Lens for studio use

[aduncanson]

There is absolutely nothing wrong with using a process lens for 3D objects. Macro lenses are not optimized for 3D objects. (What would that mean? if optimized for concave subjects, what if the subject is convex?) A flat field is absolutely essential for a process lens, slightly less so for a macro lens. The designer may simply not emphasize flatness of field, quite so much, in trading off design choices for a macro lens and thereby deliver improvements in some other area. (Although from experience with an Artar, it would be hard to imagine what other area.)

A highly affordable option for the range you are looking for is an enlarging lens mounted in a shutter. One often sees a 135mm Componon S mounted in a shutter. Some say that a Comparon actually is better optimized for those modest reproduction ratios.

[aduncanson]

Dan - This is one of your areas of expertise. Could you please elaborate ?.

While I'm not Dan, I will suggest an explanation.

Imagine that a taking lens is optimized for 1:30 and you are shooting at 1:2. If you reverse the taking lens it is now optimized for 30:1.

1:30 is closer to 1:2 than is 30:1 so the reversed lens is operating further from its optimal magnification.

[Dan Fromm]

Ken, the idea's simple. A lens can be optimized for only one magnification (or, different words, pair of conjugates). Possible magnifications come down to 1:1 (life size) and everything else. In the case of everything else, the lens can be set up for < 1:1 (large subject, small image) or > 1:1 (small subject, large image). If we reverse a lens set up for < 1:1 and tben use it to shoot at < 1:1, we're not making good use of its optimizations.

I'm relieved that Ernest and I agree. But there are reversed Tessar type lenses (cemented doublet in front of the diaphragm, singlets behind) that were made for shooting at < 1:1. His discussion of MP-4 Tominons, some of which are reversed Tessars, isn't as clear as it could be.

Robot, that process lenses are designed to give good field flatness at their recommended working apertures is true. So are all taking lenses. Curvature of field is an aberration that lens designers usually try to eliminate. The big exception that I know of is special purpose lenses made for photographing images on a CRT. I gather that they're tuned to the CRT they're to be used with.

Robot, I also don't understand why people keep repeating the canard that one shouldn't use a process lens on 3-D subjects. I use process lenses -- Apo-Nikkors, Apo-Ronar (only 1), Apo-Saphirs, G-Clarons, GRIIs -- and lenses taken from repro cameras and am not aware that they prevent me from getting good results. My lousy technique is another matter, but it isn't the lenses' fault.

I've asked a number of the idiots, sorry, people who don't pay attention to what they say, who repeat this old-wives tale how to deal with subjects whose shape doesn't match the lens' surface (not a plane) of best focus. Not all curved surfaces are alike. I've yet to get an answer, except the news that I'm an idiot. This isn't news or a good answer, alas.

This discussion reminds me of the physicist joke whose punch line is "Assume a spherical perfectly elastic horse."

[Armin Seeholzer]

Hi

The 210mm F5.6 Rodenstock APO-Sironar-S is optimised up to 1:4 to infinity if I remember correctly I'm not at home so can't look in to the specs!
I used mine up to 1:2 with very good results!!!

Its deadly sharp, Armin

[Ken Lee]

Dan and Alan -

The following is a quote from the on-line Rodenstock "brochure" for their APO-Macro-Sironar. Are they exaggerating or misleading us ? I ask sincerely - They wouldn't be the first sales team to stretch or embellish the truth.

Apo-Macro-Sironar
"In the close-up range, at scales of around 1 : 1, the quality of lenses optimized for larger distances falls visibly from the usual standard of performance. Here the Apo-Macro-Sironar lenses come into their own for imaging scales of 1 : 5 and greater.

Incidentally, imaging scales of 1 : 5 or larger are required even in conventional table-top photography or studio photography (e.g. pack shots): for example, 1 : 3 at a film size of 4 x 5 in. means the full format image reproduction of an object of approximately 30 x 40 cm (12 x 15 in.) in size.

The Apo-Macro-Sironar offers excellent imaging quality in conjunction with the wide freedom of movement required for perspective corrections of large-format photography. Due to the image circle diameter increasing with the reproduction scale becoming larger, this lens allows even more freedom of movement than lenses designed for greater distances.

The Apo-Macro-Sironar provides exceptional results without any color fringes at a scale range from 1 : 5 to 2 : 1 without any need to adjust the lens individually. The focal lengths of 120 mm and 180 mm allow work with most cameras without any extra monorail extension even at a scale of 2 : 1."

[Ken Lee]

"I use process lenses -- Apo-Nikkors, Apo-Ronar (only 1), Apo-Saphirs, G-Clarons, GRIIs -- and lenses taken from repro cameras and am not aware that they prevent me from getting good results".

I have used APO-Nikkors for 3-d subjects (flowers), and have gotten fine results. I admit it.

Perhaps the admonition against using process lenses for 3-dimensional subjects, is just a canard, as you suggest. I have depended on the opinion of others in this area.

On the other hand, I have found that using a f/5.6 lens (like the 210mm Macro Sironar N and 150mm Sironar S), makes it much easier to see what's going on, compared to f/9. But like most of us, I'm not working in a studio. I have no lights: just a window and a piece of black cloth, propped up on some books. It's also nice to be able to shoot wider open, if we want a more shallow depth of field.

[aduncanson]

Ken,

I suspect that what they are saying reflects that the actual optimization for that lens is at some intermediate ratio near 1:1.6 (the geometric mean of the two limiting ratios) and that it performs "acceptably" from 1:5 to 2:1. That may be true, but for the reasons that Dan gave, I suspect that the performance beyond 1:1 would improve if the lens were reversed.

Alan

[Robot]

Thanks for everyone's help thus far. My trolling on ebay is getting to be a bit excessive though with all the different leads.

The article on Macro lenses was a good read. However, that leads me to believe that macro would not be ideal for my purposes as I don't think I will ever be shooting 1:1 or greater magnifications (small subject/large image). Rather, the subject size I am working with will always be reduced to film size. Ex. 9" head reduced to 2.5" on 4x5" film.

Does anyone have published charts comparing conjugate ratios for different lenses?

[Ken Lee]

Ken,

I suspect that what they are saying reflects that the actual optimization for that lens is at some intermediate ratio near 1:1.6 (the geometric mean of the two limiting ratios) and that it performs "acceptably" from 1:5 to 2:1. That may be true, but for the reasons that Dan gave, I suspect that the performance beyond 1:1 would improve if the lens were reversed.

Alan

Excellent - Thanks again !

[Ken Lee]

The article on Macro lenses was a good read. However, that leads me to believe that macro would not be ideal for my purposes as I don't think I will ever be shooting 1:1 or greater magnifications (small subject/large image). Rather, the subject size I am working with will always be reduced to film size. Ex. 9" head reduced to 2.5" on 4x5" film.

What distracted me, is that you asked for top performance at close range - "sharp like a bullet hole through a stab wound through a bee sting" - but want neither a macro, nor a strictly general-purpose "landscape" lens. You want to make 10x enlargements, too.

I'm not an expert, but I've never heard of lenses that are optimized for that "intermediate" distance. So it seems to me that any of the 210mm lenses you've mentioned should work fine.