andreasdegner
Hello,
I’ve taken the trouble to start calibrating my photographic papers using a grey scale, so I can approach printing in a slightly more systematic way. I started with the ADOX MCC. The following equipment was used: a Meopta Opemus 6 enlarger (condenser) with a 150W opal lamp (the one from FOTOIMPEX), filter set 0-5 (also the inexpensive ones from Impex), dark red Duka light (the red bulbs; I had previously carried out a veil test with pre-exposed material), Adotol developer (constant), which isn’t too old yet.
Procedure: Place the grey scale in the negative stage, insert the appropriate filter, and determine the exposure time so that both white and black appear on the streak. I carried out the evaluation with the dried paper as follows: Find the x/y field that can just about be distinguished from black and white. The corresponding density difference y-x of the grey scale, multiplied by 100, should then give the ISO-R value for this gradient.
Results: With filter 2, I got an ISO-R of 150. According to the datasheet, gradient 2 should have a value of 100. The difference is quite striking, almost 2 stops. With filter 5, I get ISO-R=80, which is still too soft (the datasheet says 55).
Is this normal? My filters haven’t faded and I’ve always handled them with care. Could it be that the opal bulb isn’t emitting enough blue light? I definitely want to be able to use the MCC’s hard gradients as well; unfortunately, with my current settings, I can’t.
Oh, and I can rule out gradient diffraction caused by stray light from the enlarger, as the area around it is covered with black fabric.
Can anyone help me?
Best regards
Andreas
Tandemfahren
Hi Andi,
You’ve used the wrong endpoints for the paper’s density scale. The correct range, in line with the standard, is between 0.09 and 1.89 logD (using a Stouffer grey scale in thirds, you can clearly identify 0.1 and 1.9 logD as the endpoints; precise measurement is only possible with a densitometer).
You should be able to get closer to that, although the contrast actually achieved in real life probably doesn’t quite match the standard.
But it’s great that you’re making the effort – a real thirst for knowledge :-) Well done
Frank
andreasdegner
Hi Frank,
I suspected as much – that it was more of a ‘standardisation issue’, as I don’t have an unusual processing chain. Since the MCC is supposed to achieve a DMax of 2.3 (though I don’t know if it does in my case, as I don’t have a reflectance densitometer), I’ve probably set the black end of the scale one stop (or 0.3 density units) too low. If you took that into account, my values might be more or less correct.
Could it still be the case that you can get even harder gradients out of the paper with different filters or light sources?
Best regards
Andreas
Tandemfahren
Hi Andi,
2.3 is probably a bit optimistic; I don’t have a proper densitometer either, but anyway: the problem with determining the gradation is always that the variation curve is quite flat at both ends, which is why it makes sense to agree on two endpoints where there is still a reasonable amount of slope (and therefore detail). For anything beyond that, you can’t really make out anything properly in the image anyway.
More hoods with different light sources or filters? In principle, there are of course differences; for example, it’s always said that condenser lighting is better than diffuser lighting, but I don’t know if that applies in your specific case.
The type of paper, age, storage conditions and, of course, development also affect the contrast (Dokumol!).
Ultimately, though, none of this is rocket science; you never really need a true grade 5 or even higher (manual split-grade would be a possible exception).
If you really do run into trouble, you can always ‘tinker’ with the negative (for non-Bavarians: ‘manipulate’), e.g. with a strong selenium toner or, quite drastically, with an indirect sulphur toner.
Hope that’s helped
Frank
andreasdegner
Hello Frank (and everyone else on the forum),
Density figures aside – I’ve done another comparison with the Fomabrom variant 111. To achieve the same image impression from a negative, I need filter sheet 2 with the Fomabrom, but with the MCC I need no. 4! That’s quite a striking difference, which confirms my impression when calibrating. The negative actually has normal contrast. With the Foma, I have much greater leeway in the hard gradients with my equipment than with the MCC. Either the MCC doesn’t work well with the filter sheets from FOTOIMPEX (these are the ones priced at €13.09 for the 9 x 9 size from the current catalogue), or I’ve ended up with a dodgy batch of paper. The paper should actually be quite fresh. It was delivered about two months ago, and I’ve stored it in a cool, dark place.
In case the host is reading this, I’ll give the emulsion number: 0110 0220-1-2D 08-11.
I hope the problem sorts itself out.
PS: When lith printing this batch of MCC, I noticed some marbling in the highlights (see my litho thread from a few weeks ago). Perhaps there’s a connection there...
Best regards
Andreas
andreasdegner
Hello,
I’d like to ask the group again: doesn’t any of the MCC printers have the problem I mentioned above with the contrast filters? I’d be really keen to know whether I’m doing something wrong or if it’s down to the material. With my settings, I can only get a maximum of grade 3 from the paper. The datasheet isn’t very helpful either. It doesn’t mention the exact film filters, referring instead to ‘standard commercial filter sets’. Or are there no differences? I had a quick Google and read that Agfa also offered filter sets where Grade 5 had a stronger magenta...
Best regards
Andreas
PS: Mirko, if you’re reading this, I’d appreciate a comment. I’ve already written to Impex about my problem via the contact form, but I haven’t received a reply yet.
MirkoBoeddecker
Hello Andreas,
No, apart from you, nobody else seems to be having this problem in this form; at least, I’m not aware of any other cases, otherwise we would have withdrawn the material.
You’ve had problems with our material in other threads as well.
Perhaps you’re still making certain mistakes when experimenting. There are plenty of things you can get wrong in the darkroom. How much experience do you have? Do you really feel confident enough to assess contrast visually?
I took the trouble yesterday to perform exposure on a few sheets from the affected batch, using filters 3 and 5 from our set respectively.
There were clear differences in the hardness. I then cross-tested with Magenta 100 on our Durst head and could hardly see any difference to filter 5, at least in the dripping-wet prints. I’ll take another look at it today.
A cross-check with Vario Classic showed that our MCC turned out slightly harder than Vario Classic. I haven’t opened any more Foma paper. I hope you understand.
However, our inexpensive Vario filters are not subject to any reference calibration either. They are a stopgap solution for those who do not have access to a colour head. That doesn’t mean they don’t work, but a colour head naturally works more accurately. If only because dichroic, vapour-deposited filters do not fade.
For proper calibration tests, I would therefore always use a colour head.
For years, the photographic industry has been using DURST heads for calibration. We have the calibrated Agfa devices from quality control here.
We use these to test our materials.
As for your troubleshooting, now that it’s winter, I would first check whether you have strictly adhered to the developer temperature and time. In my view, a gradation test at 18 degrees or without a stopwatch would certainly be doomed to failure, as deviations in development time (particularly if it is too short) have a significant impact.
I always start fresh and run a water bath into my tank.
Best regards,
Mirko
KlausWehner
Hello everyone,
I’m absolutely delighted that there are still people out there who take photography seriously and engage so deeply with the subject!
Many years ago, I had the same idea: to calibrate my photographic paper (Agfa MCP) so that I could work reliably using the zone system (with a Durst Fabmischkopf).
I was also keen to determine the exact extension factors caused by the colour filters, as well as to obtain precise data on split exposure (adding exposures with different gradients).
I really did try to work with precision! But it didn’t work with the desired accuracy.
At the base and shoulder of the curve, the gradation curve is naturally so flat that an exact determination of Zone 0 and Zone X is simply subject to too great a margin of error. After just a short time, the developer changes and produces significantly different results. Streak effects (in the lens), fluctuations in lighting brightness, black shield effects...
For weeks and months, I did nothing but test prints – but ultimately failed to achieve my goal. The values I found were often not sufficiently reproducible in practice.
Nevertheless, it was by no means a waste of time! I learnt a great deal. Today, I believe that manufacturer specifications such as the R-value are merely a rough guide. Many figures and curves suggest a precision and certainty that exists only on paper. The multitude of tolerances makes it almost impossible to verify such specifications.
I have learnt that photography is not about numbers and data. It is about artistic expression – and that cannot be achieved with tables of figures and a calculator.
I have learnt that one must free oneself from the recommendations of manufacturers and experts. My film developments, for example, now have a significantly higher contrast index than is generally recommended (0.8...0.9). All my course participants (and I myself, too) achieve good results this way (on MCP paper with a gradient of 2...3).
I have learnt that photography is not merely about reproduction. Your own path is the right one. You find it by having a goal in mind. Only when you know where you want to go will you find the way. (Dead ends and wrong turns included).
Every good print is unique. And that’s a good thing.
Your own experiments and tests are extremely helpful for this, probably indispensable. But they aren’t everything. You won’t be able to recognise the essentials through them.
Warm regards from Paderborn
Klaus
piu58
I really did my best to work with precision!
But it didn’t work with the level of accuracy I was hoping for.
I’ve found a very pragmatic approach when working with a mixing head. I set the standard exposure time for the paper, i.e. the time required to achieve a deep black. If you expose for significantly less than this time, you won’t get any black in the image.
This standard exposure time hardly changes when you add or remove filters,
+30% under 1/6 stop. So I stick to this time and adjust the highlights using contrast. For Durst skids: 15% more magenta = 1/2 maximum level. It doesn’t matter exactly where I’m at right now; adjustments are made anyway. Image too soft: more magenta. Image too hard: less magenta. That’s it. I don’t like adding yellow, because the shadows suffer as a result. It’s also rare that I have films developed so hard.
andreasdegner
Mirko,
First of all, thanks for doing the counter-test. I’d also prefer a colour head for my Opemus, and I’m on the lookout for one. I’m well aware of the problem of filters fading. When I started enlarging in my shared flat five years ago, I wondered why I couldn’t get gradients 4 and 5 right. Later, I realised that the filters in question had completely faded (Ilford filter set from eBay). That taught me a lesson, and I bought a new set of filters. However, the fact that the filter industry is so unstandardised does bother me; but for lack of alternatives (no colour head), I can currently only use VC paper. And that’s why I wanted to introduce some systematic approach through my test.
Now, I don’t have a reflectance densitometer for evaluation. I’m also aware that a lot may depend on the developer/paper combination (can Adotol consistently, aka N113, produce good blacks from the MCC?). However, I monitored the development time (2 mins, which should be enough for MCC, shouldn’t it?) using a timer, and the temperature remained constant at around 18°C throughout the session.
What I can comment on, however, is the direct comparison between two papers under otherwise identical conditions. That is exactly what I did with my test print, which revealed significant differences between Fomabrom variant and MCC: same negative, Fomabrom variant vs. MCC. With the former, grade 2; with the latter, grade 4 for the same impression of contrast (the developer used was freshly mixed Neutol WA 1+7). Grey scale test or not, the fact is that, based on this test, I simply have less headroom with the MCC compared to Fomabrom. That’s why I also thought that the hard gradient on Foma kicks in with less magenta than on the MCC... and then I can no longer work properly with the MCC on problematic negatives (with my current gradation control).
Mirko, what light source did you use for your test with the films? And which developer? Even if the filter films are uncalibrated, it’s still very unlikely that it’s down to the different batches we both have, isn’t it?
Best regards
Andreas
KlausWehner
Dear Uwe,
I saw for myself in Paderborn just how quickly and reliably you achieve good results.
I’m currently working with the same method – though in a way that’s almost the reverse of your approach.
I’m using a slight yellow filter (10–40 yellow). The advantage is that yellow filters have significantly lower extension factors than magenta.
I base the exposure (standard printing time) on the highlights. I control the blacks via the gradient.
There are good reasons for every step – but I don’t want to go into detail.
Everyone follows their own path. That’s exactly how it should be!
In medicine, they say: whoever heals is right.
Here, one could say that whoever achieves good results is right.
Greetings to Leipzig!
Klaus
michael-kielgmxnet
... I realise, too, that a lot can depend on the developer/paper combination (can Adotol consistently produce a good black from MCC, aka N113?). However, I monitored the development time (2 minutes – that should be enough for MCC, shouldn’t it?) using a timer, and the temperature remained constant at around 18°C throughout the session...
Hi Andi,
at 18°C, 2 minutes may be too short depending on the type of paper, especially with baryta paper. Depending on how much silver the emulsion contains, it may still be active even after more than 3 minutes. So first try extending the time or perhaps keeping the developer slightly warmer. Over-developing is practically impossible with photographic paper, unless you leave the print in the developer for half an hour.
It seems to me you’re using two different paper developers (Neutol WA and N113)? I’d stick with N113 for now; it performs much more consistently than Neutol, and the difference in image tone is negligible anyway, as neither is a warm-tone paper.
Edit:
N113 (aka Adotol Konstant) is a really good all-round developer. It should definitely allow for good maximum black levels, regardless of the paper used. The only one I find even better (though only by a hair’s breadth) is Moersch’s SE6, though that does produce a distinctly cool image tone.
Tandemfahren
Hi Andi,
I’ve been following this and have been thinking about it. It might be worth doing a detailed veiling test with your papers. I suspect your lamp filters are the issue.
What sort of light are you using?
The fact that you get much harder results with Fomabrom suggests that the filter film isn’t the cause.
And you’re getting marbling in the highlights; that sounds like fogging.
Hi Uwe, that’s an interesting technique you’re using there. When you first mentioned it (without explanation), I thought, ‘He’s got a screw loose, that madcap...’ but then again, the proof is in the pudding. Brilliant!
Regards,
Frank
andreasdegner
Frank,
I use the dark red bare Duka bulbs. They give off a very dim light, and even with them, the ADOX Fineprint Vario Classic is free from fogging up to 4 minutes (and that’s the paper most prone to fogging from Duka light). I’ve tested the two papers you mentioned separately anyway, so I can rule that out as a cause.
I only get the marbling when lith printing with the MCC; it never happens with conventional development.
It looks to me as though the MCC needs more magenta than I can produce with my filters. However, as I said, I don’t have a colour mixing head with which I could test this.
@Mirko: for me, grade 5 also turned out harder than grade 3 (with MCC) – but just not hard enough
Best regards
Andreas
TR
Hello everyone!
I, too, have been spending a lot of time over the last few weeks testing my positive film materials (Schwarzschild, Nachdunkeln, selenium toner, developer, etc.).
but not quite hard enough
Perhaps you simply need to conduct the negative development for longer in general, so that they achieve a certain level of contrast that suits your taste and can also be reproduced accurately with the MCC.
There was also talk here of ‘calibrated’ multi-contrast filters. Such filters don’t need to be calibrated, as you’re working with test strips anyway, or use the (same) filter for the final print as you did for the actual test strip. Unless, of course, you perform exposure or development of your negatives according to the zone system, in which case they always have identical contrast. But as a rule, you simply have to try out different filters until the result suits your taste.
Regarding Adotol W and N113: I tested them with Fomabrom Variant. The densities are the same (deep). The image tone is very slightly (but noticeably) warmer with Adotol (1+9), which is why I prefer it.
On development time: I get good results using Adams’ factor rule – the time for the first visible image traces x 6 = total development time.
Incidentally, I’ve noticed that a slight increase in contrast can also be achieved by agitating the developer more vigorously – just as in the negative process. Since then, I’ve also adopted a specific agitation rhythm in the positive process, which I naturally have to maintain when processing test strips as well.
Greetings to the other darkrooms,
Thomas
KlausWehner
Hello everyone,
A colleague here has recently compared Ilford and ADOX papers. The result was that the papers required significantly different filter settings to achieve the same positive contrast.
Several years ago, following the closure of a darkroom, I came into possession of some unknown contrast-reversing baryta paper (from Banse & Gromann).
