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Thread: Removing low pass filter from 5dIII

  1. #1
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    Removing low pass filter from 5dIII

    http://www.eoshd.com/content/7727/ja...ution-increase

    that this was pretty amazing.

    Any thoughts on the impact on a crop sensor?
    If you see me with a wrench, call 911

  2. #2
    Administrator Sean Setters's Avatar
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    I saw that when it first came out. I love it when someone feels comfortable ripping open their new $3500 toy in the hopes of modifying it to make it better.
    Last edited by Sean Setters; 05-17-2012 at 01:43 AM.

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    Admittedly, this guy has the skill and the guts to take it apart. And, I'm sure he doesn't care about voiding the warranty. But, what will removing the low pass filter do to the stills?

    Also, wouldn't the video (with the LP filter in place) be something that could be adjusted in post processing video programs, such as Adobe Premiere, or similar?

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    I just thought of something else...

    Doesn't the low pass filter protect the sensor? Wouldn't that put the sensor at risk of damage if it needed to be cleaned with the cotton swab and/or brush?

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    Quote Originally Posted by shutterdown View Post
    Any thoughts on the impact on a crop sensor?
    It would have a similar impact on a crop sensor. The only difference I can think of is that with smaller pixel sizes, the crop sensor will have slightly fewer cases of aliasing. That is to say that it is more difficult to get the full benefit of a similar pixel count on a crop sensor, so there are more frequent times where there is enough blur (e.g. motion blur) to anti-alias the image.

    Quote Originally Posted by shutterdown View Post
    But, what will removing the low pass filter do to the stills?
    It would improve resolution and contrast at the cost of aliasing. Personally, I'd rather have slightly less resolution and contrast than the increased aliasing artifacts.

    Quote Originally Posted by shutterdown View Post
    Doesn't the low pass filter protect the sensor?
    There are a variety of glass and crystal layers over the sensor, including two anti-alias filters (vertical and horizontal), a red/IR filter, and an IR filter. If all of those were removed (such as for astrophotography or daytime IR photography), then the sensor would need a cover glass to be installed to make it safe for dust cleaning.

  6. #6
    Senior Member neuroanatomist's Avatar
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    Quote Originally Posted by Daniel Browning View Post
    Quote Originally Posted by shutterdown View Post
    Doesn't the low pass filter protect the sensor?
    There are a variety of glass and crystal layers over the sensor, including two anti-alias filters (vertical and horizontal), a red/IR filter, and an IR filter. If all of those were removed (such as for astrophotography or daytime IR photography), then the sensor would need a cover glass to be installed to make it safe for dust cleaning.
    Those multiple layers are arranged in two 'stacks'. The horizontal layer of the AA filter, 1/4-wave plate (what Canon calls the 'phaser layer', necessary to convert the linearly-polarized light from the first filter into circularly-polarized light, else no light would get through the second filter, like when you orient a pair of linear polarizers at 90 to each other, the same principle that variable ND filters use), and the IR cut filter are bonded together. The vertical layer of the AA filter is bonded to the sensor itself (well, on top of the microlens array, which sits on top of the Bayer mask, which sits on top of the sensor).


    The first 'stack' is what vibrates for the 'self-cleaning sensor' (the sensor itself is fixed in place). So, with the hack described above, that assembly was removed, meaning the self-cleaning feature was also removed. The vertical low pass filter is still in place, so the sensor can be cleaned.

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    Quote Originally Posted by neuroanatomist View Post
    The first 'stack' is what vibrates for the 'self-cleaning sensor' (the sensor itself is fixed in place). So, with the hack described above, that assembly was removed, meaning the self-cleaning feature was also removed. The vertical low pass filter is still in place, so the sensor can be cleaned.
    Thanks for the explanation.

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