DxOMark introduces 'Perceptual MPix' score for lens sharpness
DxOMark has introduced a new metric of lens sharpness that it's calling the 'Perceptual MegaPixel'. This is designed to give a simple, easily-understandable indication of how a lens impacts on the resolution of the camera with which it's paired. The measurement is based on standard MTF (Modulation Transfer Function) testing, but also takes into account the sensitivity of the human visual system to detail. The data can be explored over at the DxOMark website, www.dxomark.com.
Our lens reviews are prepared in partnership with DxOMark, using test data shot in its labs. Do you think the 'Perceptual Megapixel' would be a useful number to include in our reviews? Let us know in the comments below.
DxOMark introduces the Perceptual Megapixel as a new unit for measuring the perceived sharpness of lenses
A simple way to quantify the impact of lens sharpness on camera resolution
December 17, 2012 - DxOMark, the website of reference for measuring the image quality of digital cameras and lenses, announces the launch of the Perceptual Megapixel, its new measure of lens sharpness. Expressed in units already well-known to the general public, the Perceptual Megapixel provides photographers with a means of instantly understanding the performance of a lens by quantifying its impact on the perceived resolution of the camera with which it is coupled.
A measurement correlated to human vision
Designed by DxOMark experts, Perceptual Megapixel quantifies the sharpness "perceived" by the photographer while taking into account all the characteristics and defects of the lens and the camera.
"This new unit of measure replaces the MTF scores that we have been publishing up until now. Perceptual Mpix weights MTF measurements with the sensitivity to detail of the human visual system, thus providing a score for the sharpness perceived by our eyes. We think this new measurement will be more understandable and practical for photographers who use our website," explained Frédéric Guichard, Chief Scientific Officer for DxO Labs.
An average of 45% of all megapixels lost
The Perceptual Megapixel measurement allows for making numerous comparisons among cameras and for the first time quantifies the impact of lens sharpness on camera resolution. Thus the perceived resolution for a camera can be significantly different from the native resolution depending on the lenses with which it is coupled.
For example, when coupled with a Canon EOS 5D Mark II camera with a 21.1 Mpix sensor, a Sigma 35mm F1.4 DG HSM lens has a Perceptual Mpix score of 17.2, whereas a lens such as the Carl Zeiss Distagon T* 35mm f/1.4 ZE has a Perceptual Mpix score of 15.2.
The example above is based on data from DxOMark's database of test reults for more than 2,700 camera and lens combinations. These tests reveal that, on average, about 45% of the resolution is lost due to lens defects.
"The Perceptual Megapixel measurement allows photographers to step away from manufacturers' announcements about resolution and to answer a key question when the time comes to change equipment: would it be better to buy a new camera or a new lens?" observed Nicolas Touchard, VP Marketing, Image Quality Evaluation, for DxO Labs.
This new metric introduced by DxOMark aligns with the standardization work currently being undertaken by the IEEE, the International Imaging Industry Association (I3A), and the ISO - and in which DxO Labs actively participates. Perceptual Mpix is also based on the scientific findings of CNES (the French space agency) pertaining to the optimization of digital acquisition, notably in the field of satellite imagery.
More than 2,700 camera/lens combinations available
Freely available to all, DxOMark has been designed to serve the entire photographic community, from serious amateur photographers to photo experts and journalism specialists. It has a threefold mission: to provide objective measurements of digital cameras and lenses; to analyze camera and lens performance; and to provide a means for making meaningful comparisons.
DxOMark now has a database of more than 2,700 available camera/lens combinations. Dozens of DxO Labs engineers and technicians in six DxO laboratories perform these measurements, taking a photo every 10 seconds. Testing protocols are entirely reproducible and conform to the international standards established by the Camera & Imaging Products Association (CIPA), the International Imaging Industry Association (I3A), and the Camera Phone Image Quality (CPIQ) group.
|Iconic Tree by Jerry-astro|
from Fall colors
|USA1053a by embie|
from We salute you!
|Pot of Gold by Take5|
from Flower center
|Zombie DP by MarioSS|
The Profoto A1 most certainly isn’t for everyone [...] But for those who are used to using the Profoto systems, and want something that pairs seamlessly with the strobes you already have, there is no better companion.
Fujifilm has asked a US district court to clear it of any wrongdoing, after allegedly being threatened with trademark litigation by Polaroid.
While a couple of our reviewers are out testing the Sony a7R III in Arizona, back in Seattle we slapped the camera in front of our studio scene to get a close look at its image quality. See how it stacks up against the competition.
