Pentax K-1 Review
Advantages of Full Frame
As the first full-frame DSLR from Pentax, the K-1 opens up new opportunities for current users of the Pentax K-mount system or other crop systems.
The primary advantage of the full-frame format is superior image quality. Compared to an APS-C body such as the Pentax K-3 or K-5, the K-1 boasts more than twice the sensor area, at roughly 864 square millimeters, compared to 384.
Without getting overly technical, the larger sensor size enables higher resolutions, improved dynamic range, more accurate colors, and better performance in low light or at high sensitivity settings. This can primarily be attributed to larger pixel pitch, as bigger photo sites are able to pick up more light.
Secondary advantages of the full frame format include a more sizable optical viewfinder, shallower depth of field, less diffraction, and easier access to lenses with wider angles of view.
Here's a simple example in which the Pentax K-1 pulls ahead of the K-3. This photo was taken at ISO 25,600 and scaled from full resolution:
Let's also consider a typical daytime landscape scene:
Test scene: Pentax K-1 @ 30mm, K-3 @ 20mm w/ D FA 15-30mm F2.8 @ F8
Even in this simple test scene, we observe better color accuracy and detail from the K-1 over the K-3, especially when we turned up the ISO. The comparative photos below were all developed from RAW using Adobe Camera Raw. Files from the K-3 have been up-sampled to match the resolution of the K-1. The same shutter speed and aperture was selected on both cameras.
Of course, everything comes with its trade-offs: full-frame lenses are often bigger, heavier, and more expensive than crop lenses, as are the cameras. This is especially true of telephoto lenses, and thus many photographers prefer APS-C for their telephoto needs.
Whether or not the full-frame format is right for you will depend on your budget and your needs with respect to image quality. Regardless, one thing is for sure: you won't find a K-mount DSLR in the current lineup with better overall performance than the K-1. And that's just the sensor speaking; there's much, much more to the K-1.