Fun With Rodenstock

[StephanN]

Following up Andrea's suggestion here (https://www.ultravio...432-minimalism/), I've decided to try out my Rodenstock for UV. A few of the photos are already presented in this thread, owing to the fact that they contain insects: https://www.ultravio...cts-with-flash/

 

The lens is a Rodenstock XR-Heligon 100mm f/1.5, and it came in a M42-version. I glued a filter-ring to the front, as I wasn't sure about the thread, having tried out screwing in a few of my adapters. It is a tricky beast in therms of focussing, as the only way of finding focus is rocking back and forth, and trying to take focus-shift into account. Therefore, I won't claim that focus is always exactly where I wanted it to be

 

First there are three comparison shots with this lens in VIS, UV and IR (700 nm), just to get a first idea. It looks like an Iris-Barbata-Media, but I'm not sure [Edit]Anemone blanda, "Blue Shade", Frühlingsanemone (thanks, Birna) [/Edit]. [Edit]Thanks to Andrea for the help in identifying some of the others [/Edit]

 

There are plenty of signs with the names, but sometimes there are more signs than flowers or more flowers than signs

 

 

 

 

Next, some comparison shots, where the VIS one was taken with my mobile phone, and I think that I located the correct signs

 

Crocus Vernus Hybride "Flower Record", Frühlingskrokus:

 

 

 

 

Primula elatior Hill., Wiesenschlüsselblume:

 

 

 

 

Tulipa ???, Tulpe:

 

 

 

 

And finally, just a few odd ones, to show how the out-of-focus bits are rendered :

 

Galanthus nivalis, Gewöhnliches Schneeglöckcchen:

 

 

Tussilago farfara, Huflattich:

 

 

Scilla chionodoxa "Glory of the snow", Sternhyazinthen:

 

 

 

Anemone blanda, "Blue Shade", Frühlingsanemone:

 

 

 

So, the conclusion is that this lens is usable for UV, at least to some extent; I guess that since most flowers will show some UV-signature even very close to VIS, it'll be fine for that. However, how far it does reach into UV, I really couldn't say.

[Stefano]

I like the soft look the lens gives.

[nfoto]

Nice examples. The 100/1.5 is probably less easy to use than the f/1.6 model as the former has much shorter back focal distance.

 

The first sequence is of an Anemone species, possibly A. blanda.

[Andrea B.]

Stephan, wow, *very* cool !!!!! That XR does indeed pass some UV and IR. And of course the same "dreamy" look appears in UV and IR as does in Visible light. The backgrounds are fascinating. Some of the results look like paintings.

 

The UV signatures for the flowers I know are certainly correct.

Below I've added a couple of links.

 

Thank you so much for setting up and making this experiment for us.

 

More flower notes:

Anemone blanda -- has both a light UV signature and a dark UV-signature.

Your example is the light version.

 

The yellow flower after the Wiesenschlüsselblume is a kind of Tulip (genus Tulipa) (G. Tulpe).

 

The first of the "odd ones" is Snowdrop (genus Galanthus) (G. Schneeglöckchen).

And that is a lovely UV photograph of the Snowdrops.

Galanthus

 

The third of the "odd ones" is Glory-of-the-Snow (genus Chionodoxa).

I could not find a German name for this one which seemed correct.

Glory-of-the-Snow

[Stefano]

Primulas are a flower you can find on lawns here, although not as common as daisies and dandelions. We have just one plant in our garden. What's odd is that, rarely, you can find a purple/magenta version, in the wild. I just found two today near our home. I don't know why this happens. I know cultivars can have a lot of different colors, but those flowers are completely wild, they just "spawn" different.

[Andrea B.]

Sometimes the flowers we see in the wild are actually "escapes" from somebody's garden. However, there are certainly some wild Primula which are pink.

Example: http://www.wildflowe...flower=Primro (scroll down)

 

Reference:

Spohn, Aichele, Golte-Bechtle, Spohn (2011) Che Fiore è Questo? Primula farinosa, pg 48. www.editorefrancomuzzio.it.

Primula farinosa is pink (dal fucsia al rosa pallido).

[Stefano]

They look similar. I wonder if it's a recessive gene, or some kind of random mutation.

[StephanN]

The UV signatures for the flowers I know are certainly correct.

Below I've added a couple of links.

 

Thanks, Andrea, I've updated the initial post. Do you think the last one could be an anemone like the very first flower? For me, as botanical illiterate, even with the sign in the Botanical Gardens it's not always cearl which sign belongs to which flower

[nfoto]

I was tempted to have a look at my various Rodenstocks of 100mm focal length. The f/1.5 needs some arrangement to make it mountable, however the f/1.6 already was already adapted to a focusing helicoid, and when I discovered it had 48mm rear threads, the urge to put on a Baader U was overwhelming. Even with the Baader in place, infinity focus is easily achieved on my Z cameras. Will do a few field tests in the upcoming days.

