Tandemfahren
Hello everyone,
Does anyone know where I can find a filter chart like that? – Specifically, I’m looking for one for a Jobo/LPL C7700MX, which has a yellow scale up to 200 and a magenta scale up to 170.
So the Durst chart won’t work.
I used to have one, but I can’t find it anymore, and I can’t find anything online either, not even on the Ilford or Jobo websites.
Many thanks
Frank
Wolfgg
Hi Frank,
And what do you mean by ‘filter table’? The mapping of filter values and gradient for variable contrast paper?
Addendum:
Oh, I’ve just spotted the subtitle: ‘B&W with colour head’. Here’s the information leaflet from a multigrade pack:
Jobo uses Kodak filter values; the mapping of gradient and filter is as follows:
00 199Y
0 90Y
0.5 70Y
1 50Y
1.5 30Y
2 0Y
2.5 5M
3 25M
3.5 50M
4 80M
4.5 140M
5 199M
Regards, Wolfgang
EJG
Hello Frank
Here is the table for the Jobo C6600 6x6 version. However, the colour head should be identical to the 6x7 version.
Jobo C 6600 Multigrade Filter Values
Gradient C M Y Factor
0 0 34 78 1
0.5 0 45 70 1
1 0 45 55 1
1.5 0 47 45 1
2 0 52 31 1
2.5 0 63 20 1
3 0 70 10 1
3.5 0 85 5 1
4 0 110 30 2
4.5 0 160 25 2
5 Not available
Extension factors
Filter
value Y M C
10 1.09 1.17 1.15
20 1.15 1.34 1.26
30 1.22 1.58 1.41
40 1.29 1.86 1.57
50 1.35 2.13 1.72
60 1.40 2.43 1.87
70 1.45 2.70 2.00
80 1.49 3.05 2.11
90 1.52 3.39 2.22
100 1.56 3.71 2.34
110 1.60 4.08 2.43
120 1.63 4.41 2.51
130 1.66 4.72 2.58
140 1.68 5.09 2.63
150 1.71 5.44 2.68
160 1.73 5.79 2.72
170 1.75 6.13 2.76
180 1.76 -- 2.78
190 1.77 -- 2.80
200 1.79 -- 2.81
Best regards
Tandemfahren
Hello ejg, hello Wolfgang,
That’s exactly what I was looking for! Many thanks for that. Where did you find it?
- It’s also interesting that values even softer than 0 can apparently be achieved if the magenta filter is turned all the way out. You’d just need to experiment to find the corresponding yellow value by taking a test exposure at Zone VII.
Actually, in my opinion, a hand-calculated table based on a target density for Zone VIII would be more effective, but it seems that doesn’t exist.
In my tests (for MGIV), Zone VII was always constant.
Happy printing everyone, and thanks again to all
Frank
peterkrumm
Hello everyone,
Does anyone know where I can find a filter chart like this? – Specifically, I’m looking for one for a Jobo/LPL C7700MX, which has a yellow scale up to 200 and a magenta scale up to 170.
So the Durst chart won’t work.
I used to have one, but I can’t find it anymore, and I can’t find anything online either, not even on the Ilford or Jobo websites.
Many thanks
Frank
Have a look here:
http://sw-magazin.de/swmag_erste_schr_02_4.htm
or here as a PDF:
http://www.ilfordphoto.com/aboutus/page.asp?n=116
Peter
Wolkenkratzer
Hello,
You can actually bin these tables, because how your enlarger affects your paper depends on various factors.
At first, it was a bit of a trial and error process for me; I stuck to these tables, but somehow it just didn’t work.
Until a very experienced photographer gave me a helping hand.
I have a Kaiser VCP 6000 enlarger and an L1000-cls450.
The Kaiser has the following values as a reference for ADOX Agfa Classic 310 paper, and these differ significantly from the table.
Grade 0 = y35; i = 4.44
Grade 1 = m10; i = 2.54
Grade 2 = m30; i = 2.95
Grade 2.5 = m80; i = 3.810
Grade 3.0 = m130; i = 3.808
i = relative paper sensitivity in lxs, measured at f/8 at 10x enlargement using a Schneider 2.8/50mm lens.
The filter values for my Kaiser paper correspond to within +/- 10% of my densitometer readings.
The paper was calibrated using a grey scale, which corresponds roughly to the ideal characteristic curve.
This makes it relatively easy to determine the paper’s full copying range. It took me about half a rainy Sunday to do this.
You have to work out the speed, correction factors and gradient for yourself; that’s what I was told some time ago.
Regards, Thomas
Tandemfahren
Hello Thomas, hello everyone,
You’re certainly right, strictly speaking. If you really take it to the letter, even the numerical values for the gradients make no sense at all. After all, there’s an Agfa series, one from Ilford, one from Kodak and, last but not least, an ISO standard. Take your pick.
Years ago, I shot the Kaiser-Durst table (the one for equal exposure times, with two filters) using a grey scale wedge with my VCP7002 on MGIV streaks; lo and behold, Zone VII was wonderfully consistent!
So you can work with it, and that’s not bad at all, even if it isn’t the be-all and end-all.
Basically, my only concern was that Tim "Tmoog" could get started in Japan with my old LPL unit without tearing his hair out. He can manage that now.
So many thanks for all the useful contributions
Frank
TiMo
Basically, my only concern was that Tim "Tmoog" could get started with my old LPL device in Japan without tearing his hair out. He’s sorted that out now.
Many thanks for the info. The first attempts have been more or less successful. Thanks to Frank, I can now have a go at making prints myself.
For the sake of completeness, I’d like to add the settings specified in the ADOX Easy Print instruction leaflet:
For Kodak (= Beseler, De Vere, Chromega, Fujimoto, IFF, Jobo, LPL, Omege, Paterson, Vivitar, Simmard)
Level 0 0M 80Y
Level 1 15M 60Y
Level 2 50M 35Y
Level 3 70M 15Y
Level 4 85M 5Y
Tandemfahren
Hi Tim,
Sorry, your name is TiMo, of course, not Tmoog...
This table doesn’t apply to your LPL. Your scale goes up to 170 and 200. These scales are purely down to the manufacturer’s discretion.
Have a good time
Frank
Wolfgg
If you work with different types of paper or from different manufacturers, this chaos of gradient can be quite a nuisance. But: things weren’t any better 50 years ago! Back then, the confusion over gradient was simply built into the fixed-gradation papers; variable contrast paper didn’t exist yet. For every manufacturer (Agfa, Argenta, Tura, Mimosa...), ‘hard’ meant something different. But with variable contrast papers, you can largely resolve this problem using split filtering: two exposures for each enlargement: first one with a little yellow added, tuned to the highlights (leaves the shadows too flat), and then a second, hard exposure tuned to the shadows, which pulls the shadows down completely and ensures that the areas intended to show full black automatically achieve the maximum paper black. The effective paper gradient is thus adapted with astonishing precision to the negative, without the need to set a specific gradient on the mixing head. I recommend that anyone unfamiliar with this process give it a try.
Regards, Wolfgang
TiMo
Hi Wolfgang, that sounds very interesting. Once I’ve gained a bit more experience and got the hang of it, I’ll give it a go.
Am I right in thinking that – if I don’t have a device to measure the actual contrast on the paper – I’m best off simply using a table as a rule of thumb? Regardless of the paper used. That might then be grade 2 according to my settings, but in reality grade 2.5. But who cares, if it looks good?!
Wolfgg
The actual contrast settings used for the two exposures (i.e. the filter values set) do not need to be particularly precise; the first (soft) exposure can be set to level 1.5, 2 or 3. The only important thing is that this first exposure does not yet cause any washed-out shadows. Or to put it another way: on the test strip for the first exposure, the shadows must still be grey. The second exposure, which then completes the shadows, can also be grade 4 or 5; it is purely a matter of taste (you need to experiment a little and compare). The only important factor is the exposure time for both exposures. For the first exposure (the soft one), the highlights must not become too grey; for the second (the hard one), the areas of full black must be exposed to just the point of full black – this can be done very quickly and accurately even with a simple darkroom exposure meter. Contrast measurement is not required.
