Ulf-Benno
Dear photography enthusiasts,
At Klaus Wehner’s suggestion, I tested the black-and-white reversal kit he developed, and I’m really impressed. The chemicals (liquid concentrates) are easy to use and the results are truly impressive.
So far, I have developed two rolls of ADOX CHS 100 II film simultaneously using the rotary development method. For this film type, a sensitivity of 24 DIN/200 ISO is specified at 22°C and a development time of 10 minutes 30 seconds. An initial developer volume of 125 ml is recommended for each roll.
I accidentally developed for about 12:00 minutes, and some shots taken in low-contrast lighting have turned out just a tiny bit too bright. The shots were taken in good and poor light, overcast weather, sunshine and in snow. Of the 78 shots, none were botched and none were too dark. The potential contrast range was utilised very impressively. The slides exhibit a beautiful clarity and sharpness. The resolution is very high, comparable to earlier 15 DIN films.
Rotary development was unfamiliar to me; you have to roll the developing tank briskly back and forth on the table throughout the entire development time. To do this, the tank must of course be airtight (use fitting grease for the rubber seal). Not every type of can is suitable for this purpose due to its design. I fitted my Czech Plastimat can with a hollow cylinder and a funnel insert made of fine cement mortar (with acrylic varnish) to reduce the internal volume. To be able to roll the can, I wrapped it in a long strip of cardboard and glued it in place. Modern cans are presumably designed for this.
This rotary development process is a bit laborious at first, but it guarantees consistent results, as the initial developer is only used once as such.
The Bleach bath consists of two pre-dissolved components and has a shelf life of at least a few weeks. As a precaution, however, you should always test the older Bleach bath first with a black film or black photographic paper.
The clarifying bath is sensitive to oxygen and must not be left open.
Secondary exposure is straightforward; I always use fluorescent light.
The used primary developer can simply be used as the secondary developer, or any other developer that has been used to a greater or lesser extent. Fixing is not strictly necessary, though it may be required for films with residual dye.
So I can highly recommend this developer set and hope that it becomes the global standard.
Many thanks to Klaus Wehner and the ADOX film producers!
Ulf-Benno
KlausWehner
Thank you, Ulf-Benno, for this detailed report.
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I’m delighted that even the first development has produced such good results.
That was the idea behind my chemistry kit: anyone who follows the instructions will achieve good results very quickly (which are significantly better than those obtained using the standard process).
All the feedback I have received so far regarding my chemicals confirms that good results were possible practically straight away.
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The quality of the slides comes across to the viewer just as Ulf-Benno described: sharp, brilliant and rich in tonal range.
In addition, a high speed can be achieved: ISO 200/24 and even ISO 400/27 (with the Adox CHS 100 II).
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It is obvious that my chemicals have a more complex composition.
It is not easy to dissolve all the ingredients in a concentrate and keep them stable.
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Of course, Ulf-Benno is right to point out the risk of oxidation in this context.
It would help to decant the concentrates into smaller portions (into smaller, tightly sealed bottles).
I have also thought about putting together kits that are just enough for two films.
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If anyone has any further questions, please feel free to contact me: klaus.wehner@web.de
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Thanks, Ulf-Benno!
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Best regards,
Klaus
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Ulf-Benno
Another update on the bleach bath.
Although there have been successful tests showing it lasts for over a year, my bleach bath had gone off after 3 weeks and 3 rolls of film. Testing with a black piece of photographic paper is not sufficient. Photographic paper requires much shorter bleaching times. For film, these can sometimes be five times longer. If the Bleach bath is very heavily used, the bleaching process may not even be completed.
The only reliable test, which is essential for used Bleach baths, is to carefully examine the film immediately after bleaching.
The film must no longer be black. The positive must already be visible. The film must be whitish, or yellowish or violet in colour, throughout. This is easily visible even in subdued light. If black silver is still visible, processing must continue immediately using fresh or regenerated Bleach bath.
Good luck!
Ulf-Benno
KlausWehner
Thanks, Ulf-Benno!
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That’s important information for me.
However, it’s difficult to make a remote diagnosis at this stage.
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The test was designed to identify problems like this.
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I can confirm that the control sample is still working perfectly in my lab.
Other testers have consistently produced good results.
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I have circulated minor variations in the Bleach bath.
Once all the responses have been evaluated, this may provide some indication.
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I am currently considering two potential causes:
1. Packaging and transport. (My reference sample is stored in a high-quality laboratory glass bottle with oxidation protection).
2. Cleanliness during preparation (even the slightest contaminant from traces of other chemicals can significantly reduce shelf life. I have already explicitly pointed this out in my instructions for use).
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The fact that everything works without a hitch in my laboratory is only half the battle.
Now it is a matter of finding out what can happen outside my sphere of control.
I am grateful for any suggestions.
I am confident that I will also find solutions to any problems that may arise.
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Perhaps smaller-scale preparations are also a viable option?
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Ultimately, the aim is to establish a completely new chemistry.
It’s actually quite understandable that this isn’t exactly straightforward.
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My heartfelt thanks to all the testers who are helping me with their feedback!
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Warm regards
Klaus
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KlausWehner
After a brief discussion with Ulf-Benno, I was able to explain the seemingly puzzling behaviour of the chemical reaction.
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The cause was a significant deviation from the operating instructions.
The tolerances for the reaction time, concentration and duration were greatly exceeded.
The deviations were in the order of approximately 200% to 1000%.
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With such serious deviations, however, normal results can no longer be expected.
But I see this as a learning experience too.
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Once the processing instructions are followed again, good results can be expected once more.
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Nevertheless, this has given me cause to reflect on the Bleach bath.
There is room for improvement in the areas of packaging, transport and (suboptimal) storage at the user’s premises.
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Ulf-Benno, I am grateful for your many valuable tips!
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Warm regards
Klaus
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HGR
Hello,
I’ve now used up my second set of Klaus Wehner’s chemicals and have developed the remaining stocks of Agfa Scala, Adox Silvermax, Adox CHS 100 II and
Foma R 100 as roll film and 35mm films. There was only a problem during the second development process: streaks in the bright areas of the slides.
I suspected the cause was that I had skipped the pre-rinse this time and/or used a quantity of chemicals that, whilst in line with Klaus’s instructions, only filled about a third of the rotating tank. For the subsequent developments, I pre-rinsed again and used a quantity
of chemicals that filled the tank halfway. With the Jobo 2500, which has two roll film inserts and one 35mm insert, that meant just
5 films per litre, so the entire batch was used up. But the result: no streaks!
As a thrifty chap, I’ll now have to experiment again with smaller tanks and film spirals!
Overall, I find my slides beautifully brilliant and luminous, even when projected in 6x7 and 35mm panorama formats.
Many thanks to Klaus for this actually relatively easy-to-use set of chemicals for black and white slide development, which has led to a
renaissance of good old-fashioned slide production for me, including in colour.
Warm regards
Hans-Gerd
KlausWehner
Unfortunately, I can only give a brief reply today:
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1. Pre-rinse: this is not part of my process and is not necessary.
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2. Chemical volume: 125 ml of working solution is sufficient for the optimal development of a film.
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3. Cost-effectiveness: even if you were to use significantly more chemicals per film, processing it yourself is still considerably cheaper.
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Even though the test phase is over, the chemical kit is still available from me.
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Once again, my special thanks to Hans-Gerd!
The slides are excellent!
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Warm regards
Klaus
