Pentax K-01 Review
JPEG Tone Curves / dynamic range
Our Dynamic Range measurement system involves shooting a calibrated Stouffer Step Wedge (13 stops total range) which is backlit using a daylight balanced lamp (98 CRI). A single shot of this produces a gray scale wedge from the camera's clipped white point down to black (example below). Each step of the scale is equivalent to 1/3 EV (a third of a stop), we select one step as 'middle gray' (defined as 50% luminance) and measure outwards to define the dynamic range. Hence there are 'two sides' to our results, the amount of shadow range (below middle gray) and the amount of highlight range (above middle gray).
To most people highlight range is the first thing they think about when talking about dynamic range, that is the amount of highlight detail above middle gray the camera can capture before it clips to white. Shadow range is more complicated; in our test the line on the graph stops as soon as the luminance value drops below our defined 'black point' (about 2% luminance) or the signal-to-noise ratio drops below a predefined value (where shadow detail would be swamped by noise), whichever comes first.
Note: this page features our new interactive dynamic range comparison widget. The wedges below the graph are created by our measurement system from the values read from the step wedge, the red lines indicate approximate shadow and highlight range (the dotted line indicating middle gray).
At default settings (Bright) the K-01's tone curve is more or less identical to the K-5 It measures a total dynamic range of 8.5 EV, roughly 3EV of which is in the highlights with a rather abrupt clip to white.
The Bright, Natural, Portrait, Landscape, Vibrant, and BW settings use essentially the same curve and therefore produce the same amount of dynamic range. The Muted setting uses a more linear, less contrasty curve. Bleach Bypass and Reversal Film on the other hand create images with more contrast. However, all the settings clip highlights at the same point.
The tone curve remains essentially unchanged across the ISO range (all ISOs clip at the same point) but at higher settings shadow dynamic range is limited by shadow noise.
Dynamic Range Expansion
The K-01 features two dynamic range tools - Highlight Correction and Shadow Correction, which exemplify the two different methods widely used by cameras to improve the dynamic range conveyed in the final image.
Highlight Correction is the one that actually increases the captured dynamic range - it reduces the camera's exposure by a stop, without boosting the amplification of the sensor's signal (this reduction in exposure is shown as an increase in the camera's base ISO to 200). This reduced exposure means it captures extra highlight detail but it doesn't count as 'underexposure' because a modified tone curve is then applied so that the final image comes out at the correct brightness.
Shadow Correction is a much simpler concept in that it simply boosts the brightness of shadow regions to create a more balanced image. The level of shadow correction is user definable in four steps (Off to 3). There's also an Auto setting in which the camera applies one of these four settings, depending on the contrast in the scene. None of these options increase the Dynamic Range, per se, but can pull detail out of deep shadows so that it's visible in the final image.
Shadow Correction applies only to JPEG images. Highlight Correction applies to Raw as well, since it resulted in a different exposure than the one you'd have used with the feature turned off. A Raw converter that fully supports the K-01 should recognise the need to use a different tone curve to process the result. At worst, with a non-mainstream converter you might have a shot that initially looks underexposed and needs 1EV of extra exposure applied.
The K-01's sensor is almost certainly the Sony IMX071, which is famed for being able to capture detail well down into the shadow regions without contributing much to the noise. This means there's a lot of scope for pushing the exposure down to use more of that shadow region (as the Highlight Correction mode does), and for pulling the brightness of the dark regions up to reveal more detail (as the Shadow Correction mode does). Using the two methods together can start to introduce shadow noise, but the results are an impressive (and accessible) way of showing just how capable the sensor is.
Jul 4, 2013
Jan 31, 2013
May 30, 2012
May 27, 2015
|Patrick Finds Inner Peace by ecastellon|
from Your best photo of the week!
|Forks by Kukla|
from Arranged everyday objects
Starting October 1st, Getty Images will no longer accept images in which the models have been Photoshopped to "look thinner or larger." The change was made due to a French law that requires disclosure of such images.
The 3D printed panoramic film camera known formerly as the "Cycloptic Mustard Monster" is officially available as a DIY kit through Kickstarter.
