300mm APO Sironar-N versus 300mm Sironar-S

[Bob Salomon]

Because the difference will also be on the print - unless he has an awful enlarging lens and does not use a glass carrier. ANY DIFFERENCE VISIBLE ON THE NEG/SLIDE IS EXPECTED TO BE ON THE PRINT.

[Donald Hutton]

Bob

You are wrong. Plain and simple. Not only that, but in being so, you are presenting incorrect information to someone who asked a question relating to a product supported by you organisation. AT 2.5 magnification, there will never be any difference visible on the negative - NEVER. Therefore, IT WILL NOT BE VISIBLE ON THE PRINT. I am not attempting to get into a shouting match with anyone, but it really annoys me when someone who's very presence on this forum is entirely commercial offers incorrect and obviously wrong information.

Try it - look at a negative with a 2.5 magnification loupe - it's not nearly powerful enough to be splitting hairs with two very good modern lenses. You may discern some tiny differences at about 15X.

[Bob Salomon]

Tell me Don,

Have you actually used an Apo Sironar S and compared it to the Apo Sironar N or are you talking from a complete lack of inexperience about the actual lens?

[Donald Hutton]

I have actually extensively tested quite a few modern 150mm lenses, including an APO Sironar-S and an APO Sironar-N. I shot a real world target from the same location as well as a test chart layout (all on Tmax100, identically processed with a Jobo). I then examined the negatives at 40X under a microscope, with a 22X loupe and 4X loupe. I then made an 8X20 print from each (a central crop edge to edge - a 4X magnification print - I did 8X20 to save a little on paper). A 4X magnification print examined with a loupe reveals no differences. In fact on seven of the nine lenses I tested, there was no difference on the print. With a 22X loupe on the negatives, quite a bit of difference is revealed. With the microscope, it's all pretty clear.

So in answer to your question, I have actually used an APO Sironar-S and an APO Sironar-N lens and compared the results from the two quite objectively. While I have not actually used a 300 APO Sironar-S nor N, I am certain that what I learned from my tests with 150mm lenses can very safely be extrapolated to 8X10 film and 300mm lenses. So I am "talking" from some experience.

Have you ever personally tested them side by side? Or do we need to sift through a lot of marketing conjecture?

[Bob Salomon]

Yes we regularly shoot side by side comparisons and the S has better contrast, better tonal quality, better color saturation, reaches optimal aperture sooner - one stop down - and held it for a longer range. Better bookah and more pleasing toniality. Also much better edge definition when doing movements due to the larger circle.

Of course I don't shoot test charts. These were three dimensional objects from tabletop range to infinity.

We frequently shoot lenses side by side when they are returned to us for service or when we are coupling a lens to a Linhof rangefinder.

[Donald Hutton]

Bob

Perhaps "real world target" was misleading - is real world "subject" a bit clearer for you - i.e. 3-dimensional (in fact the view from outside my front door of the house across the road)? At extremes, I am sure the "S" lenses are a little better, but that is not actually what this thread is about. Nor is this thread about whether or not the "S" lenses reach optimal aperture sooner or later. "Bokeh" (I hope that is the correct spelling) is typically not a factor for most large format shooters either (obviously for portrait and product shooters it is) - in fact most landscape and architectural shooters spend a lot of time making sure that everything is in focus. I will be very happy to provide detailed scans from the two shots to anyone interested. Are you prepared to do the same (especially if you have all this "material" at your disposal, as well as far greater resources and a much greater financial interest in doing so)?

At a paltry 2.5X magnification , not you nor anyone on this planet will be able to tell two prints apart from an "S" and an "N".

[Bob Salomon]

Be happy to send you a scan of comparisons done by the factory. We would never share images done by someone else or with someone elses lens.

Just let me know where you want it emailed to.

[Donald Hutton]

donald_hutton@ameritech.net

[J. P. Mose]

Well I didn't mean to start WWIII!

Bob...out of curiousity...how do rate the 300mm APO Sironar N against lenses from the other big three companies? Does the Sironar N even compare with a Symmar S or APO Symmar?

Oh yes...by all means...please e-mail me with the same comparisons you are sending Don:

j.p.mose@lmco.com

[Brian Vuillemenot]

I'm interested in seeing these comparisons also, so I can decide for myself if my Apo-Sironar S was worth the extra money. Can we post them up to this thread?