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Message: <blockquote data-quote="WayneF" data-source="post: 191348" data-attributes="member: 12496">It seems true that you would have no problem getting closer... closeness would not scare away your prey, nor allow it to reach out and bite you.The 40 or 60mm lens would work.  One issue however, sometimes with a short lens (like these), only a couple of inches from the macro subject, the lens tends to block your light, making shadows on your subject.   The longer lens can stand back and offer a little advantage in that way. And this greater distance may not scare away the grasshopper as soon if using a 105 mm lens.Now, the opposite... if you are shooting a table top scene maybe 18 inches wide, a 105 mm lens on DX probably means the camera must be about 8 feet away....  The room may not offer that much space, and you cannot reach out and rearrange your subject.  The 60 mm lens will be much closer, within easy arms length.This part is not quite right. If the lens is marked, say 60 mm,then the focal length is 60 mm, no matter what.  The lens does not change simply because you put it on a DX body.   A DX lens probably does not have a wide enough viewing angle to cover a FX sensor, but no matter if lens says DX, no matter if camera is DX or FX, no matter what, the lens focal length is what the lens says it is. The DX and FX camera sensors are different sizes, and the FX sees a larger area of the lens projection, and the smaller DX crops away some of what it sees.  So it sees a smaller area, which when enlarged, appears magnified, as if using a longer lens. But all that is different is the 'angle of view" of the lens.See <a href="http://www.scantips.com/lights/cropfactor.html" target="_blank">FX - DX Lens Crop Factor</a>  for more detail.There are two aspects (one for macro).1. For normal use, standing back at 10 feet with a FX camera, will will see the same view that at DX camera will see standing back 1.5x, or at 15 feet, with the SAME lens on a DX camera. That is an "effective" focal length, but it is always what it is.Or the two cameras could stand in same place, and the DX camera would see the same view as the FX if the FX used a lens 1.5x longer focal length. This would be the "effective focal length" (on DX, simply being the view compared to a longer lens on FX), but the focal length cannot change. It is what it is. All that changes is the sensor size, which for DX, offers only a cropped view of the full FX field.The lens is what the lens is, but the angle of view projected onto the smaller DX sensor is smaller.  This is the only difference.2. For macro.To get 1:1 enlargement factor, this 1:1 will be true for DX or FX when all else is the same.  They both have to stand at the same place (at maybe at 2 inches) to get 1:1.  The DX sensor will see a smaller cropped viewing area, but the size of the objects will be the same, 1:1.</blockquote>

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