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Thread: What is chromatic aberration?

  1. #1
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    What is chromatic aberration?

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    Hi guys,

    Was checking out on the definition of chromatic aberration and I thought might as well share it here too.

    ________

    When white light passes through a lens (or any glass), and the red, green and blue light does not align back to the same spot after it leaves the glass. That will cause a slight color tinge and reduce sharpness and it's known as chromatic aberration.


    Illustration from York University.

    As a result, this is what you will see...


    Image taken from Macro Lenses Reviewed (canon mount)

    The image from the right suffers from chromatic aberration.


    Here is a better article on chromatic aberration on www.dpreview.com.

    A short article on chromatic aberration on dpreview

    There's also a section on how to reduce the effect digitally.


    Another article by Canon on chromatic aberration


    The effect in aquatic photography is caused by the front glass pane. The thicker, the more obvious it will be, especially when shooting from an angle. This is also the reason why premium lenses does not perform any better than cheap lenses some times. The optics on your premium lenses/equipment is heavily discounted by the aquarium glass.

    Note that in aquatic photography, the fringing effect may not be purple, more often further complicated by a colored light source and tinted aquarium glass.


    There's a few way to avoid/reduce this effect.

    01. Shoot directly perpendicular to the front glass pane

    02. Use ultra clear glass for the front glass pane of your aquarium. Starphire glass is prefered by a lot of serious aquarist, especially for showing the true colors of reef tanks. This type of glass are also of high/optical quality and fairly distortion free.

    Hope the above gives you guys an understanding why there's a color fringe in your pictures sometimes.

    Cheers,
    I have dwarf cichlids in my tanks! Do you?

  2. #2
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    may or may not help

    removing CA in photoshop
    http://forums.dpreview.com/forums/re...essage=7722101

  3. #3
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    Hi Benny,

    Do you know why some digital cameras suffer more from CA than others? Is it due to the quality of the lens?

    I always under the impression that CA in a DC is caused by some imcompatibility between the lens and CCD.


    eggz

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    Does that apply to large format cameras? or less.
    I'm back!

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    CA is lens specific , certain more expensive lenses made using APO process or Fluorite or other Low Dispersion glass helps alleviate CA

    http://www.dpreview.com/learn/?/Glos...rations_01.htm

    http://www.yorku.ca/eye/chroaber.htm

    http://www.canon.com/bctv/faq/chrab.html

    http://www.twcac.org/Tutorials/chrom...aberration.htm

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    shoot in RAW and use Photoshop CS, the RAW processing module allows adjustments to eliminate/reduce CA.
    why I don't do garden hybrids and aquarium strains: natural species is a history of Nature, while hybrids are just the whims of Man.
    hexazona · crumenatum · Galleria Botanica

  7. #7
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    not to be mean, but going onto sony forums at dpreview, you should be able to find lots of algorithms/ps actions to remove CA..


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