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 Casio Fujifilm HTC LG Microsoft Nikon Olympus Panasonic Pentax Ricoh Rollei 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
   Nikon D7200 - $829.00
   Canon EOS 750D - $749.00
   Sony Alpha 6000 - $495.00
   Samsung NX3000 - $
   Nikon D3200 - $299.00
   Olympus PEN E-PL7 - $499.00
   Canon EOS M3 - $429.00
   Canon PowerShot SX610 HS - $
   Panasonic Lumix DMC GF7 - $597.99
   Nikon D7100 - $766.95


LetsGoDigital digital camera magazine
Latest Canon announcements
Canon EOS-1D X Mark II professional D-SLR camera
Canon PowerShot SX compact bridge cameras
Canon Imaging products at CES 1016
Canon USA honored with SmartWay Excellence Award
Canon EF-M 15-45mm lens
Canon PowerShot G cameras
Canon PowerShot G5 X
Canon PowerShot G9 X
Canon EOS M10 Compact System Camera
Canon ranked as one of the Best Global Brands
Canon 4K Ultra-HD broadcast lenses
Canon High-Sensitivity Network Surveillance Camera
Canon 4K UHD Wide-Angle Broadcast Lens
Canon 250 Megapixel APS-H-Size CMOS Sensor
Canon 120 Megapixel EOS camera
 
Twitter LetsGoDigital
Latest news headlines
Canon professional handheld video cameras
Sony G Master interchangeable lenses
Sony G Master Standard Zoom Lens
Sony G Master Telephoto Prime Lens
Sony G Master Telephoto Zoom Lens
Nikon SnapBridge App
Sigma 20mm prime lens
Sony A6300 Mirrorless digital camera
Sony Alpha 6300 records 4K UHD video
Olympus 300mm telephoto lens
Nikon D5
Nikon D5 accessories
Nikon D5 features
Canon EOS-1D X Mark II professional D-SLR camera
Samsung Gear 2 smartwatch collection
   
CanonCasioFujifilmNikonOlympusHTCSamsungSonyPanasonicNokia
  Accessories Android Apps Camcorders Digital cameras Mobile phones Smartphones Software Tablets   CES CeBIT Gadgets IFA Photokina PMA