PDA

View Full Version : Nikkor AM 120mm/5.6 ED Macro/Rodenstock 120 macro



Don Boyd
20-Sep-2003, 14:25
I am interested in doing wildflower closeups with my Shen Hao 4x5 and am considering both the Nikkor AM 120mm/5.6 ED Macro or the Rodenstock APO Macro 120. Can either one be used for near far (infinity) as well? I am new to both LF and to LF Macro but have shot some with the Pentax 6x7. I assume that the depth of field with these lenses is greater than a non-macro 120 is that correct? Anything special I need to keep in mind in shooting macros with either of these lenses? Thanks

Jean-Marie Solichon
20-Sep-2003, 14:47
"I assume that the depth of field with these lenses is greater than a non-macro 120 is that correct" No, depth of field will be the same. The macro lenses will be better corrected at 1:1 and give better resolution. I'm not sure but I guess both will not cover 4x5 at infinity and may be not very sharp as well. Jean-Marie

Arne Croell
20-Sep-2003, 15:04
Don, depth of field is only a function of aperture and magnification, not of the lens type. The specialized macro lenses give you better correction of lens aberrations at 1:1 compared to a lens optimized for infinity or 1:20. Of course that means that the 2 lenses you mention would not be optimal at infinity - in addition, the Nikon does not cover 4x5 at infinity, and the Rodenstock just barely so. If you want a lens for more general use, look for one that is well corrected also at close up range, e.g. the new Apo-Symmar L range. Schneider claims they are useable down to 1:3 without much of a loss in quality. A cheaper alternative is to use a (used) process lens; they are usually corrected for 1:1 but work well at infinity, too. The shortest you could use, covering 4x5 at infinity would be a 150mm G-Claron or a similar one (Rodenstock Gerogon, Docter Germinar W). You will need to optimize all your camera movements for macro on LF: depth of field is rather small.... And you have to calculate the bellows factor for exposure, no TTL metering here (except you use one of those Sinar measuring probes).

Don Boyd
20-Sep-2003, 15:17
Jean-Marie and Arne, thanks for your responses. I was hoping to be able to use a macro lens at infinity as a bonus. But, my primary concern would be their increased resolution at macro and distances out to say 3 or 4 feet.

Any readers of this site use these lenses for wildflower/lichen/nature geometrics close-up work?

Ernest Purdum
20-Sep-2003, 15:24
The Nikkor lens is a true macro type and is optimized for close work. I would expect the same to be true of the Rodenstock. Some lenses intended for close work do perform well at distance when stopped down to small aperures. One which has an excellent reputation in this regard is the Schneider G-Claron. Although discontiued, it is easy to find exampl;es in optically mint condition. The 150mm version would, I think, be a good choice for you if your camera is one with 360mm extension. (I'm not sure if all Shen Hao's go out this far, but I know some do.)

Depth of field is strictly a function of distance and aperture. You can, of course, adjust the plane of whatever depth of field you have by the use of your tilts and swings.

I think the major problem in wildflower photography is subject movement. You might want to bring along items to use as wind baffles, in addition to reflectors, if you are using natural light. The windshield covers that have a spring around the edge and fold into a circle might be handy, as would several spring clamps.

Ernest Purdum
20-Sep-2003, 17:15
Armin, Wow! You ask tough questions. I'll try, but a complete answer would probably be a subject for a doctoral dissertation. Regarding your Nikon macro. All lens design is compromise, trading off aperture, coverage, cost, weight and other factors to arrive at a design optimized for whatever the designer expects the user will do with it. In the case of your Nikon, he, or his computer, knew that it would be used for distance work as well as close up, so provided a compromise. Your posting is evidence that his results were very good.

Regarding the Apo Ronars,the answer here is easier. These, like the Apo Artars several other process objectives and the Kodak f7.7 lenses, are classic dialytes, a type recognized for very many years as being remarkably tolerant of variations in the subject/image ratio. To obtain this virtue, though, you had to be satisfied with a rather small aperture, usually about f9 for focusing and f22 for exposure, as well as fairly narrow coverage.

Arne Croell
21-Sep-2003, 03:51
Good point, Armin. Let me start saying that I do not have personal experience with either the AM-ED Nikkor or the Rodenstock (or Schneider) equivalents, but that I do have experience with process lenses, and they can certainly be used to infinity (with some stopping down) with very good results. My assumption was based on the following: the use of the term "Macro" as applied to a specialized lens seems to be more restricted in LF than in, say, 35mm. Note that for instance the Apo-Sironar S series seems to be optimized for 1:10 (thats what all the Rodenstock MTF graphs are for), which would already be considered borderline "Macro" in 35mm. The lenses in question here are all optimzed for 1:1 AND the manufacturers state that the useable magnification ratio is from 1:3 to 3:1 or 1:4 to 4:1. Note that the recommendations for process lenses are a bit more lenient (if not downright to infinity, its at least 1:5 to 5:1, e.g. G-Claron). From these numbers I inferred that the lenses will not deliver the very high quality they were made for outside that range - or, in other words, that an Apo-Macro-Sironar at infinity would not be better than a regular Apo-Sironar at 1:1. They would most probably still be useable especially stopped down.

Bob Salomon - HP Marketing
21-Sep-2003, 06:28
"Why does then my Nikon micro nikkor 60mm perform even better then my 50mm primlens at infinity?"

Floatingelements. Something that is not used in large format lenses.

And for those process lenses they will perform at infinity but not as well as a lens made for use from 1:10 or 1:20 to infinity. But yes it will deliver an image that someone who is most concerned about price or weight or size may be satisfied with.

And at close distances of 3 dimensional objects - say flowers- that process lens will also not be as good as the macro lens.

As for possibly improving at long distances when stopped way down - not really. Stopping way down causes diffraction.

Arne Croell
21-Sep-2003, 13:22
Armin, I am looking forward to your report. I looked up the Apo-Macro-Sironar specs and interestingly, of the three dedicated macro lenses (the others being the AM ED Nikkor and the Macro-Symmar HM) this one is not symmetric. Also the spec for best performance is 2:1 to 1:5, which means its tweaked a little closer to the infinity side than a symmetric lens.

Don Boyd
21-Sep-2003, 14:54
Armin, I also will be interested to see your findings.

Bob Salomon - HP Marketing
6-Oct-2003, 10:46
"I think the Macro will be the loser on thad Part! I let you know!"

Armin,

There is no doubt or question. The Apo Macro Sironar and the Apo Macro Sironar Digital lenses are not designed for other then macro work with 3 dimensional objects, nor will they perform as well as a general purpose optic at scales beyond 1:5.

And a general purpose optic that performs better at scales beyond 1:5 will not equal the Apo Macro Sironar and the Apo Macro Sironar Digital lenses with 3 dimensional objects at scales from 1:5 and larger.

Bob Salomon - HP Marketing
6-Oct-2003, 17:50
"at f 32 thad the Rodenstock macro could be the winner"

Except you will be in diffraction.

Bob Salomon - HP Marketing
6-Oct-2003, 17:51
"ymmar S"

And try it compared to an Apo Sironar S. That way you are comparing two current designs.