Rodenstock Apo Sironar N or Apo Sironar S 150mm f/5.6

[John Layton]

Mark, thanx for the 210mm charts - although a bit fuzzy on my screen (slightly MTF-challenged). At any rate...given that these charts reference the lenses at their respective corrections for magnification...I'd be curious to see this same chart for all of these lenses focussed at infinity. Would also like to see the 210-N tested at 1:10, and then all three lenses at 1:5 magnification.

While I'm guessing that the S version might be a bit more forgiving over ranges other than its "ideal" 1:10, I'm also thinking that infinity performance might be a bit more even between these lenses (as magnification transition, from "ideal" towards infinity, would be less for the 210-N), at least given typical requirements of the 5x7 format in the landscape. As for close up work, I'm thinking that absolute edge performance specs become less and less meaningful, as less total available angle of acceptance is required as magnification increases. Make sense?

[Bernice Loui]

Fine print... MTF curves calculated or actual measured per each individual lens?


Bernice

[Sal Santamaura]

...I'd be curious to see this same chart for all of these lenses focussed at infinity...

Staying on the explicit topic of this thread, I own a 150mm Apo Sironar N, but not a 150mm Apo Sironar S, so can't provide any personal experience. However, five years ago there was discussion about 135mm, a focal length in which I do own both Rodenstock's Apo Sironar N and S versions. This was my input concerning a landscape comparison at around 50 feet, close enough to infinity for these purposes:

https://www.largeformatphotography.i...=1#post1164672

As for comparing MTF curves at differing magnifications, whether measured or computed, it doesn't provide useful information:

https://www.largeformatphotography.i...=1#post1241605