Is lens testing at chart distance really an accurate measure?

Started 2 months ago | Discussions thread
AiryDiscus Senior Member • Posts: 2,160
Re: exhaustive testing becomes -- exhaustive

Bernard Delley wrote:

Optical bench apparatus have a collimated test target. Infinity testing is the standard. For finite distance testing one needs a different collimator for each distance.

Not really.  It wouldn't be a "collimator," either.  Trioptics MTF benches physically place a crossed pair of slits at the object distance.  Optikos uses a projection with variable focus.  As long as the projector has sufficiently low wavefront error over the range of distances it can project, it is a nonissue.

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