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Thread: 20/1.7 G1<->E-P1 unexpected difference

  1. #1
    Lupo
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    Question 20/1.7 G1<->E-P1 unexpected difference

    20/1.7 an G1 & E-P1 at dpreview.com

    I am very surprised about the great differences

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    Re: 20/1.7 G1<->E-P1 unexpected difference

    Quote Originally Posted by Lupo View Post
    20/1.7 an G1 & E-P1 at dpreview.com

    I am very surprised about the great differences
    May be because of the different focal lenghts between the two measurements?
    Michiel

  3. #3
    JohnF
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    Re: 20/1.7 G1<->E-P1 unexpected difference

    Hi -

    Well, given the in-camera correction of distortion, it shouldn't be a surprise that the 20 from Panasonic didn't do as well on the Olympus.

    It's perhaps not surprising - yet altogether disturbing - that Panasonic should effectively force you to use their lenses on their bodies for optimal performance, but given how they won't run on third-party batteries...

    Nonetheless, while the idea of in-camera correction of lens distortions is definitely cool, it means that when you put that lens on another camera, you get that distortion...whether you want it or not.

    :-)

    JohnF

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    Re: 20/1.7 G1<->E-P1 unexpected difference

    With a higher list price, I would expect the Pana lens to perform better.

    It would be interesting if they make a direct comparison to the costs vs the MTF chart differences.

    The 45mm Pana should perform ~3 times better than the 17mm Oly-D.

    The GF-1 ~2 times better than the G1...

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    Re: 20/1.7 G1<->E-P1 unexpected difference

    lupo

    your link shows the difference between the 17mm on the E-p1 and the 20mm of the GF1

    Not the 20mm lens on both cameras as you link implies

    K

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    Re: 20/1.7 G1<->E-P1 unexpected difference

    ... you can set the chart to show the 20mm on both bodies... the CA on the olympus seems much worse... but that is presumably corrected in the camera on the GF1 and not on the E-P1.... maybe time fr another firmware update :-)

    K

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    Re: 20/1.7 G1<->E-P1 unexpected difference

    Quote Originally Posted by kevinparis View Post
    lupo

    your link shows the difference between the 17mm on the E-p1 and the 20mm of the GF1

    Not the 20mm lens on both cameras as you link implies

    K
    Indeed that is what I said!
    Michiel

  8. #8
    Lupo
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    Re: 20/1.7 G1<->E-P1 unexpected difference

    Sorry, can not explain the error.

    But now the right thing:
    20/1.7 to E-P1 & G1

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    Re: 20/1.7 G1<->E-P1 unexpected difference

    There aren't big differences with the lens on each camera. The bigger difference is the CA shown at the bottom. Panasonic cameras correct for it and Olympus cameras don't but this is a case of having to read the text in the review where they say that the lens is not problematic from a CA point of view so you really shouldn't worry about it.

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    Re: 20/1.7 G1<->E-P1 unexpected difference

    Pana software upgrade correct CA for Pana lenses (and Oly lenses). Oly need a different version since the AA/IR/UV cut filter is different.

    Carl has shown that the E-P1 is a bit more responsive to IR than the G1. That makes a difference.

    From what I see, most c-mount 25mm lenses do well.

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    Re: 20/1.7 G1<->E-P1 unexpected difference

    While the Panasonic camera corrects the CA and the Olympus doesn't, you get IS with the Olympus but not the Panasonic. Win some and lose some. From the looks of the review, the Panasonic on the Olymplus seems fine.

    I would like to see a detailed side by side photo comparision of the 17mm Olympus and 20mm Panasonic on the E-P1.

    I really don't know what to make of those charts - I want to see photos - the real world.

    On charts, here is the 20mm f/1.7 and the 14-42 Olympus zoom on the E-P1 with the zoom set to 18mm. The 14-42 has already got a reputation as being a fairly good kit zoom and as far as sharpness goes, the 20mm is better and CA, while differing in the results for red-blue, pretty much similar levels when both are taken into account. I haven't found a situation where I have had problems with CA with the 14-42 zoom.

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    Re: 20/1.7 G1<->E-P1 unexpected difference

    That is very interesting, if the test is repeatable.
    It is suggestive of there being no AA filter, or perhaps an over-weak filter, on the G1 as there appears to be frequencies above the Nyquist limit (aliasing artifacts).
    Now when this occurs on some cameras, the owners praise it as the result of super lenses, but it is really just a form of sampling noise. The AA effect seems about perfectly tuned on the E-P1.
    I really wonder if they did that test correctly.
    -bob

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    Re: 20/1.7 G1<->E-P1 unexpected difference

    Quote Originally Posted by TEBnewyork View Post
    There aren't big differences with the lens on each camera. The bigger difference is the CA shown at the bottom. Panasonic cameras correct for it and Olympus cameras don't but this is a case of having to read the text in the review where they say that the lens is not problematic from a CA point of view so you really shouldn't worry about it.
    The MTF differences are huge at all apertures, especially at the edge of the field. Since these lenses will typically be used for scenes and not portraits, this is important. The Panasonic clearly bests the Olympus. Unless you really need that extra 3mm (and you may) I'd go with the 20mm.

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    Re: 20/1.7 G1<->E-P1 unexpected difference

    Quote Originally Posted by RichA View Post
    The MTF differences are huge at all apertures, especially at the edge of the field. Since these lenses will typically be used for scenes and not portraits, this is important. The Panasonic clearly bests the Olympus. Unless you really need that extra 3mm (and you may) I'd go with the 20mm.
    We are talking apples and oranges. Clearly the 20mm lens is better than the 17mm lens. In my post I was talking about the results of the same 20mm mounted on each body. Read through the post the first link is to a comparison of two different lenses. Further down is a link comparing the same lens on two different cameras.

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    Re: 20/1.7 G1<->E-P1 unexpected difference

    There is correction done to CA and distortion via the Panasonic software which gives it an edge over the Olympus lens, but apart from that, the 20mm still stands out as the superior lens as far as contrast and resolution are concerned.

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    Re: 20/1.7 G1<->E-P1 unexpected difference

    Quote Originally Posted by Bob View Post
    That is very interesting, if the test is repeatable.
    It is suggestive of there being no AA filter, or perhaps an over-weak filter, on the G1 as there appears to be frequencies above the Nyquist limit (aliasing artifacts).
    Now when this occurs on some cameras, the owners praise it as the result of super lenses, but it is really just a form of sampling noise. The AA effect seems about perfectly tuned on the E-P1.
    I really wonder if they did that test correctly.
    -bob


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    Re: 20/1.7 G1<->E-P1 unexpected difference

    why is there a difference at sharpness (E-P1 lower),both have the same sensor or not?

    Yogi

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    Re: 20/1.7 G1<->E-P1 unexpected difference

    Quote Originally Posted by mod2001 View Post
    why is there a difference at sharpness (E-P1 lower),both have the same sensor or not?

    Yogi
    Panasonic G1/GF1 have lighter AA filters than the E-P1, apparently.

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    Re: 20/1.7 G1<->E-P1 unexpected difference

    BTW, Bob, dprevs appears to have changed the results.

    The f/1.7 is absent and f/1.8 is now below the Nyquist limit.

    in the 201/1.7 "tests" everything has been brought down below the Nyquist limit.

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