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lenspeeper

Will this result in approximately 1:1 Macro?

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I am considering a macro lens for my Leica TL2. The L mount Macro is 60mm and while yielding 1:1 macro, the focus distance to an animate subject is really too close to be useful.It would tend to make the little critters a bit jumpy. There are other alternatives such as a FF 100mm or 105mm Nikon F mount Tokina or Nikkor with a NIK to L mount lens adapter. That would allow me to stay back from the subject.

So, I am considering a used Leica Macro-Elmar R 100mm lens which, with the macro adapter, results in a 1:1.6 image with a full frame 35mm Leica R camera. So, it seems to me that this lens combination ( lens + Leica R macro adapter) used with an R to L mount lens adapter should yield an image closer to !:1 macro when taking into account the 1.5 sensor ratio between FFG and APSC.

Am I thinking straight, or should I reconsider?  

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The Apo-Macro-Elmarit-TL 60 mm Asph yields 1:1; the Macro-Elmar-R 100 mm with macro adapter yields 1:1.6. A magnification of 1:1 is 1.0×; 1:1.6 is 0.625× ... and 0.625 is less than 1. As simple as that.

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Keep crop factor and magnification separate in your mind. It's easier to work with the dimensions of what you want to capture.

If you are trying to image at 1:1 magnification and you're using a CL, you're trying to capture a 16x24 mm image area. If you're using a Leica M or SL, you're trying to capture a 24x36mm image area. So the first thing to do is to determine what image area you are trying to capture. Once you know the V x H image area, calculate the magnification you need to achieve by dividing one of the format dimensions into the same dimension of the image area.

For example: I have postage stamps that are 40mm x 25mm in size that I want to capture. Since this is not a 2:3 proportion frame, I calculate magnification by working with the long dimension, 40mm. 40 divided by 24mm equals 1.67, so the magnification required is 1:1.67 to fill the frame with the long dimension. That happens to be very close to the maximum magnification achievable by the Macro-Elmar-R 100mm with Macro Adapter-R, so that combination of lens and extension tube would work for this capture with the CL. If I were working with the SL, I'd divide 40mm x 36mm, equalling 1.11 magnification, showing that I'd need a different combination of lens plus extension or close-up lens to achieve the correct magnification to fill the frame with the long dimension. 

Working backwards, I have the Macro-Elmar-R 100mm fitted with bellows mount and the Focusing Bellows-R. If I fit the SL camera to this optical system, this combination can achieve 1:1 magnification and capture a 24x36mm image area. If I fit the CL, this combination can achieve the same 1:1 magnification and capture a 16x24mm image area, which happens to be ~44% of the area that the SL can capture ... the diagonal of which is the crop factor difference of 1.5x. :) If you know the image area of the subject you're trying to capture AND assume the image proportion of 2:3, you can then calculate the magnification you need by working this backwards calculation, but it's more complicated than just knowing the format and the image area you want to achieve. 

Edited by ramarren

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