Pentax K-7 Review
ISO Sensitivity / Noise levelsISO equivalence on a digital camera is the ability to increase the sensitivity of the sensor. This works by turning up the "volume" (gain) on the sensor's signal amplifiers (remember the sensor is an analogue device). By amplifying the signal you also amplify the noise which becomes more visible at higher ISO's. Many modern cameras also employ noise reduction and / or sharpness reduction at higher sensitivities.
To measure noise levels we take a sequence of images of a GretagMacBeth ColorChecker chart (controlled artificial daylight lighting). The exposure is matched to the ISO (i.e. ISO 200, 1/200 sec for consistency of exposure between cameras). The image sequence is run through our own proprietary noise measurement tool (version 1.5 in this review). Click here for more information. Room temperature is approximately 22°C (~72°F), simulated daylight lighting.
Pentax K-7 vs. Pentax K20D vs. Nikon D300 vs Canon EOS 50D
- Pentax K-7: Pentax 50 mm F1.4 lens, Manual Exposure, Manual WB,
Default Parameters (Bright), High ISO NR default (Medium), JPEG Large / Premium
- Pentax K20D: Pentax 50 mm F1.4 lens, Aperture Priority, Manual WB,
Default Parameters (Bright), High ISO NR off, JPEG Large / Premium
- Nikon D300: Nikkor 50 mm F1.4 lens, Manual Exposure, Manual WB,
Default Parameters (Normal), High ISO NR (Normal), JPEG Large / Fine
- Canon EOS 50D: Canon 50 mm F1.4 lens, Aperture Priority, Manual WB,
Default Parameters (Standard PS), High ISO NR Default (Standard), JPEG Large / Fine
|Pentax K-7||Pentax K20D||Nikon D300||Canon EOS 50D|
As usual in our ISO-noise comparisons the differences between the contenders are pretty marginal up to ISO 400. From ISO 800 onwards the cameras' varying noise characteristics become more visible. The K-7 and K20D show visibly more of both luminance and chroma noise than the Nikon and Canon. The D300 maintains a good balance between noise and image detail up to the highest sensitivities while the EOS 50D's approach to noise reduction is more heavy-handed and results in more blurring of fine detail than on the Nikon.
Despite representing two different camera generations the K-7 and K20D produce near identical output up to ISO 800. From ISO 1600 upwards on the K-7 noise reduction kicks in whereas on the K20D noise reduction is switched off at default settings. While this naturally results in a larger amount of chroma noise on the K20D at higher sensitivities, the difference in luminance noise is fairly small. However, selecting the 'Weak' noise reduction setting on the K20D the differences pretty much disappear.
At higher sensitivities it's obvious that Pentax is applying far less luminance noise reduction than Canon or Nikon. On the plus side this means that detail is retained and the results look visibly sharper; the downside is that noise is, inevitably, considerably more obvious. On balance, for viewing at normal magnifications (when color noise is still visible), the Canon and Nikon approach is preferable for JPEGs (though once you get to ISO 6400 none of them is that impressive).
The graphs below confirm what we have seen in the sample crops above. In numerical terms the K-7 teams up with its predecessor in being the noisiest camera in this group of four cameras. Up to ISO 400 the differences are manageable but then the gap opens up and measured noise on the Pentax duo goes pretty much through the roof.
Finally let's take a look a the K-7's RAW output next to the competition. Removing any in-camera noise reduction and processing the images using Adobe Camera Raw (V5.4 in this case, all NR set to 0) gives us the nearest thing to a 'level playing field' for assessing the relative noise levels of the four cameras' sensors.
With noise reduction turned off we get a more accurate idea of how noisy these sensors are and the image looks slightly different to what we've seen above in the JPEG section of this page. In the RAW comparison the K-7 and K20D can easily keep up with the competition from Nikon and Canon. Surprisingly the older model K20D even outperforms its successor at higher sensitivities and produces slightly cleaner RAW files.
|Pentax K-7 RAW||Pentax K20D RAW||Nikon D300 RAW||Canon EOS 50D RAW|
Raw Noise graphs
The graphs below confirm what we can see in the sample crops. The four cameras compared here produce similar amounts of noise at all ISO settings. The EOS 50D measures the largest amount of chroma noise and the K20D is producing the lowest RAW noise levels pretty much across the range.
- 1 Introduction
- 2 Specifications
- 3 What's new
- 4 Body & Design
- 5 Body & Design
- 6 Body & Design
- 7 Operation & Controls
- 8 Operation & Controls
- 9 Operation (Live View)
- 10 Displays
- 11 Menus
- 12 Menus
- 13 Menus
- 14 Performance
- 15 Photographic tests (RAW)
- 16 Photographic tests (Noise)
- 17 Photographic tests (Noise)
- 18 Photographic tests (DR)
- 19 Photographic tests
- 20 In-camera effects
- 21 Movie Mode
- 22 Compared to
- 23 Compared to (JPEG)
- 24 Compared to (JPEG)
- 25 Compared to (JPEG)
- 26 Compared to (RAW)
- 27 Compared to (RAW)
- 28 Compared to (RAW)
- 29 Compared to (Higher ISO)
- 30 Compared to (Resolution)
- 31 Compared to (Resolution)
- 32 Conclusion
- 33 Samples
Sep 14, 2012
Sep 14, 2012
Oct 2, 2009
Jan 17, 2011
|2014_1211_140657AA by old shutter bugger|
from The Bride
|Overloaded by NZ Scott|
from Your City - Delivery Boy
|Barley by Will B Milner|
|APPLE & ROACH by TX Photo Doc|
from Delicious - Unpalatable
Try your hand at this blind portrait shootout between the Canon 1DX Mark II, Nikon D5 and Sony a9. With all bias removed, you might just rank your favorite camera brand worst.
