Is lens testing at chart distance really an accurate measure?

Started 3 months ago | Discussions thread
Erik Kaffehr
Erik Kaffehr Veteran Member • Posts: 4,762
Re: Is lens testing at chart distance really an accurate measure?
1

AiryDiscus wrote:

Erik Kaffehr wrote:

Looking at the same lenses at 1.2 m, a different picture arises:

Here the Zeiss CF 3.5/100 has astigmatism while the 2.2/100 HC maintains sharpness.

That's definitely third order coma. It's field linear and astigmatism is quadratic.

Thanks for the correction! Learning something new each day. Lots of things learn so I hope for a long life.

Best regards

Erik

-- hide signature --

Erik Kaffehr
Website: http://echophoto.dnsalias.net
Magic uses to disappear in controlled experiments…
Gallery: http://echophoto.smugmug.com
Articles: http://echophoto.dnsalias.net/ekr/index.php/photoarticles

Post (hide subjects) Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow