Black and White Contrast Control with a Color Enlarger

[pdeeh]

you are spending a lot of time turning dials .

hardly

 

[MartinP]

It would be instructive for the OP to make a couple of prints from some 'typical' negative, one print with maximum magenta and the other with maximum yellow. Try to match some mid-tone between the two prints and you will get an idea of how the two (notionally two, but there can be more for production practicality reasons) emulsions, high and low contrast, look.

Most often, burning-in and dodging will help achieve the final result you want and burning-in can be at a different grade to the rest of the print - this really helps with textures and shadows, or with filling highlights that are blank at the main exposure for example. There is a (there was a url link here which no longer exists) (in Enlarging) where a master printer explains how he approaches a new negative and I think to read that would be very useful for you.

 

[MattKing]

If you start with your filters set to zero, you are exposing your paper with lots of blue light, and lots of green light.

As you increase the magenta filtration, you are reducing the amount of green light hitting the paper.

As you increase the yellow filtration, you are reducing the amount of blue light hitting the paper.

Logically, it would make as much sense to start with both filters set to their maximum settings, and to calibrate your approach by decreasing the settings.

 

[RalphLambrecht]

I'm happy to send out a free pdf on how to calibrate your color head'scontrstand be speedmatched. just send a request to rlambrec@ymail.com.

 

[RalphLambrecht]

x2. If you enjoy wasting paper and practicing cuss words, stick with the colour head

sorry, but this is BS. color heads are great fot B&W work. I'll pick them over cold light any dtime

 

[RalphLambrecht]

x2. If you enjoy wasting paper and practicing cuss words, stick with the colour head

sorry, but this is BS.color heads are great fot B&W work. I'll pick them over cold light any dtime

 

[RalphLambrecht]

x2. If you enjoy wasting paper and practicing cuss words, stick with the colour head

sorry, but this is BS.color heads are great fot B&W work. I'll pick them over cold light anytime

 

[Matthew Cherry]

I have never had a problem printing with a color head and much prefer it to under the lens filters. Now, having said that, my favorite B&W enlarger has a VCCE module, but I find I can do the same by controlling both yellow and magenta.

 

[Jim Noel]

Some years ago the results of a test to learn the contrast range of various color heads when printing on VC paper was in one of the magazines of the time. The greatest range that any subtractive head accomplished was only 1.5-3.5.
You are better off sticking to the Ilford filters which will give you a full range of contrast.

 

[L Gebhardt]

hardly

So how do you do split grade printing on a color head without turning the knobs/dials to remove/add the magenta and yellow filters to do the hard then the soft exposures separately?

 

[pdeeh]

you are spending a lot of time turning dials

If you don't like using dials or knobs, that's fine. I simply think it's specious to suggest that it takes any more time to turn a dial or press a button than change a filter.

Split-grade printing has no bearing on my comment

 

[pentaxuser]

Some years ago the results of a test to learn the contrast range of various color heads when printing on VC paper was in one of the magazines of the time. The greatest range that any subtractive head accomplished was only 1.5-3.5.
You are better off sticking to the Ilford filters which will give you a full range of contrast.

So I think you are saying that the lowest grade you can get with even the best colour head is 1.5 which is only half a grade better than no filtration at all? This doesn't seem to ring true to me and if the range is as small as the article contends then I am surprised that this major drawback with colour heads isn't mentioned in more books.

Can you point to the source of the article? It would be interesting to know a few more details about the test regime, the enlargers in questions etc

Thanks

pentaxuser

 

[RalphLambrecht]

none of the color enlargers, I've tested were ever limited on thelow-contrst side full yellow filtering will give you an equivialent to filter number 0 or less on the high-contrst side some are indeed limited to ISO grade 5, which isn't much of a limitation as most negatives ,which require such a high contrastaren't worth printing in the first place.

 

[DREW WILEY]

I can make identical prints using either a conventional colorhead or split printing using hard tricolor blue and green filters under the lens, or even
with the direct blue and green channels of my true additive enlargers. But yeah, I guess there are some nearly hypothetical situations where,
at the very extremes of VC possibility, the hard filter would be the only one which worked. I don't know if any current VC papers are actually
that extreme to begin with... but it's pretty much an academic rather than practical question.

 

[piu58]

I use a color head and I find the use very convenient.

Dalo wrote:
> It is true that I need a new test trip after each new setting but it is not that annoying.

That is not necessary if you are in teh first stages of the photograph. Keep in mind that the shadow density (nearly) remains the same if you are changing magenta filtering. So if have a test strip with to less contrast use the time which gives full black and add more magenta. Quite simple.

 

[Ronald Moravec]

Using blended colors , in theory, allows one to maintain the same time when changing contrast. True if you want a repeatable middle grey. Most of us either want the new print to have the same white or black therefore I have to use a fudge factor.

If both colors are in the system, exposure times are longer than if we used no filter for #2, 15 M for 2.5, 30 M for #3 etc. I have forgotten the time increases, but it is obvious much more time is required the farther away from #2 . Increase yellow to go to 1.5, 1. .5, 0 & 00 15 cc for each half grade.

If you use 1.5 to 2.5, your time will be as short as possible because of the small filtration.

 

[L Gebhardt]

If you don't like using dials or knobs, that's fine. I simply think it's specious to suggest that it takes any more time to turn a dial or press a button than change a filter.

Split-grade printing has no bearing on my comment

If you had read my original comment you would see it was only about using a color head for split grade printing. For regular printing a color head is about as convenient as changing under the lens filters, and more flexible.

 

[pentaxuser]

I'll say it again as Ralph is too modest to "blow his own trumpet" but on his website he very kindly and free of charge gives dual filtration values for both Ilford and Agfa paper and the compensatory fractions of an f stop needed when changing grades up or down

Well worth a look.

pentaxuser

 

[RalphLambrecht]

thanks for the kind words.

 

[MattKing]

thanks for the kind words.

Ralph:

Any news on when we might see your website again (with all those nice, helpful aids included)? :confused:

 

[pentaxuser]

Sorry folks. I hadn't looked at the site for some time and anyway have Ralphs' book to which I refer, so I hadn't realised that the website seems to have disappeared

I can only echo MattKing's sentiments on its return

pentaxuser

 

[RalphLambrecht]

Sorry folks. I hadn't looked at the site for some time and anyway have Ralphs' book to which I refer, so I hadn't realised that the website seems to have disappeared

I can only echo MattKing's sentiments on its return

pentaxuser

until it does ,you may want to yrydwwwmonochrome.comas a replacement.the aid are in the 'tools' section.

 

[osprey48]

I only use one filter at a time, the rest set to 0. I use Ilford's tables, where zero Y and M = the equivalent to grade 2. Above grade 2, increase only the M filter, below grade 2, increase only the Y filter. My enlarger filters go up to 170. This method has worked for me for years, and I've been more than happy with the results. I have read that a colour head produces slightly less contrast than a mono head, but the difference would be minimal. Besides, I hardly ever print lower than grade 2, so the Y filter is almost never used.

 

[osprey48]

PS. To split grade print, expose first at one setting, adjust the filter then do the 2nd exposure.

 

[MattKing]

until it does ,you may want to yrydwwwmonochrome.comas a replacement.the aid are in the 'tools' section.

Ralph:

Do you mean www.monochrome.com?

I cannot find anything useful there.