 

The last flower in your initial sequence does look as another A. blanda.

[StephanN]

I was tempted to have a look at my various Rodenstocks of 100mm focal length. The f/1.5 needs some arrangement to make it mountable, however the f/1.6 already was already adapted to a focusing helicoid, and when I discovered it had 48mm rear threads, the urge to put on a Baader U was overwhelming. Even with the Baader in place, infinity focus is easily achieved on my Z cameras. Will do a few field tests in the upcoming days.

 

Looking forward to the results

[nfoto]

The Rodenstock 100mm f/1.6 does work - sort of - for UV scenery. A quick and dirty hand-held test with my PrimaLuce Z5, BaaderU, and strong wind.

 

 

The familiar UV signature of Tussilago farfara is present. QED.

[Stefano]

That's quite nice. The image is not very sharp because of chromatic aberration and other aberrations, but it came out nice. If you didn't push the colors it should reach down some in UV, maybe 350 nm or so.

[StephanN]

The familiar UV signature of Tussilago farfara is present. QED.

 

Very nice (and you've possibly just identified another one of my odd ones, the one after galanthus nivalis)

[nfoto]

Stefano, shooting a 100mm lens for close-up with a hand-held camera under windy conditions and shutter speeds around 1/20 sec will never make really sharp images ....

 

StephanN: yes, your flower is unmistakenly Tussilago farfara. The genus is monospecific if memory serves (after botanists subsequent to Linnaeus removed allied species to other genera).

[nfoto]

By the way, the 100mm f/1.6 Rodenstock XR-Heligon must be the easiest ever lens to modify for UV use. The lens already has 48mm threads on the rear lens shell, which is what a Baader U requires. Or any other 48mm filter size. There is plenty of back focal distance as well so at least on a mirrorless camera, it can focus to infinity if one so desires.

 

 

A Cokin ring provides 52mm male threads on the main lens barrel. The Z focusing helicoid is made from a 65-65mm short helicoid (17-31mm type) terminated on the rear by a stock Nikon Z bayonet, on the front with a step-ring to give 52mm female thread. That's all there is -- just a few minutes job with epoxy glue.

[Stefano]

Stefano, shooting a 100mm lens for close-up with a hand-held camera under windy conditions and shutter speeds around 1/20 sec will never make really sharp images ....

Your image is still quite sharp, the softness is caused probably by aberrations caused by the wide aperture.

[nfoto]

The obvious optical "errors" which endeared many to use the Rodenstock up close due to its soft, almost painterly rendition, in fact mask the underlying quality of this lens. It is a design made for a specific purpose and if one attempts to mimic these conditions, much better image quality results. Set to infinity focus the 100 XR Heligon becomes flat-field and delivers sharp images. Contrast can be on the lower side as the lens never was intended for broad-band "white" daylight, though, but this can be corrected during the post procressing. Almost gone are the spherical and chromatic aberrations as well. The image circle does extend to cover the FX 'full' frame, but there is some quality fall-off towards the corners thus a DX 'half frame' camera would see virtually none of that quality deterioration. I decided to use it on my FX cameras just to learn how much of the covered image can be used later. Which will, of course, depend on the motif, and the intent of the photograph.

 

For UV the 100 Heligon offers a welcome alternative to the super-sharp UV-Nikkors and similar designs. Although UV response isn't great and spectral response likely drops off rapidly into the UV-A, what is recorded can yield interesting images.

 

 

Using a hand-held camera allows action to be more easily captured. Here an immigrant family enjoying a playful session with five-aside football ('soccer'). ISO 640, 1/30 sec with the 100 XR Heligon f/1.6 and Baader U on my PrimaLuce Z5. The entire FX frame is shown. Focused distance is around 100m so way off infinity.

[Andy Perrin]

Norway seems to be defrosting. Some nice color in there, even if they are technically aberrations.

[Stefano]

The image is clearly sharper at ~infinity.

[nfoto]

Putting the lens on a tripod will also help improve the overall sharpness.... Which is what I did with the comparison to the UV-Nikkor 105 shown below.

 

 

UV-Nikkor to the left, 100mm f/1.6 Rodenstock to the right. Both with Baader U and the PrimaLuce Z5, ISO 400 under overcast skies. The Rodenstock needed approx. 3EV more exposure than the UV-Nikkor.

 

The UV signature of the endearing little Tussilago farfara is strongly presented by both lenses, which is not very surprising. The UV-Nikkor was stopped down to f/11 to give sharpness all over the flower heads and the background, an option not available to the Rodenstock as it is a fixed-aperture lens. In fact, even with the flower heads almost in the same plane, it was impossible to keep all of them in the sharpness zone.

[Andy Perrin]

Was this made with the Z6? I see some horizontal line artifacts in the background.

[nfoto]

Both Z5. I might not have used Silkypix as I juggled several programs at the time.