DennisG
Hello again,
I’d like to have a bit of a play this evening with the “Rollei RBM3” multigrade emulsion and some Ilford MG paper.
I’d like to use my colour mixing head to control the contrast, but I can’t find any specifications for my enlarger on the Ilford website.
Question one
: I use a Krokus enlarger – is this comparable to one of the more common models? So that I could use these values?
Question two
: Finding the settings for Ilford papers was easy, but unfortunately I can’t find any information on the correct colour mixing ratios for contrast control with Rollei RBM3.
Can I apply the Ilford settings here exactly as they are?
Many thanks and have a lovely afternoon or evening, everyone.
MirkoBoeddecker
Don’t stick too rigidly to any filter tables. They’re all smoke and mirrors.
Yellow makes it softer, magenta makes it harder. This relativity is important. Make a print at around three (add a little magenta) and develop the image. Then have a look at it and decide whether you want to go harder or softer.
It’s almost completely useless to know whether you’re at 3.25 on some fictitious scale. You always work relative to the last test print.
The only thing this table helps with is seeing how many filter values roughly equate to one gradation. But you can also quickly estimate this by interpolation. Tip: normally, it doesn’t get any harder at around 75–80% of the available magenta values (provided the filters haven’t faded). Divide the range below that by three and that gives you roughly one gradation.
?
Krokus did not have colour mixing heads. Your device probably has a different head fitted (Meopta).
?
Liquid photoemulsion is only controllable to a limited extent, and the gradation depends on the application and the substrate. Any kind of table would be useless here. Just go by feel. It’s right when it looks good to you!
Unfortunately, testing with industrially coated paper and transferring the results to self-coated objects won’t work, as your coating result will be light years away from the standardised paper.
Therefore, always coat test objects as well and proceed as described above.
?
Good luck!
TR
Hello, Krokus did indeed have a colour mixing head in its range:
€
But as Mirko has already pointed out: the settings must be adjusted by eye, as every negative has a different inherent contrast, depending on the lighting conditions and development time (for B&W). As a guide, I have noted down the approximate gradation values for each magenta setting on my Krokus. But this is really only for a rough guide.
DennisG
Hey you two, thank you so much for your detailed reply – it’s been a great help. I’ll have a go at it this evening and will be happy to let you know how it goes.
One more question: is it better to do the exposure bracketing (to determine the exposure) with the filter already in place, or without it? If without, do I need to take an extension factor into account for the colour mixing heads, just as I do with the filter foils?
Urnes
Yes. You should measure directly with the filter in place, as the times get longer the tighter the filter is screwed in.
Once you’ve been working with it for a while, you’ll be able to make a rough estimate of the filter setting, carry out a test print, and then adjust it to the correct value.
Regards, Sven.
DennisG
Hi again,
As promised, here’s a print from yesterday.
I haven’t quite got the hang of the contrast yet.
The paper I used was: Ilford Multigrade IV RC DE LUXE
My settings on the colour mixing head were
Y=0; M=approx. 65
The print still lacks contrast, though I don’t think that’s the case with the negative. What could I have done differently here?
Increase the exposure and increase the contrast? Reduce the exposure time? Or turn the magenta down a bit again.
I’d be grateful for any tips so that I waste less paper next time. (The paper is absolutely outrageously expensive.)
Unfortunately, my scanner has increased the contrast in the attached image, but it’s close to the original.
Many thanks
Gast
It looks as though it hasn't been fully developed...
DennisG
That’s how it should actually be; I use Adox ECO NEUTOL at a dilution of 1:9. I developed the image for about 75 seconds.
As I said, the scanner boosted the contrast so much that I had to reduce it artificially. I’ll attach the scanned original below.
(The contrast here is clearly too high, which doesn’t reflect reality)
TR
Hi, if you want to position the light tones further away from the dark ones (for greater contrast), you’ll need to apply the appropriate filter. Why not try setting Y to 0 and M to the maximum?
Urnes
Looking at the photo, I’d say the negative has been overexposed at the bottom. It looks a bit washed out and isn’t really ideal.
For more contrast, add more magenta. If necessary, go right up to the maximum value. If all your photos need that much magenta, you may need to adjust your film development.
To try this out, you should pick up a pack of cheap paper like Fomatone.
Regards, Sven.
Morte
To avoid wasting paper, you need to make test strips. These can be really small or narrow to start with, so you can get the hang of it before printing the key parts of the image on a larger strip. Only once that looks good should you use a whole sheet for a proper test print.
