Strength of N1-CL1 Closeup Lens?
Thanks DesertCat, but I would like to get a strength comparison with other closeup lenses. I think the 3.8x is an "effective" magnification but that the actual magnification is 1.4x when considering the 2.7 crop factor.
I tried using the minimum focus distance of 0.24 m together with the 1 m minimum focus distance of the 30-110 mm lens:
1/.24 = 1/x + 1/1 ==> x = .316 m = 316 mm ==> 3.16 diopters
When I do the same thing for the10-30 mm lens (min focus = 0.2 m) and min focus with the N1-CL1 attached is 0.09 m:
1/.09 = 1/x + 1/.2 ==> x = .164 m = 164 mm = 6.1 diopter
The two calculations are not consistent with each other, probably because the formula isn't accurate unless you use the correct reference points for the focus distances. So I can't trust the formula and Nikon's "effective magnifications" at minimum focus do not help either.
Usually for closeup lenses, the specs include a diopter value. Why doesn't Nikon provide one?
The maximum magnification of a closeup lens usually occurs for infinite focus of the camera and, in that case, the working distance for the closeup lens is its focal length. It sounds as though Nikon is saying that its Nikon 1 system is different and that its maximum magnification occurs at minimum focus.
The only thing I would trust now is a direct measurement of the N1-CL1's focal length.