BirdForum is the net's largest birding community dedicated to wild birds and birding, and is absolutely FREE!

Register for an account to take part in lively discussions in the forum, post your pictures in the gallery and more.

Reply to thread

Message: <blockquote data-quote="henry link" data-source="post: 3290893" data-attributes="member: 6806">Konstantinos,There's always some form of distortion. If there's lower pincushion distortion that will cause angular magnification distortion to be higher. It's more of a design choice than a sign of quality. That said, I do find the design choice of the SF distortion to be odd. There is a wide swing from strong pincushion to very mild barrel over a space of about about 8º of apparent field. That almost certainly explains the reports of stronger "rolling ball" in the SF compared to the Swarovski SV, which has the same mustache distortion, but shifts the distortion over a narrower range from moderate pincushion to approximately zero rectilinear distortion.FWIW, the 8x42 HT follows the traditional Zeiss distortion pattern. It has approximately the same or the very same amount of straight pincushion as the 8x42 FL, which increases all the way to the field edge. It's about the right amount to correct angular magnification distortion so that the shapes of objects remain mostly unchanged from the center to the edge.Henry</blockquote>