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Pentax K-1 a  full-frame DSLR at last

March 9 2016

by Philip Northeast

The Pentax K-1 is DSLR with a digital sensor the same size as the old 35mm film. The new sensor is probably the same Sony  unit that is used in  Nikon’s D800 series cameras.

Pentax has been promising their  full-frame DSLR  for several years, but the details from Pentax suggest the  wait might have been worthwhile.  Part of the delay is probably due  to Nikon getting preferential treatment from the sensor manufacturers, Sony. This is a familiar scenario with Pentax playing second fiddle to Nikon, who buy many more sensors from Sony  than Pentax.

Even though they may share hardware, each camera company have their own processing methods in their cameras.  Pentax has a history of  achieving very good skin tones, dynamic range, and noise performance with their systems.   It could be that Pentax used this  extra time  to develop their processing algorithms. In the K-1 this is the PRIME IV imaging engine, these interpret  the electrical signals from the digital sensor to produce the image file.

Pentax K-1 front view

Pentax K-1 front view

Another advantage is Pentax’s pixel shift technology that combines four images of the same scene with the sensor moved by one pixel using the shake reduction mechanism. This compensates for the normal Bayer system where four photocells with different colour filters are used to create one pixel in the image. The slight physical offset for the four cells limits the ultimate resolution of the  sensor. Shifting the sensor reduces this problem to deliver greater resolution and truer colours. Similar technology is found in high-end medium format cameras, but Pentax has pioneered its introduction to DSLRS.

The new to Pentax full frame sensor

The new to Pentax full frame sensor

The Sony and Nikon cameras using this full frame digital sensor are highly rated for image quality by independent  tester DxOMark.  The DxOMark tests will reveal how the K-1 stacks up against the others, but their rankings suggest  the Pentax K-1 is one of best DSLRs for image quality.

Any differences will be subtle and I don’t expect Pentax engineers will have  extracted and significant performance gains from the sensor compared to their Sony and Nikon counterparts.

The Pentax K-1 has a moveable rear screen

The Pentax K-1 has a moveable rear screen

The K-1 is now  Pentax’s  top performing DSLR and the main market is Pentax users.  The immediate aim is to keep their existing high-end DSLR photographers in the fold rather than entice high-end photographers with Canon or Nikon systems. The lens systems are  the key to DSLRs, the camera body is only part of the story. The interchangeable lenses  form a significant part of the total investment in photographic equipment.   Camera manufacturers each have their own unique  lens mounting system, so it is  hard to share lenses between different makes  of camera.


One of the attractions of Pentax DSLRs is they support photographers with older lenses, so any lens for a Pentax K mount will fit on their modern DSLRs.   This is good news because the Pentax policy had been to concentrate on DSLRs with the smaller APS-C sized sensors. Their new lenses are designed to suit the smaller image area. This might have caused problems, but many Pentax  photographers have older lenses from the film era that utilise all of the K-1’s sensor. Then there are some current Pentax lenses that are updates of older full frame designs, so they benefit from new technology and are suitable for the K-1.

Some of my full-frame lenses for Pentax K Mount

Some of my full-frame lenses for Pentax K Mount

This evolution of some lens is why Pentax say some of the DA lenses intended for the smaller APS-C  image circle will provide an image circle large enough for the full-frame K1. Doing a rough test with my Pentax lenses mounted on an old film camera body, the image visible in the viewfinder were encouraging. Some definitely  are suitable for full-frame, while others produce an APS-C size image circle with distinct vignetting, or black areas, in the corners of the full frame view. So the worst case scenario for a new Pentax DA lens is that it can only produce an APS-C size image on the K-1 after the vignetting is cropped out. You can get the camera to do that, or leave it until post processing, whatever suits your workflow. The cropped image should come out at about 24 megapixels, not exactly a disaster.

Another source of high-quality full-frame lenses is Pentax’s medium format items from the 645 series cameras. Pentax has introduced an adaptor that allows these lenses to fit on the  K-1. This makes the K-1 a good second camera for photographers with a Pentax 645  medium format system.

New lenses 

Because the K-1 took so long from concept to realisation Pentax quietly started designing their new lenses to work with full-frame DSLRs.  To reinforce the point Pentax also announced  two new full-frame weather resistant lenses  The compact general purpose FA 28-105mm zoom is under $US500 from Adorama making the whole package still cheaper than buying only a Nikon D810 body.

Then there is a new premium quality wide angle zoom, the D FA 15-30mm F2.8ED SDM WR at   around $US1449.95  from Adorama.


Pentax K-1 offers Wi-Fi LAN connection to mobile devices and tablet computers allowing instant photo sharing and remote camera control through the Image Sync app.


The K-1 comes with a built-in GPS unit so location data can be included in the EXIF data included in each image file. This is useful for landscape and travel photographs where it is hard to determine the exact location of the photo. Photo processing apps such as Adobe’s Lightroom can sort and select images based on its location from the GPS data, and show the location on a map.

The photographer's view of the Pentax K-1

The photographer’s view of the Pentax K-1


The Pentax K-1  promises to be a high-resolution DSLR that closes the gap to high-end medium format digital cameras at a fraction of the cost.  Considering  the relatively low price of the K-1 compared to its competitors the new Pentax K-1 is attractive to new photographers who want to upgrade to a high-resolution DSLR.

Pentax K-1 DSLR Camera Body available for pre-order from Adorama for  $US1799.95


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