Enlarging lenses as close-up taking lenses

[Dan Fromm]

CJ, please visit the LF Home Page and read the lens articles.

Your Repro-Claron was made after WW-II. Its cells should fit a modern #0 and the spacing should be right. The 210 will not cover 5x7 at infinity.

Schneider did not recommend using single cells of Repro Clarons or G-Clarons. That's a very strong hint. That said, many people practice lens abuse.

I'm astonished that the least expensive 300 you found is a 300/9 Nikkor-M.

Why are SF lenses so expensive? Not that common and there's a small but still growing soft focus cult.

[neil poulsen]

You can check with Schneider Optics tech support to verify, but I believe that your Componon-S 100mm lens will work in a Copal 0 shutter. Just remove the cells from the Componon-S barrel and screw them into the Copal 0 shutter.

Depending on the focal length of the lens for which the Copal 0 shutter is intended, you may need a correction factor in order to dial in a correct aperture. If the focal length is known, this is easy enough to calculate.

[cyberjunkie]

I am waiting for a few shutters, either expensive (Compur No. 0 and Compur Electronic No. 1), and cheaper (a couple of Polaroid/Prontor and Polaroid/Copal, either for ON shutter or IN shutter lens mounting).
I'll soon be able to experiment with all my enlarger and repro lenses, plus a G-Claron 240mm on barrel i've just got.
Thre are a few lenses that have the same or very similar focal length, i will try them all on cheap 120 film, and scan a few test pictures, to realize what's best and what's not, and eventually sell the optics i don't like.
I have already a small optical target, i think i've cut it from an old Kodak leaflet, long time ago. But it's very small, so if somebody knows about an optical resolution target avalable online, that would be nice. I would just need a .pdf of the target, and print it on an A4 paper sheet. It would be bigger, and good for pictures shot from a distance. Better if used with lenses that are optimized for infinity focus.
Coming back to enlarger and repro lenses, i would like to know if i'm right about enlarger lens use with LF cameras.
While the various Tominons for the Polaroid MP-4 have an optimal reproduction ratio (available from the macrophotography guide for the MP-4), as well as all the Clarons (for which Schneider provides PDF's with full specs, unfortunately in german language!), the enlarger lenses have an advised projection ratio, but no comments whatsover about their use as taking lenses.
As far as i understand there should be no difference in the way the light travels, if a lens is optimized for enlargements of about ten times the size of the film, the same lens should be good as a LF taking lens for tabletop/still life use. If we take the ratio of 1:10, and a 4x5" film , the lens should perform well with a subject of a width of about 1.2mt., if there is enough coverage, of course.
Following the same rule, some Apo lenses optimized for wall projection on very big enlarging papers, should perform better with infinity, or close-to-infinity focusing.
Am i right?
Or maybe i'm just overlooking something... i'm not very experienced.
I've just used shorter enlarger lenses on bellows, with 35mm cameras, but never exceeding 1:1 macros, because i had a reversed 25mm prime for 16mm video camera, or a Canon lens with microscope thread, that were a better choice for extreme macros.
Of course the reproduction ratio means totally different things if different film formats are used. A 1:2 on 35mm means to fill the frame with a big dragonfly, with 4x5" means protraying a small vase with a flower!

I will do my tests, but would be very grateful if somebody tells me if i'm right or wrong

have fun


CJ

[Dan Fromm]

The magnifications recommended for MP-4 Tominon macro lenses in Polaroid literature are simply the magnifications they'll give on a standard (not -XL) MP-4. These are attainable, not the best ... I found the 17 mm to be best at around 20:1, the 35 variable from example to example and best between 10:1 to 20:1, the 50 around 9:1 to 12:1. the 75 best around 4:1, and the 135 simply horrible. At its sharpest, each focal length is sharper than the next longer one at its sharpest.

If you must test lenses above 1:1, buy a USAF 1951 on glass target from Edmund Industrial Optics. The inexpensive one goes up to 228 lp/mm.

