AA filter or not?

Discussion in 'Digital Photography' started by trjwv, Feb 3, 2012.

  1. trjwv macrumors regular

    Joined:
    Feb 24, 2010
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    kentucky...Go Cats
    #1
    The Nikon D800 is rumored to be available with and without the AA filter. I have googled this and after reading am still a bit confused. Can anyone explain.
    Thanks
     
  2. chrono1081 macrumors 604

    chrono1081

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    Jan 26, 2008
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    Isla Nublar
    #2
    An AA (anti-alaising) filter is used to prevent a moire pattern from showing up on items with fine details (like cloth mostly). I myself wouldn't buy one without an AA filter because while its easy to sharpen an image to make it pop, its almost impossible to remove a moire pattern.
     
  3. thekev macrumors 604

    thekev

    Joined:
    Aug 5, 2010
    #3
    Bleck I've removed many by hand. You can pretty much accomplish it via noise or via more tedious methods if you know them. There are many ways to approach it. Regarding moire and AA filters in general, they're only really used on dslrs these days. Medium format digitals tend to use ccds rather than cmos chips, and up until a few years ago, they weren't that much larger in sensor size than the "full frame" dslrs today, yet they started to drop the use of AA filters from roughly 2004 and on. Sharpening isn't really the same. I'd like to see the day where the whole RGBG array goes away entirely. That design causes a lot of the current problems. Moire in general is just frequency related. If you're getting heavy moire, changing your distance slightly can fix this. The last thing I wish to include is that the damn AA filters don't 100% prevent moire anyway. I'd just look for reviews on the non AA model. If there aren't any weird issues mentioned, I'd go for that one.
     
  4. toxic, Feb 4, 2012
    Last edited: Feb 4, 2012

    toxic macrumors 68000

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    Nov 9, 2008
    #4
    AA filters are used to prevent digital artifacting, the most obvious of which is moiré, but also includes things like stair-stepping. the only way to make AA filters obsolete is by making the spatial resolution of the sensor high enough, i.e. high pixel density.

    MFDBs do not have AA filters because the manufacturers can't afford to make them, not because it's the intelligent engineering decision. I bet Fuji opted to only fix moiré and not any other aliasing in the Pro1 because photographers obviously like having false detail, thinking it's evidence of better sharpness and resolution.

    if you want to know more, look up aliasing or study digital signal processing.
     
  5. Policar macrumors 6502a

    Joined:
    Nov 21, 2004
    #5
    Exactly--although, on MFDBs you're more likely to reach diffraction limited f-stops and/or have a shallow enough DoF that you can deal with this limitation.

    Even with AA filters, dSLRs alias and produce resolution figures suspiciously higher than the theoretical limit...without one, what a nightmare.
     
  6. El Cabong macrumors 6502a

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    Dec 1, 2008
    #6
    There's a post/thread that just went up at NikonRumors discussing the same issue. I'm a bit torn myself, but the deciding factor (for me) will most likely be the degree of the cost difference between the two.
     
  7. toxic, Feb 7, 2012
    Last edited: Feb 7, 2012

    toxic macrumors 68000

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    Nov 9, 2008
    #7
    there is no logical reason to buy an AA-filterless camera. you're paying $300 more for corrupted data, in the case of the D800E.
     
  8. robbieduncan Moderator emeritus

    robbieduncan

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    London
  9. toxic macrumors 68000

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    Nov 9, 2008
    #9
    like I said before, it's not because it was an intelligent decision, it's because they can't make their own filters (Kodak only supplies sensors, not filters), and photographers see the artifacting and think it's sharper and has more resolution.
     
  10. Policar macrumors 6502a

    Joined:
    Nov 21, 2004
    #10
    No. It didn't. Look at the trees here:

    http://www.kenrockwell.com/leica/images/35mm-f14-asph-new/sample-images/L1012275-f4.jpg

    And the wall here:

    http://www.guido-steenkamp.com/wp-content/20100714_L1006324-Bearbeitet-2.jpg

    Scary!

    I wouldn't jump to conclusions re: the Nikon D800E, though. The sample images look incredible and the pixel density might finally be high enough to justify the exclusion of an AA filter.
     
  11. spacedcadet macrumors regular

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    Mar 5, 2009
    #11
  12. macjonny1 macrumors 6502a

    macjonny1

    Joined:
    Jan 10, 2006
    #12
    I *Have* a Leica M9, and the lack of an AA filter is almost NEVER an issue. I'm selling it though....for a Nikon 800E!
     

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