The filter tables given in the posts are of two types: some use only one filter (Y or M) at a time, like the one I’ve specified; others use two filters simultaneously to achieve as consistent an exposure time as possible across all grades. The second approach is of little use for split filtering, as it’s rather a nuisance having to fiddle with the edges of two filters all the time. Therefore: for the first exposure, simply turn in the yellow filter to approx. 2 degrees; for the second, turn in only the magenta filter to approx. 4 or 5 degrees. Precise adjustment can only be determined from the test image; for example, if the highlights are too flat and the shadows still very bright, make the first exposure slightly harder, i.e. use less yellow or no filter at all. If you need to turn in magenta for the first exposure, the negatives are too flat.
Regards, Wolfgang
piu58
I recommend that anyone who isn’t yet familiar with this method gives it a go.
Regards, Wolfgang
I, on the other hand, recommend something else. In my opinion, it is completely irrelevant which gradient is where on the filter chart. What interests us are
changes
in contrast. If the print is too soft, then you need to add ‘more hats’. I always work on the basis of 15% = 1/2 stop. Whether that’s exactly right doesn’t really matter: if it’s still too soft, just add more filters.
After a few evenings, you’ll know which filter settings to start with – ideally starting from the softer side – and which stops make sense.
Wolfgg
Hi Uwe,
But you really should have a rough idea of which positive grade to use. Otherwise, you might not realise for years that there’s a problem with your negative processing, and that the film is being developed far too hard or too soft, resulting in a loss of quality.
Best regards, Wolfgang
piu58
Hi Uwe,
But you really should have a rough idea of which positive grade you’re using. Otherwise, you might not realise for years that there’s a problem with your negative processing, and that the film is being developed far too hard or too soft, resulting in a loss of quality.
Regards, Wolfgang
Actually, not even that. The starting point is always using the film without any filter at all – which is simply a gradient of 2 for this paper. There are clear differences; for example, warm-tone papers are harder.
TiMo
The topic that never leaves my mind.
I finally want to try out my Fujimoto enlarger. The colour filter scales go up to 150.
To get some starting values for the gradient, I simply took the values for ‘Durst max 130’ and ‘Durst max 170’ that Ilford specifies in
this document (PDF, page 3, top right-hand column) and averaged them.
Does that make sense, or am I just wasting paper?
If anyone has a table for the Fujimoto, I’d be delighted, of course.
I can’t create one myself because I don’t have any measuring equipment.
Thanks and best regards,
Tim
piu58
Absolute values are irrelevant. What matters are the relative changes in the filter settings. If the image is too soft, you need to add more magenta. The exact amount required for each step may vary slightly from one device to another.
Trying to replicate the fixed paper gradations is the wrong approach. Filtering offers more possibilities and a different way of thinking.
TiMo
Hi Uwe,
I wouldn’t have been surprised if you hadn’t been the first to reply ;)
My understanding is that the advantage of mixing heads in black and white is that you can adjust the contrast without having to change the exposure time you’ve already set. In other words, I get nice highlights at 25 seconds, but I want slightly deeper shadows, so I can simply set a different filter mix without having to change the time. That worked well with my other enlarger.
I see the advantage in having a table to start with, which you can then refine as needed.
As I can’t measure anything, I can’t work out how much magenta in and yellow out makes a difference of one stop,
Thanks and best regards
Tim
piu58
> without having to change the exposure time already set
The question is: which exposure time? The one for the highlights? Or the one for the mid-tones? It never works.
If you apply a non-compensating filter – in other words, simply adding more magenta to make the image a hardener – then the exposure time for the shadows remains the same. For this reason, for the initial steps I base my approach on the minimum time for maximum black, which I believe is a very important concept. In the final steps, i.e. the fine-tuning, the highlights are more important.
Incidentally, one step of adjustment is roughly 30–40% magenta or yellow (with Durst, up to 130%).
TiMo
Hi Uwe,
Thanks for your reply.
I’ve always taken a very traditional approach to this: adjusting the highlights via exposure time and the shadows via contrast.
I use a test strip to determine an exposure time that still gives me suitable highlights. Depending on the paper and negative, this is usually around f/2 or f/2.5.
I look at the test strip and if the darkest areas are still too grey, I increase the contrast. Not just more magenta, but – according to a table – more magenta and less yellow.
That’s always worked quite well so far.
Best regards, Tim
