Pentax K-7 Digital SLR Review

The Pentax K-7 has been speculated about for a number of weeks thanks to leaked information and spy style blurry photographs on rumour sites.

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Pentax K-7: Specification

• Resolution: 14.6Mp
• Sensor size: 23.4x15.6mm
• Sensor type: CMOS
• Image size: 4672x3104
• Focus system: TTL phase detection
• Focus points: 11
• Crop factor: 1.5x
• Lens mount: Pentax KAF2 bayonet
• File type: RAW, JPEG
• Sensitivity: ISO 100-6400
• Storage: SD, SDHC
• Focus types: Auto single, continuous, manual, point select
• Metering system: TTL open aperture 77 segment metering
• Metering types: Multi, centre-weighted, spot
• Exposure compensation: +/- 5EV
• Shutter speed: 30sec-1/8000sec & bulb
• Frames per second: 5.2fps
• Flash: Built-in (Guide no. 13), external
• Flash metering: P-TTL
• Flash sync speed: 1/180sec
• Image stabilisation: Image sensor shift mechanism (Shake Reduction) max. 4 stops
• Integrated cleaning: Image sensor cleaning function by supersonic vibration
• Live view: Yes
• Viewfinder: Pentaprism type (100% field of view)
• Monitor: 3in TFT LCD, AR coated (921,000dot)
• Interface: USB 2.0
• Power: Li-Ion battery
• Size: 130.5x96.5x72.5mm
• Weight: 670g (excl. battery and card)

Pentax K-7: Features
As a mid-range DSLR, the K-7 sits comfortably above the K20D and shares the same resolution on the sensor meaning that either Pentax have found their limit in terms of resolution or that they're going to launch another model soon with a higher number of pixels.

This is the first venture into what Pentax call the prosumer market. This is a bit of a surprise as it's commonly thought the K20D was at least prosumer but apparently not. "This is somewhere that Pentax haven't been before and we're really excited" said Johnathan Martin, Pentax National Sales Manager.

Capping the resolution at 14.6Mp wouldn't be a bad thing as it would demonstrate evidence of the pixel race beginning to slow. Given that Pentax told ePHOTOzine that they don't think pixels are the be all and end all, would it be foolish to keep pushing them up? Or is it strictly good business sense?

Pentax are clear to point out that the sensor used on the new K-7 isn't the same as the one used on the K20D sporting a “high-speed, four channel image data read-out” compared to the K20D's two. They're confident that the camera will give impressive results and only time will tell when we get a final production model. Coupled to the sensor is a PRIME II processor which is a newly developed upgrade to the original PRIME (Pentax Real Imaging Engine).
 

On the back is a nice large screen which boasts a higher resolution.

The dial on top has a centre locking button which needs to be pressed to change the mode.

The top plate features an LCD screen, exposure compensation and dedicated ISO button.

For the more creative users, the K-7 features the filter settings found on the K-m but also has a new “muted” mode which essentially drops the saturation of the image which looks good on gothic type images. The option to adjust the saturation, contrast, tone and sharpness has always been available but now that's been expanded with high/low key and highlight/shadow contrast adjustment settings.

No DSLR is worth its salt these days if it doesn't have a video mode and the K-7 is no different. It records at 1280x720 30fps which is the bare minimum to be classed as HD quality but not full HD. This could still be useful with the YouTube generation or wedding/event photographers that want to give that bit extra.

Other new features include a HDR function which takes three images of different exposure and composites them to give one image with the widest dynamic range possible. Previously seen on compacts, the K-7 also has the dynamic range cushioning system that prevents over exposed areas from burning out and under exposed areas from going completely black. Similar to Nikon's distortion correction, when you have a Da and Dfa lens attached, you can use automatic compensation for distortion and lateral chromatic aberration.

There's also spirit level which is nothing new, a multiple exposure seen on the K20D and composition adjustment. This is for fine tuning carefully composed images on a tripod and need just a millimetre of movement here or there. The frame can be moved around by using the shake reduction feature to physically move the sensor. This mode and the electric level adjustment are exclusive to Pentax because of the way the Shake Reduction is designed.

Pentax told ePHOTOzine that because it doesn't use rails, the sensor is more manouverable and if the camera detects a slight inclination on the horizon, the camera will automatically correct it for you by moving the sensor to level it out. Of course this is open to imperfections such as perspective and purposefully angled lines but it can be switched off on page three of the camera options in the menu.

Pentax K-7: Build and handling
After the 77 metering segments, a clue to the idea behind the camera's designation appears with the 77 seals to keep moisture and dust proof. It's also cold resistant to -10 which it manages by incorporating a mixture of materials in the skeleton. The K-7 uses a stainless steel frame on a magnesium steel alloy body.

The shutter is newly developed for the K-7 boasting a top speed of 1/8000sec which is pretty good for a camera aimed at this market and it's been tested to 100,000 cycles.

This is easily the best designed camera of all the DSLRs so far. Pentax have gone back to the blocky squareness of old film SLRs that made them popular and it's a pleasure to hold. As I used the pre-production model in London, I felt confident holding it in one hand if it was necessary. However, it's marginally smaller than the K20D and 33% smaller than the Nikon D300. It's also 22% lighter than the Nikon D300 and 9% lighter than the Canon EOS 50D.

Pentax K-7: Focus and metering
The multi-segment metering has been upgraded immensely from 16 segments to 77 on the new model. Theoretically this ensures more accurate exposures due to the higher amount of portions that are taking a reading. The camera also compensates for the composition, format (landscape or portrait) and distance of the subject by using sensors located in the camera body.

Live-view on the K20D was great when the camera was released because it was a relatively new concept on DSLRs at the time but now it looks slow and clunky. The K-7 has had a revamp in the live-view area and now has face recognition and a faster AF system which could be a godsend to current Pentax DSLR live-view users. Out of face recognition, the K-7 uses contrast detection AF and the image stays on the screen when it focuses too.

You can also feel confident using the viewfinder as Pentax have opted for a 100% view using the traditional method. They've also added a petaprism instead of a pentamirror which gives 0.92x magnification.

Pentax K-7: Performance
It's good to see that Pentax have managed to improve on the dire focusing system of the K20D, especially in live view which has now got three types of focusing. It also feels more like a traditional Pentax and I like to think that with the more squared off design, they may be going back to their roots again. It hasn't done Olympus any harm and with the backwards compatibility of the Pentax lenses, they've kept hold of long term owners who might otherwise have chose a different system.

Please be aware that the image of St. Paul's Cathedral was taken on the K-7 with pre-finalised firmware. Pentax Japan have also confirmed that the version of the K-7 that we have here at ePHOTOzine will differ from the version that will be in the shops. They've decided to make minor modifications to the sensor which could result in differences to what you see here.

ePHOTOzine will get hold of a final product for comparison when they're released in early July.

I like the bold primary blue on the colour test chart but I think the other colours are paler by comparison. Earth brown and forest green aren't as boosted as they usually are on other cameras including Pentax models such as the Pentax K-m. The mono tones look ok and I like the skin tone tile but I think more colour could be put into the pastel tiles down the left side of brown, orange and blue.

It was a really bright day on the test for the portraits and the camera struggled with metering in direct sunlight so we went into some shade and I set the white balance to the correct setting. The image still looks very warm though, as though the subject is on holiday as opposed to at the office. It looks nice but is it really appropriate for every type of portrait in the sun?

Adding flash has removed a lot of the warmth and has balanced out the skin tone. Small catchlights are seen in the eyes and their's plenty of detail in the hair.

I like the portrait result although I think it's a little under exposed.

Adding flash has sorted that problem out though.

I retook the detail image of the Agfa Billy vintage camera and I feel that I got a better image this time round which could be down to the finalised firmware. I didn't think I'd see a difference in the finalised images at all but I think they're sharper than before.
 

This detail shot can be compared with the RAW version.

The built-in HDR feature takes three separate images at varying exposure and pastes them together.

One of the most interesting features is the built-in HDR which comes in two varying strengths. This shot of St. Pauls cathedral shows the results quite well and if you prefer the distorted HDR effect over the natural effect found in Adobe Photoshop CS4 then this will be right up your alley. It takes three photographs of varying exposure to get the highlights and shadow detail then merges them in camera.

It works faster than doing it manually which is good for slow moving objects such as clouds that may give a ghosting effect if left too long. However, it still needs a tripod and fast moving objects will still not align properly.

I love the results from the landscape image mainly because it was a lovely day and I was outside but I also like the two butterflies playing. Metering has struggled with the harsh shadows but it's to be expected which is a shame because on days like this I like to underexpose slightly to deepen the sky. More detail would've been lost if I'd done that and on reflection I think the colours are pretty good anyway.

Pentax K-7: Noise test
I'm liking the noise results from the Pentax K-7, not only because they're among the best I've seen from a Pentax model but also because the control that the new processor is commanding over the noise is excellent. The best noise control I've seen so far from a Pentax DSLR is on the K-m, which has 4Mp less, and although noise appears relatively early on, it doesn't even get aggressive at the higher settings which is nice to see.

ISO400 to ISO1600 look roughly on par with each other which is good news for low light shooters who dislike flash.

Pentax K-7 ISO100 RAW image (pending)
Pentax K-7 ISO6400 RAW image (pending)

The ISO100 test.	The ISO200 test.
The ISO400 test.	The ISO800 test.
The ISO1600 test.	The ISO3200 test.

The ISO6400 test.

 

DxOMark provides objective, independent, RAW-based image quality performance data for lenses and digital cameras to help you select the best equipment to meet your photographic needs. Visit the DxOMark website for tests performed on the Pentax K-7.

Pentax K-7: Verdict
I'm so impressed with the K-7 that I think this is one of the most exciting cameras released this year. I think this could rival the Olympus E-620 for the title, which I'm tipping as one of the best DSLRs ever made. It certainly improves on the K20D but then as a higher class this should be a no-brainer.

Of course, as always, I'm not entirely satisfied and I think there's room for improvement in the video area thanks to the release of the new Panasonic DMC-GH1 showing everyone how it's done. The buttons aren't overly responsive but this could be down to the pre-production model so I don't want to put too much emphasis on it.

Established Pentax users will be extremely happy with the new features and picture quality along with the continued backwards compatibility of older Pentax lenses. New comers to the Pentax brand will see new technology that hasn't been seen on any other camera yet as well as proven features that users want and need.

Well done Pentax.

Pentax K-7: Plus points
Faster focusing
Improved live view
Faster frame rate
Good build
Good noise performance
Built-in HDR shooting
PC sync socket

Pentax K-7: Minus points
Portrait underexposed slightly
Colours aren't the best I've seen
No full HD video

FEATURES

HANDLING

PERFORMANCE

OVERALL


I've awarded the Pentax K-7 with the Cutting Edge design for the built-in HDR feature and the Highly recommended simply because it's a good camera.


The Pentax K-7 costs £1199.99 with the new 18-55mm f/3.5-5.6 AL WR lens and is available from Warehouse Express here:


Pentax K-7 & 18-55mm f/3.5-5.6 AL WR