Photo sharing site 500px has just added support for wide-gamut color profiles such as AdobeRGB and ProPhotoRGB, even allowing users to filter their searches by color profile.
DJI just released a mandatory firmware update for the DJI Spark. If you own a Spark and don't update your firmware by September 1st, DJI will remotely ground your drone.
Affordable flash manufacturer Godox has updated its smartphone app so that it can be used to control all of its wireless X flash units, not just the A1 smartphone flash.
Western Digital's new My Book Duo external desktop storage system offers up to 20TB of storage capacity, and comes with RAID-optimized WD Red hard drives.
Version 1.04 of the Sony a6500 firmware can be downloaded from the Sony Support website now.
Not sure how to choose your first drone? In this article, the second of a 3-part series, we discuss what factors you should consider when deciding what drone is right for you.
NASA photo editor Joel Kowsky didn't just capture the solar eclipse from his vantage point in Wyoming, he also managed to capture the ISS buzzing across what remained of the sun.
In these videos, talented photographer and filmmaker Daniel DeArco breaks down several tips that will help flash photography newbies start experimenting with artificial light.
Photographer and master potter Steve Irvine makes incredibly intricate, functional ceramic pinhole cameras that look like robots and monsters.
Chinese gimbal manufacturer Gudsen has released a firmware update for its Moza Air that lets you control the direction and angle of the head remotely just by moving a small handlebar-mounted control unit.
Curious how the Sony a9 performs underwater? Our friends at Backscatter took the camera diving off the Baja California coast, to find out how it handled shooting great white sharks.
While most of the DPReview crew put away our cameras and just watched the celestial event, Rishi decided last-minute to hack together a rig and capture a few shots.
Defunct Russian camera maker Zenit is making a comeback, and they're planning to release a full-frame mirrorless camera in 2018.
The days where you're more or less locked into premium or first-party flash units has gone. They're less than $50 now, so there's one less excuse not to get one. Here's our case for adding one to your kit, and a few pointers to get you going.
If you're shooting the solar eclipse here's a hint: don't fry your camera's sensor. Use a proper solar filter that offers at least 16 stops of light filtration, along with UV and IR filtering. More important? Don't look at it unless you've got solar filters. Sensors can be replaced, your retinas can't.
Photographer Rick Wenner recently captured an odd event called the Race of the Gentlemen with a rather odd camera: The Phase One XF IQ3 Achromatic, the world's only 101MP black-and-white digital back.
Buying used is a good way to save some dough, and with the right precautions you can protect yourself from falling victim to a scam.
This two-part video series takes a deep dive into the world of dynamic symmetry and geometric composition, using iconic photographer Henri Cartier-Bresson's brilliant photographs as a guide.
Award-winning photographer Jeremy Cowart tells the moving story behind this drone photograph, captured in the aftermath of the devastating wildfire in Gatlinburg, TN in 2016.
Happy 2017 World Photo Day! We asked everyone on staff at DPReview to share one photo that they took within the last year that makes them jazzed on photography. Here's what we chose.
French President Emmanuel Macron has lodged a legal complaint against a paparazzo who snuck onto the president's private vacation property to take pictures.
Ever wonder what the difference is between compressed, uncompressed and lossless compressed Raw files? Photography Life's Nasim Mansurov breaks it down for you in this informative article.
The oldest known portrait of a US president was just discovered after over a century in storage. It's going up for auction in October, where it's expected to fetch between $150,000 and $250,000.
If you're using the popular Sigma 24-70mm F2.8 Art lens with Sigma's MC-11 converter, listen up: you'll want to update your lens and converter firmware ASAP.
If you've heard it once, you've probably heard it a thousand times: never check in your camera gear when flying. This shattered $11,000 lens is what can happen when you do.
Lensrentals just did its first Cine lens comparison, pitting five top-notch 35mm primes against each other: the Zeiss CP.2 35mm T2.1, Canon CN-E 35mm T1.5, Sigma 35mm T1.5 FF, Rokinon Xeen 35mm T1.5 and Schneider Xenon 35mm T2.1.
A team of Google researchers have found that slightly warping watermarks when embedding them into images can help prevent automatic removal.
You don't have to empty your savings account to take your photography to the next level. These cheap buys cost about $50 or less, and come with outsized benefits for your photography.
Joey L, Dani Diamond, Brandon Woelfel and Jessica Kobeissi go head-to-head in an episode of "4 photographers shoot the same model."