We're counting down our top 10 most popular sample galleries of 2017, and the #8 ranking belongs to the Nikon D7500.
B+W has announced a new aluminum filter holder that offers three slots so users can use multiple filters at the same time. The holder goes with the 2mm thick 100mm square filters it launched earlier this year.
8K video is coming a lot faster than you think, and Blackmagic is ready for it. Meet the DeckLink 8K Pro, a new high performance PCI-E capture and playback card built to handle 'real time high resolution 8K workflows.'
"Glass is everywhere in photography. From Eugène Atget’s reflective vitrines to Lee Friedlander’s sly self-portraiture, photographers have long been in thrall to the visual complications glass can inject into a composition."
Former Apple Aperture lead developer Nik Bhatt has designed an iOS app called RAW Power that lets you edit raw photos from your professional camera using your phone and tablet.... color us intrigued.
Advertising photographer Blair Bunting got his hands on the new Microsoft Surface Book 2, and it blew him away. Bye bye MacBook Pro...
The OnePlus 5T retains many of the 5's features and specs, but comes with an edge-to-edge display and a dual-camera that is optimized for low light.
Sony's recently announced IMX461 backside illuminated medium format sensor will bring 100MP resolution and almost 2x the speed to the next-gen Fuji GFX and Hasselblad X1D.
With the ‘Rent a Hasselblad’ camera equipment renting program, the camera makers is aiming to give enthusiast and professional photographers easier access to its medium-format photography products.
They say seeing is believing, and that's exactly what happened when one DPR staffer took the Google Pixel 2 out for an afternoon shooting under challenging conditions.
We're counting down our top 10 most popular sample galleries of 2017. At the #9 spot we have the Fujifilm GFX 50S, a medium-format camera that took CP+ 2017 by storm.
Instagram is testing a new feature that lets you follow hashtags in addition to people, making it possible to keep track of your favorite #landscapes or #portraits without leaving your home feed.
Despite the gigantic volume of second hand film bodies in existence, it seems there is still a demand for new 35mm SLRs with a retro feel. The latest is a remake of the Ihagee Elbaflex from the 1960s, but with a Nikon F mount.
The Polaroid Insta-Share Moto Mod straps an instant printer directly to your Moto Z smartphone, so you can print your photos as soon as you've captured them.
The Mitakon Speedmaster 135mm F1.4 lens is being relaunched in 7 different mounts, including: Sony A, Sony E, Canon EF, Nikon F, Fujifilm G, Pentax K, and Leica L. Got an extra three grand lying around?
In January, Kodak announced it would bring back the beloved slide film Ektachrome. The timeline has been pushed back a bit, but Kodak says you can expect to purchase Ektachrome again in 2018.
Instagram popularity is threatening some of the most beautiful landscapes in the US, as hordes of 'nature lovers' trample over the same spots over and over again in search of the same exact shot.
You’d have to be pretty brave to immerse your $50K RED cinema camera underwater. But if you've got the guts, Gates just released a new housing you can be pretty sure won't wreck your unbelievably expensive toy.
Adobe has released a 'Lightroom Downloader' app for Windows 10 and macOS High Sierra that allows you to download all of your images from the Adobe Cloud, all at once.
After releasing a popular 4K action cam and an affordable mirrorless M43 camera, Chinese camera maker YI is diving into yet another market: 360° VR. Meet the YI 360 VR: a powerful little two-lens camera that can shoot and stream in 4K.
The DJI Spark has received a lot of attention thanks to its diminutive size, but how does it stack up? In our review, we take a look at what it's like to fly this pint-sized drone, as well as what's in it for photographers.
Between now and the end of the year we'll be counting down our top 10 most popular sample galleries of 2017. Coming in at #10 is a fast wide prime and part of the highly-acclaimed Sigma Art series.
DxOMark has awarded the Pentax 645Z 101 points, making it the second-highest scoring medium format camera it's tested (or the highest scoring from 2015 to now, based on the originally published results).
A small explosion that sounded like a gunshot caused a panic and 24 flight cancellations at Orlando International Airport last Friday. As it turns out, it was a camera battery that exploded inside a traveler's bag.
At last, a premium superzoom bridge camera with phase detect autofocus. Is this the best all-in-one camera ever made? Read on.
Unlike most smartphone cameras, the new Google Pixel 2 devices combine optical and electronic image stabilization for a smooth video experience. Here's how it works.
It might be tempting to skimp on a wedding photographer and 'crowdsource' your wedding photos instead. But as this couple found out, you could end up with no photos and a big headache.