This Image Sensor Makes It Virtually Impossible To Blow Highlights

Image Sensor

Researchers at the German Institut für Mikroelektronik Stuttgart have developed an image sensor that makes it almost impossible to blow highlights with.

What this image sensor does, is using “self resetting pixels“, i.e. pixels that don’t clip when they get saturated but instead starts over and counts the times it has started over. From the research paper’s abstract:

Conventional CMOS image sensors with a linear transfer characteristic only have a limited dynamic range (DR) of about 60–70 dB. To extend the dynamic range considerably, the already successfully demonstrated concept of a linear self-reset pixel was employed in this work. With the self-reset concept the limit of the maximum analyzable photo generated charge (Qmax) during the exposure time is extended to a multiple of the saturation charge of the photo diode (Qsat) by asynchronous self-resets of the photo diode. Additionally, the remaining charge at the end of the exposure time is evaluated to increase the resolution of the opto-electronic conversion. Thus we achieved pixels with a DR of more than 120 dB combined with an improved low light sensitivity using a pinned photodiode.

In other words: you don’t have to worry about your exposure in order to save highlights in your image. Instead, you can set the best exposure for your subject and safely snap knowing that no highlights will be blown out.

This image sensor is a prototype and likely far from going into production. Never the less, it’s a technological innovation that sooner or later will be featured on image sensors.

The full paper “Realization and opto-electronic Characterization of linear Self-Reset Pixel Cells for a high dynamic CMOS Image Sensor” by Stefan Hirsch, Markus Strobel, Wolfram Klingler, Jan Dirk Schulze Spüntrup, Zili Yu, and Joachim N. Burghartz, is available here.

Let’s hope it’s something Canon will research too.

[via Image Sensors World]

Did Canon And Nikon Adopt Telecentric Lens Design For Their Mirrorless Cams, 16 Years After Olympus?

Telecentric

Did you ever hear about telecentric lens design?

Robin Wong had a closer look at telecentric lens design, and explains that:

[…] telecentric lens design [means] having the optics designed in a way that the light will hit the sensor more linearly without too much straying off, and this was already adopted by Four Thirds system lens mount in 2003

This technical approach was used by Olympus 16 years ago, when they introduced the Olympus DSLR E-1.

And Canon and Nikon?

Both Nikon and Canon took the advantage to introduce new mount. Nikon made 2 changes: 1) increase the lens mount throat diameter opening from 47mm to 55mm and 2) reduce the flange back focal distance from 46.5mm to 16mm. Similarly, Canon, maintaining their already large lens mount opening of 54mm (just 1mm shy of Nikon’s new Z mount opening), decreased their flange back focal distance from 44mm to 20mm […][…] having larger glass element to fully envelope the image sensor area allows light to hit the sensor more perpendicularly, and bringing the rear end glass element from the lens closer to the image sensor minimizes light strays and bending. The obvious benefits in terms of technical image quality? Minimized aberrations (chromatic, spherical, etc), improved corner./edge sharpness, and better per pixel optimized light capture overall.

Sound complicated? The video below tells you everything about telecentric lens design in 9 minutes.

[via Robin Wong va 4/3 Rumors]

Preliminary, Non Scientific Tests Suggest Canon’s New 32MP Sensor Improves On Dynamic Range

Canon Eos 90d Dynamic Range

It seems Canon’s claim they managed to improve dynamic range while raising the resolution of their latest APS-C sensor is not wrong.

Fred Miranda forum user cgarcia did some tests with sample images from DPReview to compare dynamic range figures of the new Canon EOS 90D (32MP) and the Canon EOS 80D (24MP).

Canon EOS 90D – ISO 100:

  • DR at 32MP: 12.468
  • DR at 8MP: 13.480 (+1.012)
  • read noise: 2.80125

Canon EOS 80D – ISO 100:

  • DR at 24MP: 12.435 EV
  • DR at 8MP: 13.2343 (+0.7993)
  • read noise: 2.86601

As you can see, there is a small improvement over the EOS 80D.

cgarcia also learned that the dynamic range improves much more at higher ISO settings (compared to the EOS 80D). The image below shows that a higher ISO settings the DR of the EOS 90D improves continously.

