Rodenstock 120mm 5.6 Apo Macro Sironar, optimum aperture is F11?

[Kodachrome25]

Hi there,

I have been shooting 4x5 macro work with a Nikkor 120mm 5.6 AM-ED lens for about a year, great lens. I have recently inherited a new condition Rodenstock 120mm 5.6 Apo Macro that might replace the Nikkor.

In reading about it's optimum working conditions, I see that the best apertures to use it at are rather shallow DOF settings of F8-F11. So a couple of questions, one would be is the AM Nikkor 120mm the same in terms of these wide settings being best and what on earth is the reason for this on the Rodenstock when if anything, more DOF would be a welcome thing?

Also, any opinions as to which might be best overall?

[Drew Wiley]

Hypothetical optimum sharpness aimed at something point blank doesn't equate to what is best when using lens movements, or, as you've already noted, dealing with depth of field issues. Most real subjects are not flat test targets. This is also related to cumulative image circle, which gets bigger the closer you get, and of course, gives you progressively less depth of field. Just test the darn thing relative to your own needs and how much enlargement the 4x5 is itself intended for.

[Bob Salomon]

Here are all of the tech sheets and the reason for 8 to 11.

http://www.rodenstock-photo.com/en/p...ironar-digital

[Drew Wiley]

All those specs are relative to digital backs, Bob, not full 4x5 film area, which is what he is referring to. Will the thing even cover at f/8 or f/11 without extreme
bellows extensions?

[Oren Grad]

All those specs are relative to digital backs, Bob, not full 4x5 film area, which is what he is referring to. Will the thing even cover at f/8 or f/11 without extreme bellows extensions?

Drew, the specification is...

201mm Image Circle at 1:5
277mm Image Circle at 1:1
374mm Image Circle at 2:1

...for "working stop 8-11".

[Kodachrome25]

Drew, the specification is...

201mm Image Circle at 1:5
277mm Image Circle at 1:1
374mm Image Circle at 2:1

...for "working stop 8-11".

This is correct, I have the non-digital one as spec'd at B&H, not the one Bob linked to.

Right off hand, the Rodenstock is a bit smaller than the AM Nikkor 120 so that might be one reason for me to favor it.

[Drew Wiley]

OK. Thanks, Oren. But that that f-stop specification is still relative to the specific demands of pro digital sensors, which are quite a bit fussier than actual film,
yet flatter. And the mere fact film is not as flat, and has quite different dynamics in terms of how light reacts to the surface, makes on think smaller stops might
give better results in real world FILM conditions! And one would be enlarging the shot less, of course, because it is bigger to begin with. Logical?

[Kodachrome25]

And one would be enlarging the shot less, of course, because it is bigger to begin with. Logical?

Yes, but I also try to make most of my 4x5 negatives with prints as large as 30x40 in mind, so the bigger is better theory works to a point. I try to go no smaller than 2 stops from minimum aperture to avoid significant diffraction effects but on some lenses have gone as small as one stop from minimum.

[Oren Grad]

OK. Thanks, Oren. But that that f-stop specification is still relative to the specific demands of pro digital sensors...

No, as K25 says, it's for the non-digital version of the lens. The specifications for the 120 Apo-Macro-Sironar Digital are completely different and entail a much smaller image circle, again for f/8-11. For all we know the two are identical or substantially similar optically, and the tighter specification for the digital version simply reflects a more stringent performance standard. But the numbers cited are for film.

[Bob Salomon]

All those specs are relative to digital backs, Bob, not full 4x5 film area, which is what he is referring to. Will the thing even cover at f/8 or f/11 without extreme
bellows extensions?

The Apo Macro Sironar Digital lenses are for digital use. The 120 and 180 Apo Macro Sironar lenses are analog. As were their predecessors, the 210 and 300 mm Makro Sironar lenses. The Apo Macro Sironar 120 and 180 cover 810 at 1:1.