Schneider-Kreutznach lens parameters

[JKT]

I seem to recall seeing explanations for Schneider-Kreutznach lens parameters somewhere, but I can't find them now. Anybody have such a document they could share?

f'eff is focal length, but what are the others? SF & S'F' are likely distances to focal point, but from where? From nodal points or elsewhere?

HH' is likely distance between nodal points, but does negative value mean they are crossed or the opposite?

That leaves SEP, S'AP and Sigma d. Are the first possibly pupil distances? If so, from where? The last one is a total mystery.

[RobertOToole]

I seem to recall seeing explanations for Schneider-Kreutznach lens parameters somewhere, but I can't find them now. Anybody have such a document they could share?

f'eff is focal length, but what are the others? SF & S'F' are likely distances to focal point, but from where? From nodal points or elsewhere?

HH' is likely distance between nodal points, but does negative value mean they are crossed or the opposite?

That leaves SEP, S'AP and Sigma d. Are the first possibly pupil distances? If so, from where? The last one is a total mystery.

That is on my site a few places but I can post it here, give me a minute to find it.

Robert

[RobertOToole]

3 different versions from SK that I have posted before.

Best,

Robert

[Lou Jost]

Aha! Now the negative beta makes sense. The image is inverted.

[JKT]

Thanks Robert! I should have guessed they were yours - much of the useful stuff is.

[RobertOToole]

Thanks Robert! I should have guessed they were yours - much of the useful stuff is.

Glad to help. Keep it in mind that over the last couple of months I've been able to get answers from the CEO of SK somehow, not sure if I got lucky getting his email or the CEO answers technical questions at SK now? Anyway if you have some tech question, I can have this guy answer or he can email Germany for the answer. The guy has been a lens designer for something like 30+ years.