Dynamic range comparison between Canon EOS 90D and Canon EOS 80D at different ISO settings (image © cgarcia)

These figures look pretty good. However, keep in mind this is a non scientific test. To be sure we have to wait for further analysis of the performance of Canon’s new 32MP APS-C sensor. Never the less, it appears Canon managed to deliver a quite amazing image sensor.

Canon’s new 32MP APS-C sensor is featured on the brand new Canon EOS 90D and Canon EOS M6 Mark II.

Canon EOS 90D:

Asia & Australia: AliExpress, Amazon JAPAN, Amazon CHINA, Amazon INDIA, Amazon AU, Amazon USA, Digitalrev, Adorama, B&H Photo, eBay Australia, Rakuten JP
Europe & UK: Amazon DE, Amazon UK, Amazon FR, Amazon IT, DigitalRev, eBay DE, Wex Photo Video, Park Cameras, Canon DE, Canon UK, Canon IT, Canon FR
USA/Canada: Amazon USA, Amazon CA, B&H Photo, Adorama, Digitalrev, KEH Camera, eBay US, Canon USA, Canon CA, BestBuy

Canon EOS M6 Mark II:

Asia & Australia: AliExpress, Amazon JAPAN, Amazon CHINA, Amazon INDIA, Amazon AU, Amazon USA, Digitalrev, Adorama, B&H Photo, eBay Australia, Rakuten JP
Europe & UK: Amazon DE, Amazon UK, Amazon FR, Amazon IT, DigitalRev, eBay DE, Wex Photo Video, Park Cameras, Canon DE, Canon UK, Canon IT, Canon FR
USA/Canada: Amazon USA, Amazon CA, B&H Photo, Adorama, Digitalrev, KEH Camera, eBay US, Canon USA, Canon CA, BestBuy

More About The Security Flaw In Canon’s WiFi Transfer Protocol

Security Flaw

Canon yesterday issued security advisory concerning a security flaw in their Picture Transfer Protocol, the WiFi transfer protocol used on Canon cameras.

The security flaw was demonstrated by Israeli security company Check Point Research during DEF CON 2019. The security researchers were able to hijack a Canon EOS 80D using USB and wirelessly using WIFI.

The discovered vulnerabilities would allow a malicious actor to take over a target’s DSLR camera through both WiFi and USB, giving him full control over it. Such an infection could, for example, be used for installing a Ransomware on the camera, and demanding ransom for both the images and the camera itself. Not a nice scenario for professionals.

As LensVid sums it up:

An attacker who would want to use a similar approach to perform a real-world ransomware attack on a EOS 80D will need to set-up a rogue WiFi Access Point and initiate the exploit (something that can certainly be done by many sufficiently experienced attackers although will require the Camera’s WIFI to be turned on).

The video below shows how Check Point Research exploited the Canon EOS 80D using the cited security flaw. By building on existing knowledge of Magic Lantern, they were able to build a ransomware.

All the steps involved in exploiting the security flaw in Canon’s WiFi transfer protocol are documented in this technical article.

Check Point Research promptly informed Canon. While waiting for the firmware updates, Canon recommends the following:

  • Ensure the suitability of security-related settings of the devices connected to the camera, such as the PC, mobile device, and router being used.
  • Do not connect the camera to a PC or mobile device that is being used in an unsecure network, such as in a free Wi-Fi environment.
  • Do not connect the camera to a PC or mobile device that is potentially exposed to virus infections.
  • Disable the camera’s network functions when they are not being used.
  • Download the official firmware from Canon’s website when performing a camera firmware update.

Canon already issued a firmware update for the Canon EOS 80D, and more updates will follow.

Unfortunately, that’s not the end of the story. The researchers found multiple critical vulnerabilities in Canon’s Picture Transfer Protocol. And it’s likely these vulnerabilities are present in other manufacture’s PTP as well.

Stay tuned.

[via LensVid]