Snapchat is using its augmented reality tech to replace the sky in your photos. The so-called 'sky filters' can swap out a boring sky for a colorful sunset, rainbows, a starry night, and more.
A court ruling our of Newton, Massachusetts has set an important legal precedent for drone pilots: federal drone laws will now trump local drone regulations in situations where the two are in conflict.
Photographer Mathieu Stern has put together another interesting vintage lens shootout. One model, three lenses, three locations.
From landscapes to motocross and white water kayaking to a wedding, exactly what can't the D850 do?
Calumet UK and Wex Photographic, two of the biggest photography retailers in the United Kingdom, are going to officially merge tomorrow.
macOS High Sierra came out today, but if you use a Wacom tablet you need to wait a few weeks before you upgrade. According to Wacom, they won't have a compatible driver ready for you until "late October."
Do you think a $3,000 Canon 80D video rig can compete with an $80,000+ Arri Alexa setup? Well it can't, but check out this video anyway to see how the rigs compare.
Seven simple rules to make sure you get the most out of your next photography outing.
Vitec, the company that owns popular accessory maker Manfrotto, has just acquired JOBY and Lowepro for a cool $10.3 million in cash. The acquisition adds JOBY and Lowepro to Vitec's already sizable collection of camera gear brands.
A master drone pilot has captured one of the most incredible (and highly illegal) drone videos we've ever seen by flying around, inside, onto, and under a moving train.
Intel just debuted their 8th generation desktop CPUs, and the lineup packs a performance boost for 'content creators' that photo and video editors might be intrigued by.
Canon is developing a 'Free Viewpoint Video System' that will turn real life sports games and events into immersive 3D interactive experiences. It's video game-like camera control IRL.
A veteran photojournalist, Rick Wilking secured a spot in the path of totality for the August solar eclipse. While things didn't quite pan out as predicted, an unexpected subject in the sky and a quick reaction made for a once-in-a-lifetime shot.
The new iZugar 3.25mm F2.5 super fisheye lens offers an insane 220-degree angle of view. That means it can basically see behind itself... good luck keeping your feet out of the shot.
You'll laugh, you'll cry, you'll remember that time you took a picture of the frozen pizza baking directions.
A Craigslist poster has discovered the worst possible way to photograph a car: taking pictures of pictures displayed on a cracked and scratched up smartphone screen.
With the iPhone X coming out soon, the title probably won't last, but the iPhone 8 Plus is officially the best smartphone camera DxOMark has ever tested, and the iPhone 8 is second.
Kodak's new Facebook Messenger chatbot is trying to bring back the 'Kodak Moment' by digging up your old social media photos and trying to sell you prints and custom coffee mugs.
Affinity Photo for iPad was touted as "the first full blown, truly professional photo editing tool to make its way onto the Apple tablet." This update makes it that much more convenient.
Yashica has released a new teaser video, and this one claims they'll be releasing an "unprecedented camera" in October on Kickstarter. Ready... set... speculate!
Storage solutions company Synology has just released its very first 6-bay NAS tower. Combined with the DX1215 expansion units, it can hold and control up to thirty drives.
We're always expanding our collection of product overview content, and we've just added videos for the Canon EOS 6D Mark II, the EOS Rebel SL2 and EOS M6.
The venerable Canon PowerShot G1 was announced seventeen years ago this week, marking the start of a line of enthusiast-focused compacts that's still alive and kicking.
Super macro photographer Can Tuncer captured these incredible close-ups of a single peacock feather using a special setup and three different microscope lenses.
After successfully crowdfunding the Biotar 75mm F1.5, Oprema Jena is at it again. This time they're bringing back the Biotar 58mm F2: the world's only lens with a 17-blade aperture.
Adobe's move to a subscription model is treating it very well indeed. The company has posted record revenue for the second quarter in a row, hauling in a mind-boggling $1.84 billion.
More details have emerged about the potential sale of Blackstone's 45% stake in iconic camera brand Leica.
Popular mobile editing app Snapseed just got a major update that includes a new interface and 11 new presets for both Android and iOS, as well as adding the Perspective tool to the iOS version.