Differences between 150mm Apo Sironar S and N

[Jim Becia]

I am considering a 150mm lens - either an Apo Sironar S or N.

In another thread, mention was made that w/r/t 135mm Apo Sironars, the Apo Sironar N would be better suited for work at infinity focus, whereas the Apo Sironar S is better suited for closer focusing. This difference is attributable to the inherent lens design (optimization) differences between the two versions.

I searched other threads but did not find an answer to this as far as 150mm Sironars is concerned. I'm wondering what experience others might have had with actual use of these lenses and if the same comment holds true.

Most of my work is landscape photography and does not involve closeup work. However, I prefer a lens that is as sharp as possible at infinity. Does that preclude the Apo Sironar S, which by reputation is considered a better lens ? Perhaps the S would not be a "better" choice for my purposes if the N is designed for optimum infinity focusing.

Thanks in advance for your input any any experience with the lenses mentioned.

Dennis,

I have the 150S and it is incredibly sharp. It is a lens that Kerry Thalmann has on his "future classic" list. I have used it at all distances, and have never noticed any problems. Of course, this is just my opinion without doing any so called testing. But my images from the 150 Sironar S are tack sharp at all distances, including infinity. I sold my 150N to get the S and never regretted the move. For 4x5 it is a tremendous lens.

[Dan Fromm]

Your suspicion is unfounded. The magnifications specified are consistent with Rodenstock's design parameters, namely, the N series at 1:20 and S series at 1:10.

Thanks, Sal. Please point out what I missed in the brochures.

[Taija71A]

Please point out what I missed in the brochures.

MTF at ratio 0.05x (apo-sironar-n).
MTF at ratio 0.1x (apo-sironar-s).

Best regards, -Tim.

[Dan Fromm]

Thanks, Tim. For some reason I was blind to the charts' headings.

[Sal Santamaura]

Thanks, Tim...

Yes, thanks Tim for answering while I was away from the forum.

[richardman]

I make 20x24 prints a lot. Some even got printed 32x40", and these are scanned using a lowly V700. I have never found lack of sharpness being a Thing.

[Taija71A]

Thanks, Tim. For some reason I was blind to the charts' headings.

Yes, thanks Tim for answering while I was away from the forum.

No problem, Dan and Sal.
You are both more than welcome!

[DennisD]

Thanks to everyone who replied:
Alan Gales, Vinny, Jeroldharter, Dan Fromm, e, Sal Santamaura, Jim Becia, Taija71A, richardman.

I appreciate your comments, especially from those who have had hands on experience with the Sironar N & S versions.

The question of sharpness at infinity focus for the S is really seems to be a non issue, based on observations in this thread.

In comparing the specs, the image circle on the S is substantially larger. In addition, the amount of shift is almost 25% more on the S - great for architectural which I do frequently. Perhaps the greater covering and added flexibility (greater movement) of the S accounts for comments in the other thread that the S is the lens for close up work. Regardless, it's clearly an excellent choice for landscape and architectural.

Thanks to all for your help and advice.

Dennis

[Sal Santamaura]

Thanks to everyone who replied...

You're most welcome.

...The question of sharpness at infinity focus for the S is really seems to be a non issue, based on observations in this thread...

For most purposes, probably, but at least my samples of the 135 N and S are discernibly different, even in 1.75X prints.

...In comparing the specs, the image circle on the S is substantially larger. In addition, the amount of shift is almost 25% more on the S - great for architectural which I do frequently...

Image circle and available shift are two ways of stating the same characteristic. For architectural work, I agree that coverage (i.e. image circle) should be your predominant criterion when selecting between the two lenses.

...Perhaps the greater covering and added flexibility (greater movement) of the S accounts for comments in the other thread that the S is the lens for close up work...

Image circle is greater when working closer. At 1:1, it's twice the infinity value that Rodenstock specifies for each lens. This was no factor in my comment about the S being a better performer for closeup work. That observation was based on the fact that Rodenstock computed its N series for 1:20 and S series for 1:10.

[richardman]

Ah, if this is for architectural purpose, then the criteria would definitely be different. Get the most expensive lens you can buy then :-)