Posted: Sat Oct 24, 2020 12:44 pm Post subject: Re: O.Pen lenses in FF = AGFA ISO? |
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Gerald wrote:
papasito wrote: |
In the theory, the lenses for O. Pen 24 x 18 system, should produce a 24 x 24 mm square image in FF cams, more bigger than the APS-C size, so useful |
In fact, the lens should be able to produce an image circle with a diameter equal to the diagonal of an 18 x 24 mm rectangle, ie 30 mm. Therefore, we can say that a 30mm diameter image circle is guaranteed to cover a 21.2 x 21.2 mm square, but not a 24 x 24 mm square.
In practice, lenses are usually designed for an image circle larger than what is strictly necessary, so it is possible that a lens for Olympus Pen can produce an image of 24 x 24 mm with good resolution and little vignetting in the corners. _________________ If raindrops were perfect lenses, the rainbow did not exist. |