Do filters affect AF?

Discussion in 'Accessories' started by snegron, Jun 6, 2013.

  1. snegron

    snegron Mu-43 Regular

    166
    May 9, 2013
    SW Florida
    I attached my new circular polarizer filter on my G5's 14-42 kit lens, and noticed that the camera is having trouble focusing. Without the filter my G5 focuses quite well, but with the filter attached it is hunting, having a difficult time locking focus on simple targets. Is this normal for the AF system? I have used circular polarizers on my AF DSLR's without a problem. Is this a particular quirk of the G5?
     
  2. heli-mech

    heli-mech Mu-43 Top Veteran

    959
    Mar 9, 2012
    Vancouver Island, Canada
    Andrew
    It shouldn't other than the fact a polarizer does act like a light ND filter so there is less light making it to the sensor. Maybe in lower light this light loss would effect AF. Only other thing would be if it is a really cheap filter that might be causing blurring that is confusing the camera.
     
  3. flash

    flash Mu-43 Hall of Famer

    Apr 29, 2010
    1 hour from Sydney Australia.
    Gordon
    I find this on my cameras as well. Its because the focus system has a required amount of light to work well. More so on slower optics. Also contrast is affected which may make some difference as well. A 6 stop ND made my EM5s give up even tryingbto focus in some rainforrests, recently.

    Gordon
     
  4. snegron

    snegron Mu-43 Regular

    166
    May 9, 2013
    SW Florida
    I'm guessing you are probably right regarding the effect of less light reaching the sensor with filter attached. My LCD screen compensates for lower light, but in reality there is less light reaching the sensor.