Samsung NX500 Sony CyberShot HX90 Canon PowerShot G3 X Panasonic DMC-FZ330 Nikon Coolpix P900 Olympus Stylus 1s
Samsung NX500 Sony CyberShot HX90 Canon PowerShot G3 X Panasonic DMC-FZ330 Nikon Coolpix P900 Olympus Stylus 1s
  News Headlines APPLE CANON FUJIFILM HTC HUAWEI LG MICROSOFT NIKON OLYMPUS PANASONIC PENTAX SAMSUNG SONY  
Lets Go Digital
 
     
Powered by True
Counted by OneStat.com
Canon low pass filter explanation
Dennis Hissink : February 17th 2005 - 12:00 CET
Digital Camera Review Test Appareil Photo Numerique Prueba camara digital Digitale Camera Test Dijital Kamera Incelemeleri Digitalkamera Test Digitalkamera
CanonCanon low pass filter explanation : Certain fabrics can have a very tight, regular weave. On close inspection, this can appear as a series of alternating stripes separated by dark shadows between the weave. When the pitch of this weave is close to a digital camera sensor's pixel pitch, light from the subject will only activate selected rows of pixels. The sensor will then produce false colours, which can change with rotation or lateral movement of the camera. These false colours appear as waves on the image, known as moiré. Subjects such as distant geometric patterns are also susceptible to producing this effect. To combat the effects of moiré, camera manufacturers sometimes utilize a low pass filter to blur incoming light.
But a single filter can only blur a pattern in one direction, which leaves many false colours uncorrected. Moreover, this approach effectively lowers the camera's resolution.

Canon's approach is to use a unique three-layer Canon low pass filter. The first filter polarises and separates incoming light vertically by precisely one pixel distance. In order to then split the light horizontally, the light must first have the polarisation removed. This is achieved with a second filter known as a phase plate. The third low pass filter polarises the light a second time, only this time separating it horizontally.

Incoming light is therefore spread by precisely one pixel in both the vertical and horizontal directions.

This deliberate blurring has the effect of removing moiré. Unless it is compensated for, however, it also has the effect of reducing image sharpness. Performing accurate compensation, however, requires an exceptionally complex series of processor hungry algorithms, one of the reasons why competing manufacturers have difficulty tackling the moiré phenomenon. One of the Canon's great advantages is the processing 'head room' of its DIGIC II processor, which is used to perform the most sophisticated of correction routines and ensure the benefit of sensor resolution without any trade off in camera performance.

The result is high resolution images with outstanding colour reproduction accuracy.




   PMA 2005 report
   Next  Olympus C-480 ZOOM digital camera introduction
   Previous  Nikon Coolpix 7900 digital camera preview
   News by brand:Canon
   News by category:Innovations
   News by brand and category:Canon Innovations


LetsGoDigital digital camera magazine
Latest Canon announcements
Canon EOS 5D Mark IV
Canon PIXMA All-in-One home printers
Canon PowerShot SX620 HS
Canon EOS Rebel T6 entry-level DSLR camera
Canon PowerShot ELPH 360 HS
Canon PowerShot ELPH 190 IS
Canon PowerShot ELPH 180
Canon EOS 1300D
Canon smartphone app update
Canon EOS 80D
Canon PowerShot G7 X Mark II
Canon PowerShot SX720 HS
Canon EF-S 18-135mm zoom lens
Canon 80D accessories
Canon IXUS digital cameras
 
Twitter LetsGoDigital
Latest news headlines
Canon EOS 7D Mark II bundled with W-E1 adapter
Canon EOS 5D Mark IV
Mobile World Congress 2017
IFA 2016 Smart World Summit sessions
Logitech protective keyboard case for iPad Pro
Photokina 2016 photography exhibitions
Kyocera DuraForce Pro Android smartphone
IFA 2016 Trade Show Berlin
Galaxy Note7 U.S. Cellular
Nikon D3400
Nikon telephoto lenses with AF-P stepping motor
Photokina 2016 news update
Vodafone 5G enhanced mobile broadband
OnePlus 3 Premium smartphone
Philips monitor with popup web camera
   
CanonCasioFujifilmNikonOlympusHTCSamsungSonyPanasonicNokia
  Accessories Android Apps Camcorders Digital cameras Mobile phones Smartphones Software Tablets   CES CeBIT Gadgets IFA Photokina PMA