Pentax 645Z Review
September 29, 2014
- 51.4-million-pixel CMOS sensor with no AA filter
- Excellent value, used manual-focus 645 lenses available
- Cheaper than the medium-format competition
- Weighs 1,470g
- AF could be a little faster
Price as Reviewed:£6,800.00
Its resolution is staggering, but there is much more to the 51.4-million-pixel Pentax 645Z medium-format digital camera. Richard Sibley finds out what it is like to use in our Pentax 645Z review
Pentax 645Z Review – Introduction
Usually the preserve of the professional studio photographer, Pentax has been trying to tempt enthusiast photographers with a medium-format digital camera since the launch of the Pentax 645D in March 2010.
The format certainly offers some advantages, especially for those who require a shallow depth of field and the ability to record the finest of details.
Obviously, at almost £6,800 body only, the price of the new Pentax 645Z may still be prohibitive to most photographers, but it is still certainly far cheaper than other medium-format options from the likes of Hasselblad or Phase One. And, of course, renting the Pentax 645Z is another option for those who want to use it for a particular project.
The real questions for the DSLR shooter thinking of using the Pentax 645Z are, how easy is it to make the switch and how good is the 51.4-million-pixel sensor?
Pentax 645Z Review – Features
Although the 51.4-million-pixel sensor may be new, its dimensions aren’t, with the sensor being the same 44 x 33mm size as the original unit in the 645D. This means that the Pentax 645 cameras have a 35mm equivalent focal length multiplier of 0.8x, so a 100mm lens is equivalent to an 80mm lens on a 35mm full-frame camera.
Perhaps more important than the comparatively slight increase in resolution from the 40-million-pixel sensor in the 645D to the 51.4-million-pixel sensor in the 645Z, is a switch in the technologies. The original 645D used a CCD sensor, whereas the new 645Z uses a CMOS sensor.
While CCD sensors usually produce better images at low sensitivities than their CMOS counterparts, improvements in CMOS technology mean that the difference is becoming negligible, and offset by the other advantages of CMOS sensors. One of the advantages is an increase in sensitivity from ISO 100-1600 on the 645D to ISO 100-204,800 on the 645Z.
This big increase makes the 645Z much more versatile compared to its predecessor, opening up other opportunities aside from studio and landscape photography.
The CMOS sensor also allows for video capture at a full HD resolution of 1920 x 1080 pixels, at either 60i, 30p or 24p frames per second.
The shallow depth of field that is afforded by the larger sensor may make the 645Z an intriguing prospect for videographers, especially as there are many older manual-focus Pentax 645 mount lenses from the digital camera’s older film siblings. If you hunt around for these lenses, it is possible to find a bargain or two.
Like the Pentax K-3, the 645Z has no AA filter, meaning that the maximum resolution can be captured from the 51.4-million-pixel sensor. The high resolution means that moiré patterning shouldn’t be an issue; however, if it does start to appear in images, the award-winning AA filter simulator feature can be used.
The Pentax 645Z uses a 3.2in, 1.04-million-dot LCD screen. Usefully, the screen is tiltable, which I found partnered the live view really well, particularly for landscape images.
In comparison with a 35mm-frame camera, the optical viewfinder has a magnification of 0.85x when used with the 75mm lens. The finder offers a 98% field of view.
The 645Z is compatible with Flucards. These SD-sized cards offer Wi-Fi connectivity, and enable not only image transfer to a smartphone or tablet, but also remote camera control.
- Sensor: 51.4-million-pixel, 44 x 33mm CMOS sensor
- Output size: 8256 x 6192 pixels
- Focal length mag: 0.8x
- Lens mount: Pentax 645AF2
- Shutter speeds: 30-1/4000
- ISO: 100-204,800
- Metering system: 86,000-pixel RGB sensor
- Exposure compensation: +/-5EV in 1/3 EV steps
- Drive mode: 3fps
- LCD: Tiltable 3.2in, 1/04-million dots
- Viewfinder: Keplerian telescopic trapezoid prism finder
- AF points: 27 (25 cross-type)
- Video: 1920 x 1080 pixels at 60i/50i/30p/25p/24p
- External mic: Yes
- Memory card: SD/SDHC/SDXC or Flucards
- Power: Rechargeable Lithium-ion battery D-LI90
- Dimensions: 117 x 156 x 123mm
- Weight: 1,470g