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Thread: One 50mm lens for M9

  1. #51
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    Re: One 50mm lens for M9

    Quote Originally Posted by Brian S View Post
    72-year old Sonnar 5cm F1.5, wide-open on the Leica M9.
    Yes, these old lenses do hold up well. Certainly better than most mid-range zooms in your back-lit image. 'Edge' detail suffers vs modern designs - I have noticed my Summitar is not flat field (edges 'front-focus' the center - ie focus is equidistant from the camera).
    and a Russian J-3, wide-open, on the M8.
    Very interesting bokeh.

  2. #52
    denoir
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    Re: One 50mm lens for M9

    A very simple way of comparing the 50 Cron with the ZM 50/2 (certain aspects anyway) is to look at the MTF charts:



    Leica red, Zeiss black. In the f/4 chart the Leica is actually at f/5.6.

    It pretty much shows the usual Leica & Zeiss difference. Zeiss usually has less field curvature and less astigmatism. Leica usually on the other hand prioritizes minimizing SA & CA.

    There are exceptions, but as a rule of thumb modern Leica lenses are superior wide open and in the center part of the frame while Zeiss ZM tend to be a notch better and more consistent across the frame stopped down. Zeiss also puts more effort in making the sagittal and tangential lines as parallel as possible all the way to the corners. This means that the blur spread is even in all direction giving a stronger impression of crispness.

    Zeiss rendering style is more uniform across the entire product line while Leica lenses show more diversity.

    A good case can (unfortunately) be made for having an overlapping set of Zeiss and Leica lenses as they're good at different things.

  3. #53
    Senior Member leicashot's Avatar
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    Re: One 50mm lens for M9

    Quote Originally Posted by denoir View Post
    A very simple way of comparing the 50 Cron with the ZM 50/2 (certain aspects anyway) is to look at the MTF charts:



    Leica red, Zeiss black. In the f/4 chart the Leica is actually at f/5.6.

    It pretty much shows the usual Leica & Zeiss difference. Zeiss usually has less field curvature and less astigmatism. Leica usually on the other hand prioritizes minimizing SA & CA.

    There are exceptions, but as a rule of thumb modern Leica lenses are superior wide open and in the center part of the frame while Zeiss ZM tend to be a notch better and more consistent across the frame stopped down. Zeiss also puts more effort in making the sagittal and tangential lines as parallel as possible all the way to the corners. This means that the blur spread is even in all direction giving a stronger impression of crispness.

    Zeiss rendering style is more uniform across the entire product line while Leica lenses show more diversity.

    A good case can (unfortunately) be made for having an overlapping set of Zeiss and Leica lenses as they're good at different things.
    I'm curious as to how you can tell SA and CA from these graphs? While the Zeiss is more uniform across the frame, I really see no noticeable advantage of the Leica in the center, in these charts or in my own tests. To me, the Zeiss is the clear winner, and it should be considering it's a much newer lens. Considering Leica's age, it puts up a great fight.

  4. #54
    denoir
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    Re: One 50mm lens for M9

    As a rule you can't tell SA and CA from the graphs, or at least not definitively. SA will appear simply as a drop in resolution, typically in the high frequency components. CA will look like divergence in the tangential and sagittal lines. There could however be a number of other causes, such as astigmatism for instance.

    No, my SA/CA comment was not based on the MTF chart but from experience.

  5. #55
    Senior Member leicashot's Avatar
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    Re: One 50mm lens for M9

    Quote Originally Posted by denoir View Post
    As a rule you can't tell SA and CA from the graphs, or at least not definitively. SA will appear simply as a drop in resolution, typically in the high frequency components. CA will look like divergence in the tangential and sagittal lines. There could however be a number of other causes, such as astigmatism for instance.

    No, my SA/CA comment was not based on the MTF chart but from experience.
    I only ask cause my experience was the opposite with Zeiss having superior control over CA

  6. #56
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    Re: One 50mm lens for M9

    On the older Type 1 Rigid Summicron and Collapsible Summicron, chromatic aberration is so well corrected that the IR index is within the F2 DOF marks. Typically the IR index is found between F4 and F8 for most 50mm lenses.

    A good test of this would be to try the older Summicron on an M8 without an IR cut filter.

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