I thought I told you that Schneider says Componons are best for enlarging from 8x to 12x, Comparons from 2x to 6x. That corresponds to taking at 1:8 - 1:12 and 1:2 - 1:6 facing normally, 8:1 to 12:1 and 2:1 - 6:1 reversed. They also say that each is better in its good range than the other.

Scanning film before measuring image quality is stupid. The scan can't be better than the raw film. Shoot your targets, examine the negatives at high magnification. Use a microscope, 50x should be enough.

I understand that you're not secure. We're none of us as secure as we'd like to be.

For the nth time, buy and read the Lefkowitz book I think I recommended earlier in this thread before you ask more questions or take a single picture. You'll get a better education from it than from short answers to badly posed questions.

[cyberjunkie]

The magnifications recommended for MP-4 Tominon macro lenses in Polaroid literature are simply the magnifications they'll give on a standard (not -XL) MP-4. These are attainable, not the best ... I found the 17 mm to be best at around 20:1, the 35 variable from example to example and best between 10:1 to 20:1, the 50 around 9:1 to 12:1. the 75 best around 4:1, and the 135 simply horrible. At its sharpest, each focal length is sharper than the next longer one at its sharpest.

Ok.
Thanks for advice.
It's more or less the magnification ratios i was guessing for those lenses.
The nice thing is that, having the same thread in common, and being front mounted on the shutter, they're easily usable with other cameras/film formats.

If you must test lenses above 1:1, buy a USAF 1951 on glass target from Edmund Industrial Optics. The inexpensive one goes up to 228 lp/mm.

I thought I told you that Schneider says Componons are best for enlarging from 8x to 12x, Comparons from 2x to 6x. That corresponds to taking at 1:8 - 1:12 and 1:2 - 1:6 facing normally, 8:1 to 12:1 and 2:1 - 6:1 reversed. They also say that each is better in its good range than the other.

I will use the resolution target i have already, having a target shipped from abroad would cost too much, and i'm not willing to spend too much money on tests that have too much variables to be truly significant. Even MTF lens tests made by magazines/Internet sites, with expensive hardware, are often criticized for being too little scientific or for overlooking something important.
In the end, if you are an amateur and practice LF photography for your own pleasure, it's you who pay the money for lenses, and it's you who must be satisfied about them
Unfortunately testing a new lens on the field takes time and some expensive film, so doing some kind of homemade test could be of some help, but it has to be seen if it's more on a psicological level than on a practical one.

I did remember your previous answer about suggested reproduction ratios for Componons and Comparons. I was simply asking for a confirmation. The simple fact that it's not important if the light is traveling in one direction or the other, made me consider that in practice the same reproduction ratio means different things, if different film formats are used.
With a 35mm, a 1:6 ratio is a semi-macro (or, more correctly, a close-up), while the same ratio on 10x12cm. film, could mean a table-top picture.
I love shooting still life compositions, and i was striken by the idea that an enlarger lens for 4x5" printing could become a nice taking lens for that kind of pictures.
So i was asking if the practice confirms it, and if some forum users have enjoyed that kind of lenses as still life optics .

Scanning film before measuring image quality is stupid. The scan can't be better than the raw film. Shoot your targets, examine the negatives at high magnification. Use a microscope, 50x should be enough.
For the nth time, buy and read the Lefkowitz book I think I recommended earlier in this thread before you ask more questions or take a single picture. You'll get a better education from it than from short answers to badly posed questions.

Then lots of people are stupid.
The Internet is full of pages where any kind of different theories about lenses/scanners/films are supposedly demonstrated by ... guess what, film scans!
I have seen scans made with cheap flatbed scanners, enlarged to a point where the film grain was evident, without too much image degradation. So i suppose that something sgnificant can be gotten out of it.
I'm not saying that a scan, whichever the machine used for scanning, could be better than the film itself!
The real thing is the real thing, and a digital representation of the original is not on par with it.
But if you want to do a quick evaluation of a new lens, and you have no microscope at home, performing a quick scan and doing a simple on-screen enlargement of the file, could be used as a quick-and-dirty test, with no additional tools required.
Maybe i'm not sophisticated enough, after all i came to this forum to learn, not because i was already an expert!

