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requestiong a photo : can some one take a macro picture of a sensor?

Discussion in 'Other Genres' started by ghetto, Dec 11, 2012.

  1. ghetto

    ghetto Mu-43 Regular

    I had a bizzare thought the other day while playing around with macro "stuff".

    1) macro (for m4/3) at 1:1 means you can fill your entire frame with something the size of a full frame sensor... like a full frame sensor.

    2) macro 2:1 means you can fill the entire frame with something the size of a m4/3 sensor...

    3) when I reverse my 17mm lens, I think I can do roughly 4:1, i.e. I can fill the entire frame with about 1.2 cm wide image.

    That had me thinking... if some one has something like a 4:1 (or even 2:1) macro (at say 12mp), and they took a picture of a full frame sensor (say 12 mp full frame sensor) That means at 100% crop we should get about 4 pixels representing each physical pixel on the full frame sensor.

    So... who's got a 2:1 or 4:1 macro and a spare full frame sensor lying around (or even just a spare low mp density sensor). Can some one actually take a picture of a sensor and see the physical pixels?
     
  2. Cruzan80

    Cruzan80 Mu-43 All-Pro

    Aug 23, 2012
    Denver, Co
    Sean Rastsmith
    No, Macro at 1:1 means that the same size that it is in real life is produced on the sensor. The reproduction ratio doesn't change, just how much of the extra you see depends on the sensor (aka. a full frame will see 2x the surrounding area still at 1:1 compared to a m43 at the same focal length). They both still have a 1:1 ratio of reproduction. The field of view is the only "effective 2x" crop factor (which the term seems to have caused more confusion than it helps). Not sure what you mean about 100% crop, as I have only seen it refer to a 1:1 ratio crop of a larger picture.
     
  3. ghetto

    ghetto Mu-43 Regular

    hrmmm there might be a discrepency in the notation used. As far as I can tell when olympus marks a macro lens as doing 1:1 it means you can take a picture of something that's the size of a full-frame sensor. i.e. when I set my lens to 1:1 and I take a picture of a ruler, it is about 3.6cm wide. Not 1.7cm wide. I need what olympus refers to as 2:1 macro to get an image that's only 1.7cm wide.

    But at any rate, the point is, if you take a picture of a sensor, and you get more than 1:1 pixel to pixel ratio on that fov you're imaging, it implies your camera in theory should be able to resolve some details denoting the pixels on that sensor - when looked at at 100% crop.
     
  4. ghetto

    ghetto Mu-43 Regular

  5. arentol

    arentol Mu-43 Veteran

    269
    Jun 29, 2012
    You are mistaken, but don't worry, it happens a lot. 1:1 is 1:1, period. A 17.3mm wide object will fill the final image when photographed at MFD with any 1:1 lens on a m4/3rds camera, even lenses made by Olympus. A 1:1 Canon L lens adapted to an m4/3rds body will do the same. And similarly, it would take a 36mm wide object to fill the final image when photographed at MFD with a 1:1 Canon L lens on a 5d3 (Full frame camera).

    You should be able to verify this very simply yourself if you have ANY 1:1 lens. Just make sure you use Manual Focus and set the lens to 1:1 before you shoot the test. A simple ruler with a metric side would make a good test target.