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Thread: Possible new Leica R formats

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    Member JimBuchanan's Avatar
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    Possible new Leica R formats

    Quote Originally Posted by robsteve View Post
    BTW, I mounted my 180mm APO summicron in front of a view camera and the image circle was 38-40mm. Certainly in MFDB territory and a bigger than 35mm sensor. There are probably other R lenses with large image circles too.
    Robert
    Transposed from another thread, this seeded my math exercise for the day, in light of all the hopla around Photokina . About the FF, 24x36 image circle and a possible new format size from Leica. And, as was replied to above, the FF image circle is 43.2mm.

    So, I grabbed my Summicron-R 50 and projected the horizon onto a white sheet of graph paper, and like robsteve, got an inverted image of almost 2 inches square or an image cirlce of over 60mm. But the image thru the viewfinder is way less, obviously cropped down to the sensor size.

    At first, I thought this COULD support a larger format, but like the field stop of an eyepiece/telescope system, the frame or sensor size acts as a field stop because farther out than that is curvature of field, aberrations, etc. that need to be masked out.

    UNLESS, the Leica designers had the forethought way back in the 90s or indeed this decade, to design into more current R lenses a larger image circle for some future larger format.

    But, I doubt it.

    Anyway, with a 43.2 image circle, it is possible to pull out a square format of almost 31mm, as shown below:
    Attachment 7456

    If Leica did design in a larger image circle as suggested above, by even just a few mm, 2:3 formats larger than 24x36 are easy to visualize. Wonder what CMOS or CCD formats larger than 35mm and smaller than medium format exist? Probably not much to choose from...

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    Senior Member doug's Avatar
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    Re: Possible new Leica R formats

    Quote Originally Posted by JimBuchanan View Post
    If Leica did design in a larger image circle as suggested above, by even just a few mm, 2:3 formats larger than 24x36 are easy to visualize. Wonder what CMOS or CCD formats larger than 35mm and smaller than medium format exist? Probably not much to choose from...
    Why be limited to an existing sensor? A new sensor 27mm x 36mm would allow the exisiting 2:3 proportions or alternatively 27mm x 34mm (8 x 10 proportions) with the existing image circle and many more pixels than 24mm x 36mm cropped to 8x10 proportions.

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    Re: Possible new Leica R formats

    Quote Originally Posted by doug View Post
    Why be limited to an existing sensor?
    If a Leica design requires a unique sensor, it will be more expensive for Leica.

    Transporting 2:3 image size ratio into MF, is interesting, but not typical. The old argument on the MF side is that a 4:3, or similar, is closer to the format of a printed magazine page, so this is what you want.

    Now Leaf just announced a new back with 2:3 ratio; considering 16:9 widescreen, digital projectors etc., it is an interesting move from Leaf - but not typical up to this point.
    --

    If R lenses can produce images larger than 24x36, it still leaves the question open "with what quality out in that farfield". Jim's "square sensor" is interesting, the lenses should be able to support that, but then for the pro-MF market, this might not be acceptable. Which would position Leica MF from the get-go as hobbyist choice.

    Peter

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    Subscriber robsteve's Avatar
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    Re: Possible new Leica R formats

    Jim:

    I think I made a mistake in my original post and the measurement was the radius. In other words the circle was 76-80mm.

    I will have to try it again to confirm, but it was a pretty big image on the 4x5inch ground glass.

    Robert

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