The paper still worked perfectly (the whites were clear and free of haze, the blacks were deep, rich and of high density). However, I still couldn’t use it because the paper had such a flat gradient that I couldn’t achieve usable results even with my increased negative contrast. I don’t think that was (just) a superimposition effect. I think the paper simply had such a flat gradient.
My experience, therefore, is that papers can have vastly different contrasts.
My conclusion from this is that I have familiarised myself with one type of paper and tailored my entire processing workflow to it.
If you cannot achieve the right contrast with your ‘preferred paper’, then in the long run you should adjust the negative contrast.
I consider it likely that the aforementioned Fomabrom variant paper simply has a higher gradient than the MCP by nature. To my knowledge, there is no binding standard for paper gradients. Thus, every manufacturer probably has its own method of determining contrast.
It is important that the batches of a particular paper brand are consistent. I have long-term experience with Agfa MCP. Its quality has remained fairly consistent over many years. I hope for the same level of consistency from the ADOX MCP.
Incidentally, I also consider a development time of 2 minutes at 18°C to be far too short for MCP.
My times are 3 minutes at 20°C (at 18°C I would perhaps assume 4 minutes).
"Marbling" actually indicates (extreme) underdevelopment. Once papers are fully developed, such effects should not occur.
Best regards
Klaus
Tandemfahren
Hi Klaus,
It’s great to hear from you again!
Yes, there is an ISO standard for paper gradations. It’s just that nobody sticks to it.
Andi only gets his “marbling” when he uses lith printing. Even so, developing according to the factor rule should answer the question about development time. Two minutes really isn’t very long.
I find it hard to believe that Fomabrom is supposed to be that much harder on its own as a hardener.
All the best,
Frank
KlausWehner
Hi Frank,
Yes, I’ve been a bit out of the loop lately.
I’ve been really busy.
Unfortunately, I can’t say for sure whether Fomabrom is actually a significant hardener. I haven’t worked with the paper yet.
But I can well imagine that being the case.
I also occasionally see these ‘marbling’ effects in the negative – with extremely hard development (‘line development’) in conjunction with underdevelopment.
This is a sign of insufficient development. If a development delay isn’t enough, then a (slight) increase in the phenidone concentration helps. (This isn’t possible in the lith process, though. In this case, I might increase the total developer concentration – perhaps it’s also down to the temperature being too low).
A proper resolution of the original questions can probably only be achieved through your own experiments in the darkroom.
I’m afraid even Mirko is in over his depth here. This isn’t something that can be sorted out ‘on paper’. The devil is in the detail!
However, grappling with such problems in practice helps enormously in finding your own way. This accumulated experience is truly worth its weight in gold! (even if it is very tedious at first). It provides the necessary confidence to achieve good results with ease.
Warm regards
Klaus
KlausWehner
Addendum:
The matter just wouldn’t leave me alone.
I looked for my notes from back then.
I must preface this with a few words:
In 2004, I bought a new enlarger: a Binagon Color 4x5 inch.
Preliminary tests showed that the colour mixing head generated too low a yellow density, meaning I couldn’t achieve the very smooth gradients with the Agfa MCP.
I then modified the colour mixing head and fitted an additional dichroic yellow filter.
I used this modified colour mixing head to calibrate the MCP at the time (the developer was Agfa Neutol).
Among other things, I determined the R-value of the paper and the exposure time extension factor when changing the filter density (in 10-step increments from M 170 to Y 140).
With 000 filtration, I found an R-value of 1.47; with M 160, an R-value of 0.78; and with Y 140, an R-value of 2.04.
My aim was never simply to confirm figures that manufacturers had once published. On the contrary: I wanted to create my own standard using the resources available to me and tailored to my specific circumstances.
I had a long-term goal: for split exposures, I wanted to create a system that would make it possible to calculate the development of all densities in the image in advance when combining different exposures with different gradients on a single sheet of paper.
That should actually be possible – but it failed due to excessive tolerances and the complexity of the task.
Today I work exclusively with test strips.
Warm regards from Paderborn
Klaus
