Is lens testing at chart distance really an accurate measure?

Started 2 months ago | Discussions thread
AiryDiscus Senior Member • Posts: 2,160
Re: Is lens testing at chart distance really an accurate measure?
3

The typical chart size is between 1 and 2 meters wide. If you actually see someone test a 14mm lens on a full-frame camera that way, you might find it comical because the lens is only a few feet (maybe 2) from the chart.

The 30 or 50x focal length rules given in this thread for "infinity" are old and outdated. Modern lenses are very tightly engineered around their applications, a lot of wide angles are terrible close up like the fuji 16/1.4, but just fine focused afar.

It is a "correct" view that data for an object distance of a few ones of feet is only useful to your application at infinity if you drench it in assumptions that may or may not be invalid.

In general, with zoom lenses the more assumptions you make that are favorable to the lens, the further from reality you get.

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