<p>Actually, camera's like the MZ-7 or MZ-50 are working the same way with these values.<br>
This is: the lens is electronically coupled with the body, not with the mechanic coupling for the aperture.<br>
Actually, the lens is telling the body a signal that a certain diafragm/scale will be in use and the body selects / calculates a certain value of which therefore the time should be set to.<br /> Since the body is only coupled electronically and this info is provided with open-aperture, this calculation is not always optimal.</p>
<p>But, if you recalculate in the way the aperture is calculated it is pretty correct in most cases. Remember the aperture-number is a calculation of f/number, thus the longer the lens, the higher te outcome will be with most lenses. This is extra if the lens is put in macro-setting (yes, there will be less light, as if the "f" is getting longer).<br>
So, the aperture itself is not changing (the opening cannot be set smaller fysically), but the effect of the same small aperture it the same as if you would be able to close it further.<br /><br />With most lenses, it is only written like f/4.5 - f/16 with a full opening, but in tele and in macro this can well be effective as f/16 - f/64 <br>
If you use these lenses with an older type of film-camera's that have (only) mechanic coupling, the aperture is getting a relative thing: with 'setting' the diafragma-ring on 'A' or by hand to '4.5' the aperture in tele/macro can be effective as f/16 and if you or the camere closes down to '16' this could be effective as f/32 . But these camera's don't know the real f/value. Doesn't matter though: there is less light and the film has some room to play with so in the end the effect on the print is neglected. <br>
With the newer analoge (MZ-7 / MZ-60 series) the correct calculation was done for the newer lenses just as would be done now for the digital camera's so that the effective apperture is calculated and written.<br />Older lenses don't always give the right information (why should they - in that time there was a mechanical coupling as well and the camera was doing a relative simple thing, besides that, the zoom was limited for example to 80-200 instead of 18-250 mm nowadays) and can lead to miscalculations that will be visible on digital camera's (and on slides by the way).</p>