I understand your advice about the Lefkovitz book, but i live on the other side of the Atlantic, and not all books are available. As soon as i find it without having to pay for the shipment from USA, i will definitely buy it. I love photographic theory, and books that go in depth, so i'm sure that i will enjoy it.
About "badly posed questions"... maybe it has more to do with writing in a foreign language, than with any other thing. After all nothing i have written was wrong or meaningless. I was just asking for a confirmation about what i understood, maybe in a way that's just a little bit naive. Nothing more.


have fun

CJ

[Dan Fromm]

Have you looked for the book?

http://www.alibris.com/booksearch?qw...isting*buyused

http://www.amazon.com/gp/offer-listi...condition=used and look at shipping rates. If you can't afford $US 25 for the book you can't afford to take pictures.

The targets you can download don't have the fine detail needed to assess how well a lens performs in the close-up (magnification 1:10 - 1:1) and macro (magnification > 1:1) ranges. Tests with the wrong target won't help you make decisions.

A simple resolution test (actually a series) will find the range of magnifications at which the lens is good enough to use. Implicit in that is whether the lens is good enough to use at all. I own some lenses that aren't good enough to use.

[cyberjunkie]

Thanks Dan!
I was not aware that used books could be purchased so cheap, using Amazon search engine.
The book is on its way to Italy, i hope to get it soon.

But another advice i was given proved to be misleading:
my old Repro-Claron 210mm, in barrel mount (with slot-in variable diaphragm for extra-small f stops), couldn't be fitted in a No. 0 shutter, as per Schneider literature.
To put it simple, it couldn't be fitted in a No. 1 either, cause the thread diameter is too big. If i correctly remember, my caliper gave me a measure of around 43mm, including thread. So it's too small for a No. 3 and too big for a No. 1.
Looking at the two (identical) cells i had just removed, in dim light, i thought that the thread was around the smaller internal lens. So without looking further i promptly tried to screw the cell on a Compur No. 0 i had on the table. It didn't fit! The thread was around the bigger (outer) lens. So it's evident, as i checked later, that the Repro-Claron cells used for barrel mount are not the same ones, mechanically, as the shutter-mounted ones. In fact, looking at the pdf about Repro-Claron lenses produced after 1972, available from Schneider web site, you can easily see that the barrel-mounted lenses have no indication about which barrel is used. The same lenses in "verschluss" (shutter) have all the infos about shutter size and threads diameters. Other pdf's about different (mostly newer) Schneider lenses have both references about barrel No. and shutter No. and i could personally check that a lens in a No. 0 barrel would easily fit in a No. 0 shutter without any need for shims to correctly space the cells. I just did it with my Componon-S 100mm, early eighties i think, and a 240mm G-Claron; both were easily fitted on a No. 0 Synchro-Compur and a No. 1 Compur Electronic, keeping the same dimensions they had when they were fitted on their original No. 0 and No. 1 barrels. Of course this is confirmed by the relevant pdf's.
It's very nice to have the documentation of old Schneider lenses available online.
On the other hand, Rodenstock barrel lenses have no neither online documentation nor standard barrel mounts, as far as i know. Please correct me if i'm wrong.

Coming back to my Repro-Claron, the cheapest solution that comes to my mind is to have two custom-made adapter rings that would keep the correct lens spacing.
Unfortunately a No. 1 shutter seems to be a little too tight, because the rear thread is more or less the same diameter of the internal element. Maybe the right ring/spacer would keep the element aat distance that would prevent vignetting, but i would feel more at ease with a bigger shutter. A standard No. 3 shutter would be too expensive (i don't own one), so maybe a better solution could be found in some oddball shutter, like an old No. 2, or one of those medium size US-made shutters that are easily found on Ebay, maybe with an attached Kodak or Wollensak press lens.
Those shutters can be quite difficult to find in Europe, only those mounted on Graflex press cameras are easier to find. So i don't know much about them, and i would be very happy if somebody helps me out, with a few suggestions about a cheap and viable option. Some of those shutters are already very expensive on the bay, expecially the bigger ones: i have seen Ilex No. 5 shutters, in barely decent condition, sold for more than 200 hundred bucks!

have fun

CJ